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1
Naji, Hassan Khuder, Amjed Mirza Oda, Wesam Abdulaljeleel, Hussein Abdilkadhim e Rawaa Hefdhi. "ZNO-Ag/PS and ZnO/PS Films for Photocatalytic Degradation of Methylene Blue". Indonesian Journal of Chemistry 20, n. 2 (2 marzo 2020): 314. http://dx.doi.org/10.22146/ijc.41347.
Testo completoAbstract (sommario):
Two films of ZnO-Ag/polystyrene (ZnO-Ag/PS) and ZnO/polystyrene (ZnO/PS) have been prepared to evaluate the photodegradation ability of stabilized catalysts. The efficiency of ZnO improved against recombination of electron-hole pair by modification of catalyst surface with Ag photodeposition to be more resistant towards photocorrosion. ZnO-Ag catalyst was characterized by SEM and EDS analysis to show high roughness of this catalyst and Ag deposited on the surface was 2% (molar ratio). ZnO-Ag/PS and ZnO/PS composites were made as films and were then analyzed by FTIR spectra that showed the interaction of ZnO and ZnO-Ag with polystyrene appeared in the range of 400–620 cm–1, XRD pattern indicated the presence of Ag nanoparticles on the surface of ZnO and ZnO/PS film has maximum absorbance at 376 nm in UV-VIS spectra. This value shifted to 380 nm because of the photodeposition. The photocatalytic reaction was depicted using methylene blue (MB) in the UV-irradiation action of stacked films in MB solution. The result showed that both ZnO-Ag/PS and ZnO/PS films gave efficiency to remove MB by 97% and 70%, respectively. The reusability test of the films showed that ZnO-Ag/PS was more resistant than ZnO/PS. The presence of Ag also increased the efficiency in photodegradation and resistance against photocorrosion.
2
Yuan, Xiaohong, Qufu Wei, Huizhen Ke, Zujian Huang e Dongsheng Chen. "Structural color and photocatalytic property of polyester fabrics coated with Ag/ZnO composite films". International Journal of Clothing Science and Technology 31, n. 4 (5 agosto 2019): 487–94. http://dx.doi.org/10.1108/ijcst-09-2018-0112.
Testo completoAbstract (sommario):
Purpose The purpose of this paper is to prepare structural colors of fabrics coated with Silver/Zinc Oxide (Ag/ZnO) composite films by magnetron sputtering and analyze the relationship between the colors and the thickness of Zinc Oxide (ZnO) film in Ag/ZnO composite film and the photocatalytic property of the fabrics coated with Ag/ZnO composite film. Design/methodology/approach Ag/ZnO composite films deposited on polyester fabrics were prepared by magnetron sputtering technology. The structural colors of textiles coated with Ag/ZnO composite films and the relationship between the colors and Ag/ZnO composite films were analyzed, and the photocatalytic property of Ag/ZnO composite films was also discussed. Findings The results indicated that the colors varied with the thicknesses of the ZnO film in Ag/ZnO composite films. The reactive sputtering time of ZnO film was 5, 8, 10 and 14 min, respectively, and the colors of the corresponding fabrics were purple, blue, blue-green and yellow. Meanwhile, the polyester fabrics coated with Ag/ZnO composite films showed the excellent photocatalytic properties, and silver (Ag) films deposited under the ZnO films in Ag/ZnO composite films could also improve the photocatalytic activities of ZnO films, and the formaldehyde degradation rates was 77.5%, which was higher than the 69.9% for the fabrics coated only with the ZnO film. Originality/value The polyester fabrics coated with Ag/ZnO composite films not only created various structural colors using change the thicknesses of the ZnO film, but also achieved the multifuctionality, which will have a broad application prospect in textile fields.
3
Shang, Jian, Ye Sun, Teng Zhang, Zhen Liu e Hong Zhang. "Enhanced Antibacterial Activity of Ag Nanoparticle-Decorated ZnO Nanorod Arrays". Journal of Nanomaterials 2019 (30 aprile 2019): 1–7. http://dx.doi.org/10.1155/2019/3281802.
Testo completoAbstract (sommario):
Silver (Ag) has broad-spectrum antibacterial properties and is widely used in various fields, including in antibacterial coatings for orthopedic implants. For reasons of cost and cytotoxicity, improvement of the antibacterial efficiency of Ag is necessary. The scientific community has also shown a strong enthusiasm in this research area. In this paper, ZnO nanorod arrays were prepared on a titanium (Ti) substrate by seed-assisted hydrothermal method and Ag nanoparticles were deposited by magnetron sputtering to obtain Ag nanoparticle-decorated ZnO nanorod arrays (ZnO nanorods/Ag nanoparticles). The antibacterial properties of ZnO nanorods/Ag nanoparticles against Pseudomonas aeruginosa were systematically studied by agar diffusion method and were compared with other samples such as ZnO nanorod arrays and ZnO seed layer/Ag nanoparticles. The experimental results showed that ZnO nanorods/Ag nanoparticles displayed significantly higher antibacterial properties against Pseudomonas aeruginosa than other samples, including ZnO nanorod arrays and ZnO seed layer/Ag nanoparticles. These superior antibacterial properties originated predominantly from the morphological structure of ZnO nanorods, which optimized the particle size and distribution of Ag nanoparticles, greatly improving their antimicrobial efficiency. The synergistic antibacterial properties of Ag nanoparticles and ZnO nanorods make Ag nanoparticle-decorated ZnO nanorod arrays a promising candidate for antibacterial coating of orthopedic implants.
4
Vu, Anh-Tuan, Thi Anh Tuyet Pham, Thi Thuy Tran, Xuan Truong Nguyen, Thu Quynh Tran, Quang Tung Tran, Trong Nghia Nguyen et al. "Synthesis of Nano-Flakes Ag•ZnO•Activated Carbon Composite from Rice Husk as A Photocatalyst under Solar Light". Bulletin of Chemical Reaction Engineering & Catalysis 15, n. 1 (4 febbraio 2020): 264–79. http://dx.doi.org/10.9767/bcrec.15.1.5892.264-279.
Testo completoAbstract (sommario):
This study aimed to synthesize Ag•ZnO•Activated carbon (Ag•ZnO•AC ) composite from rice husk for degradation of dyes. The deposition of Ag and ZnO on AC led to decreasing the surface area and pore volume of Ag•ZnO•AC composite. In addition, when Ag and ZnO were dispersed on activated carbon, the Ag•ZnO flakes became denser and tighter, but the particle size of Ag became smaller from 5 to 7 nm. The photocatalytic ability of Ag•ZnO•AC composite was evaluated by degradation of Janus Green B (JGB) and compared with that of AC, ZnO, Ag•ZnO, and ZnO•AC samples. The effects of catalyst dosages, pH values, and initial dye concentrations on photocatalytic degradation were investigated in detail. The Ag•ZnO•AC composite had a high degradation efficiency of 100% in 60 min, showing the reaction rate of 0.120 min-1 and degradation capacity of 17.8 mg/g within 20 min. The photocatalytic performance of the Ag•ZnO•AC composite was also evaluated by cyclic test and the degradation of other persistent dyes such as Methylene Blue, Tartrazine, Congo Red, and organic compounds (Caffeine and Bisphenol A). Based on the experimental results, the possible destruction route of JGB by the as-synthesized Ag•ZnO•AC composite was suggested. Copyright © 2020 BCREC Group. All rights reserved
5
Yi, Zhigang, Tao Jiang, Ying Cheng e Qiong Tang. "Effect of SiO2 aerogels loading on photocatalytic degradation of nitrobenzene using composites with tetrapod-like ZnO". Nanotechnology Reviews 9, n. 1 (23 ottobre 2020): 1009–16. http://dx.doi.org/10.1515/ntrev-2020-0081.
Testo completoAbstract (sommario):
AbstractTo study the effect of improved adsorption property of tetrapod-like ZnO (T-ZnO) on its photocatalytic performance, a new composite was prepared by loading silica aerogels (SiO2(AG)) on the surface of T-ZnO via the sol–gel method. Various characterization methods showed that SiO2(AG) was uniformly loaded on the surface of T-ZnO, and the morphology as well as structural characteristics of SiO2(AG) and T-ZnO were not changed. Nitrobenzene (NB) was selected as the model pollutant, and the adsorption and photocatalytic properties of T-ZnO and SiO2(AG)/T-ZnO for NB were studied. The photocatalytic degradation processes of NB using T-ZnO and SiO2(AG)/T-ZnO followed the first-order reaction. Considering the initial moment reaction kinetic, the photocatalytic kinetic of SiO2(AG)/T-ZnO and T-ZnO was consistent with the Langmuir–Hinshelwood kinetic model, and reaction rate constant {k}_{{\text{SiO}}_{2}\left(\text{AG}\right)/\text{T-ZnO}}^{^{\prime} }\gt {k}_{\text{T-ZnO}}^{^{\prime} }, adsorption rate constant {K}_{\text{ad}{\text{SiO}}_{2}(\text{AG})/\text{T-ZnO}} > Kad T-ZnO, which demonstrated that SiO2(AG) loading could increase T-ZnO adsorption to NB, then promoted its photocatalytic performance.
6
Hu, Ya Wei, Hui Rong He, Xia Kong e Yang Min Ma. "Synthesis and Antibacterial Activities of Ag/ZnO Nanoparticles". Key Engineering Materials 697 (luglio 2016): 714–17. http://dx.doi.org/10.4028/www.scientific.net/kem.697.714.
Testo completoAbstract (sommario):
Ag/ZnO nanoparticles with different Ag concentrations were fabricated through sol-gel method under 500 °C for 60 min with a heating rate 5 °C·min-1. The phase, the crystallographic structure and the surface topography of the Ag/ZnO nanoparticles were charactered by XRD and SEM. The antibacterial activities of the Ag/ZnO nanoparticles were performed by disc diffusion method. The results indicate that the as-prepared Ag/ZnO nanoparticles display great antibacterial activity than ZnO nanoparticle without Ag doping. And Ag/ZnO nanoparticles with 5 mol% Ag concentration show more excellent antibacterial activity toward S.aureus, B. subtilis, E. coli and P. aeruginosa with diameters zones of inhibition 21.7, 18.5, 18.4 and 17.8 mm than other Ag/ZnO nanoparticles. And the mechanism of ZnO antibacterial activity is discussed.
7
Hsueh, Yi-Huang, Chien-Te Hsieh, Shu-Ting Chiu, Ping-Han Tsai, Chia-Ying Liu e Wan-Ju Ke. "Antibacterial Property of Composites of Reduced Graphene Oxide with Nano-Silver and Zinc Oxide Nanoparticles Synthesized Using a Microwave-Assisted Approach". International Journal of Molecular Sciences 20, n. 21 (29 ottobre 2019): 5394. http://dx.doi.org/10.3390/ijms20215394.
Testo completoAbstract (sommario):
Graphene oxide (GO) composites with various metal nanoparticles (NPs) are attracting increasing interest owing to their broad scope in biomedical applications. Here, microwave-assisted chemical reduction was used to deposit nano-silver and zinc oxide NPs (Ag and ZnO NPs) on the surface of reduced GO (rGO) at the following weight percentages: 5.34% Ag/rGO, 7.49% Ag/rGO, 6.85% ZnO/rGO, 16.45% ZnO/rGO, 3.47/34.91% Ag/ZnO/rGO, and 7.08/15.28% Ag/ZnO/rGO. These materials were tested for antibacterial activity, and 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO exhibited better antibacterial activity than the other tested materials against the gram-negative bacterium Escherichia coli K12. At 1000 ppm, both these Ag/ZnO/rGO composites had better killing properties against both E. coli K12 and the gram-positive bacterium Staphylococcus aureus SA113 than Ag/rGO and ZnO/rGO did. RedoxSensor flow cytometry showed that 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO decreased reductase activity and affected membrane integrity in the bacteria. At 100 ppm, these two composites affected membrane integrity more in E. coli, while 7.08/15.28% Ag/ZnO/rGO considerably decreased reductase activity in S. aureus. Thus, the 3.47/34.91% and 7.08%/15.28% Ag/ZnO/rGO nanocomposites can be applied not only as antibacterial agents but also in a variety of biomedical materials such as sensors, photothermal therapy, drug delivery, and catalysis, in the future.
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Kalnaowakul, Phuri, Tonghathai Phairatana e Aphichart Rodchanarowan. "Photocatalytic Comparative Study of TiO2, ZnO, Ag-G-ZnO and Ag-G-TiO2 Nanocomposite Films". Key Engineering Materials 751 (agosto 2017): 825–30. http://dx.doi.org/10.4028/www.scientific.net/kem.751.825.
Testo completoAbstract (sommario):
In this study, the photocatalytic properties and morphology of TiO2, ZnO, Ag-graphene-zinc oxide (Ag-G-ZnO) and Ag-graphene-titanium dioxide (Ag-G-TiO2) nanocomposite were compared. The Ag-G-ZnO and Ag-G-TiO2 nanocomposite were successfully prepared by thermal decomposition of colloidal solution. These prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and photocatalytic activities. The results from XRD patterns show that Ag-G-TiO2 composites and the Ag-G-ZnO nanocomposites were in the form of fcc and hcp crystal structure, respectively. The SEM images show that at calcination of 500 °C for 3 h, the composite thin film of Ag-G-ZnO and Ag-G-TiO2 were homogenous. In the case of the photocatalytic experiments using methylene blue dye (MB) under UV irradiation, the order of the photocatalytic activities from high to low performances are Ag-G-ZnO, Ag-G-TiO2, ZnO and TiO2, respectively.
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Wen, Jing, Chun Ying Zuo e Cheng Zhong. "Ab Initio Investigations of Electronic Structure and Optical Properties of Ag-F Codoped ZnO". Advanced Materials Research 152-153 (ottobre 2010): 1097–102. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1097.
Testo completoAbstract (sommario):
Motivated by the widely discussed Ag doped ZnO and the lack of follow-up reports about the realization of p-n junctions, we calculated the electronic structures and optical properties of pure, Ag-doped and Ag-F codoped ZnO based on the density-functional theory. It was found that Ag doped ZnO shows p-type conduction character. But there are some unstable factors and self-compensations in this structure. We also calcualted the formation energy and ionization energy of the impurity for Ag-F codoped ZnO. It was found that incorporating the reactive donor F into Ag doped ZnO system, not only enhances the Ag acceptor solubility, but also gets a shallower Ag acceptor energy level in the band gap. In addition, we analyze the imaginary part of the dielectric function, reflectivity and absorption coefficient for pure ZnO and Ag-F codoped ZnO. Compared with the pure ZnO, the remarkable feature for Ag-F codoped ZnO is that there is a strong absorption in the visible-light region, which indicates that it could be taken as a potential candidate for a photocatalytic material.
10
Saratovskii, A. S., K. Yu Senchik, A. V. Karavaeva, S. K. Evstropiev e N. V. Nikonorov. "Photo-oxygenation of water media using photoactive plasmonic nanocomposites". Journal of Chemical Physics 156, n. 20 (28 maggio 2022): 201103. http://dx.doi.org/10.1063/5.0094408.
Testo completoAbstract (sommario):
Plasmonic nanocomposites ZnO–Ag and ZnO–SnO2–Ag(AgCl) were prepared by the polymer–salt method, and their structure and morphology were studied using XRD and SEM analyses. It was found that the addition of photoactive inorganic nanocomposites ZnO–Ag and ZnO–SnO2–Ag(AgCl) in pure water significantly enhances the effectiveness of its disinfection and purification during UV treatment and provides the effective water oxygenation. Oxygen photogeneration under blue light (λex. = 405 nm) can be related to the plasmon-excitation processes in ZnO–SnO2–Ag(AgCl) composites. Prepared composites demonstrate antibacterial activity against both Gram-positive and Gram-negative bacteria. The increase of Ag content in ZnO–Ag and ZnO–SnO2–Ag(AgCl) composites significantly enhances their antibacterial activity.
11
A, Rathika, e Irine T. M. "SYNTHESIS OF SILVER (Ag) DOPED ZINC OXIDE (ZnO) NANOPARTICLES AS EFFICIENTPHOTOCATALYTIC ACTIVITY FOR DEGRADATION METHYLENE BLUE DYE". Journal of Advanced Scientific Research 13, n. 02 (31 marzo 2022): 129–35. http://dx.doi.org/10.55218/jasr.202213217.
Testo completoAbstract (sommario):
Zinc oxide (ZnO) and silver doped zinc oxide (Ag-ZnO) nanoparticles were prepared using zinc nitrates as oxidizers, glycine and citric acid as fuels as solution combustion synthesis (SCS) at 500°C. X-ray diffraction (XRD) pattern demonstrates the presence of Ag+ in the hexagonal zincite structure of ZnO. The average crystalline size of the particles of ZnO and Ag-ZnO were found to 47 nm and 74 nm respectively. From the Fourier transform infrared (FTIR) spectrum, the composition of Ag doped ZnO confirmed Ag-Zn-O stretching vibration at 510 cm-1. The UV-Visible absorption spectra results showed that synthesized ZnO and Ag-ZnO nanoparticles exhibited UV-visible absorption peaks at 370 nm, corresponds to a band gap of 3.24 eVand 3.08 eV respectively. Based on the above characterization techniques, the incorporation of silver affects the structural and optical behaviour of ZnO nanoparticles. The ZnO nanoparticles were observed that the particles are spherical morphologies. EDAX spectrum indicates no other elemental presence in the synthesized nanoparticle. The present work illustrate the Ag-ZnO nanoparticles as a photo-catalyst to decompose contaminants in the presence of UV light. The photo-catalytic activity of ZnO samples were investigated by UV- irradiation of methylene blue solution in a photocatalytic setup. The resulting mixtures were irradiated with UV light for a period of 45 mins. Based on results, the photocatalytic activity of Ag-ZnO nanoparticles were enhanced by the addition of Ag in pure ZnO nanoparticles. Ag doped ZnO nanoparticles showed higher photocatalytic activity efficiency than pure ZnO nanoparticles.
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Venugopal, N., e Anirban Mitra. "Plasmonics Properties of ZnO/Ag/ZnO Multilayer Thin Films". Advanced Materials Research 585 (novembre 2012): 214–18. http://dx.doi.org/10.4028/www.scientific.net/amr.585.214.
Testo completoAbstract (sommario):
The optical properties of ZnO (Zinc Oxide)/Ag (silver)/ZnO (Zinc Oxide)/glass multilayer structure have been investigated. These properties could be tuned using the plasmonic properties of the intermediate Ag layer. ZnO thin film of 80 nm thickness has been deposited using Spray Pyrolysis on Glass Substrate. Prior to the deposition of approximately same thickness of ZnO like the previous one, a thin layer of Ag with thicknesses varying from 0.5 nm to 10 nm have been deposited using Vacuum Deposition. We have correlated the properties of multilayer thin film with thickness and morphology of the intermediate silver layer. Crystallographic properties of thin films have been characterized using XRD (X-ray Diffraction). Surface Morphology of Ag layer on ZnO has been studied using AFM (Atomic Force Microscopy). UV-VIS Spectrometer has been used to measure the optical transparency of these multilayer thin films. It has been observed that optical transparency of ZnO/Ag/ZnO/Glass thin film on glass substrate slightly enhanced compared to ZnO/ZnO/Glass. We interpret these experimental results with Maxwell-Garnett theory. The simulated and experimental SPR (Surface Plasmon Resonance) positions of ZnO/Ag/ZnO thin films are well matched. We expect that MG Theory interpretation of these kind Dielectric/Metal/Dielectric multilayer thin films were applicable only for Metallic Island thin films deposited using Vacuum coating method. We also describe the influence of Ag thickness on optical properties of the ZnO/Ag/ZnO composite and suggest a mechanism of tunability influenced by surface plasmons.
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Floro, J. A., J. R. Michael, L. N. Brewer e J. W. P. Hsu. "Preferred heteroepitaxial orientations of ZnO nanorods on Ag". Journal of Materials Research 25, n. 7 (luglio 2010): 1352–61. http://dx.doi.org/10.1557/jmr.2010.0179.
Testo completoAbstract (sommario):
Wurtzite ZnO nanorods were grown from solution onto coarse-grain bulk polycrystalline Ag substrates to explore the nature of preferred heteroepitaxial orientations. ZnO nanorods grow copiously on grains with <111> and <001> surface normals. Two epitaxial orientations were observed: {0001} ZnO ‖ {111} Ag with <20> ZnO ‖ <10> Ag and {0001} ZnO ‖ {001} Ag with <20> ZnO ‖ <10> Ag. Both feature ZnO basal plane growth, and the specific in-plane orientation relationships both feature alignment of close-packed directions in the interface. Nanorod growth was strongly suppressed on Ag grains in most other orientations. Although strain energy minimization is often invoked to explain the {0001} ZnO ‖ {111} Ag with <20> ZnO ‖ <10> Ag orientation, associated with an almost ideal near-coincidence site lattice matching, our data suggests that strain may not be the sole, or even the most important, determinant of the preferred orientations during solution-based epitaxial growth in this system.
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Cai, Yu, Chengbao Yao e Jie Yuan. "Enhancement of Photoelectrochemical Performance of Ag@ZnO Nanowires: Experiment and Mechanism". Journal of Nanomaterials 2020 (20 marzo 2020): 1–9. http://dx.doi.org/10.1155/2020/6742728.
Testo completoAbstract (sommario):
This paper focuses on the enhancement of photoelectrochemical (PEC) performance of uniform silver nanoparticles-decorated ZnO (Ag@ZnO) nanowires, which have been synthesized by two-step chemical vapor deposition to prepare ZnO nanowires then magnetron sputtering method to deposit Ag nanoparticles. Moreover, we analyzed the mechanisms of the PEC behavior of the Ag@ZnO nanowires. The PEC characteristics show that the current density of Ag@ZnO nanowires increased comparing to that of unmodified ZnO nanowires. The optimized content of the Ag-decorated ZnO photoelectrode is up to the maximum photocurrent density of 24.8 μAcm-2 at 1 V vs. Ag/AgCl, which was almost four times than that of the unmodified ZnO photoelectrode. Based on the surface plasmon resonance (SPR), effect of Ag nanoparticles was enhanced PEC performance of the Ag@ZnO nanowires. Because SPR effect of Ag nanoparticles extended the light absorption and enhanced the separation efficiency of the photogenerated electron-hole pairs. The remarkable PEC properties offer metals-semiconductor compound nanostructures materials as a promising electron source for high current density applications.
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NIE, Jingkai, Guangke WANG, Dong HOU, Fu GUO e Yu HAN. "The Preparation and Research on the Electromagnetic Shielding Effectiveness of T-ZnO@Ag/Silicone Rubber Composites". Materials Science 26, n. 2 (18 dicembre 2019): 205–9. http://dx.doi.org/10.5755/j01.ms.26.2.21286.
Testo completoAbstract (sommario):
This study first conducted surface modification of Ag-plated Tetrapod-like zinc oxide (T-ZnO) whiskers with the use of dopamine and prepared Ag-plated T-ZnO whiskers (T-ZnO@Ag) by means of chemical plating, in which AgNO3 solutions with different concentrations were used during the preparation. Micro-structures of the prepared T-ZnO@Ag powders were examined to evaluate the effect of AgNO3 concentration on Ag plating performance. Subsequently, conductive Si rubber samples were prepared, the T-ZnO@Ag powders were used as fillers, and the effectiveness of the related electromagnetic shielding was investigated in detail. The results showed that using AgNO3 solution with a concentration of 20 g/L, a continuous Ag coating-layer was observed on the surface of T-ZnO whiskers. It was evident that, when used as fillers, T-ZnO@Ag has a conductive threshold and when the mass fraction of the fillers exceeded 50 %, the T-ZnO@Ag whiskers that were uniformly dispersed in the matrix formed interconnected conductive paths. In this condition, the electromagnetic shielding effectiveness of the prepared T-ZnO@Ag/Si rubber composite reached up 90 dB.
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Azhar J. Bohan, Ghaed K. Salman e Duha S. Ahmed. "Enhanced bioactivity of Pure ZnO and ZnO-Ag nanocomposite Using Sol-Gel method for Self-Cleaning Application". International Journal of Research in Pharmaceutical Sciences 10, n. 4 (18 novembre 2019): 3649–56. http://dx.doi.org/10.26452/ijrps.v10i4.1748.
Testo completoAbstract (sommario):
In the current study, Pure ZnO and Ag-ZnO nanocomposite are established using the sol-gel method with the influence of ammonia solution NH4OH to incorporate Ag ions into ZnO and form Ag-ZnO nanocomposites. Then pure ZnO and Ag-ZnO nanocomposites were annealed at 450oC for tow h in a muffle furaning using temperture controlling, and heat rate was set at temperature 100oC per min. The structural and morphological properties of samples were characterized using XRD, FTIR, and FESEM with Energy dispersive X-rays (EDX). In addition, the antibacterial activity of pure ZnO and Ag- ZnO nanocomposite was evaluated against gram-positive and gram-negative organisms by plate count test. The results of the test revealed strong antibacterial behavior of nanocomposite against bacteria as compared to pure ZnO and improved efficiency of incorporation Ag ion on ZnO.
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Li, Yong, Ya Liang Chen e Yan Qun Shao. "Study on the Photocatalytic Degradation of MB by the ZnO@PDA and ZnO-Ag@PDA". Journal of Nano Research 84 (20 settembre 2024): 67–81. http://dx.doi.org/10.4028/p-titte7.
Testo completoAbstract (sommario):
Photocatalysis properties enhanced by metal and organic polymer has been received more interest because of their ability to directly or indirectly degrade pollutants. The effect of PDA (polydopamine) and Ag nanoparticles on the different phases of ZnO to degrade organic dyes under visible and UV-vis light was investigated. ZnO@PDA, ZnO-Ag, and ZnO-Ag@PDA nanoparticles were synthesized. It’s shown that Ag particles with sizes of less than 20 nm were deposited evenly on the ZnO. There were a few changes in the structure of ZnO@PDA or ZnO-Ag @PDA. When the ZnO was coated by PDA, the photocatalytic activity could be enhanced. The photocatalytic activity under UV-vis and visible light of the ZnO@PDA were effectively improved. The degradation rate of ZnO-Ag@PDA was 97.9% under UV-vis light for 20 mins, which was 16.1% higher than that of ZnO. The photocatalytic activity of ZnO-Ag@PDA reached the maximum after polymerizing for 2 hours. The photocatalytic efficiency of ZnO-Ag@PDA-2h under UV-vis for 30 minutes can reach higher than 99.01%. The photocatalytic performance decreased rapidly with the increasing cycles. When the number of cycles was 5, the degradation rate was 65.84%. Afterward, the degradation rate changed small and became stable.
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Ding, Chao, Kun Fu, Yishuai Pan, Jia Liu, Huiping Deng e Jun Shi. "Comparison of Ag and AgI-Modified ZnO as Heterogeneous Photocatalysts for Simulated Sunlight Driven Photodegradation of Metronidazole". Catalysts 10, n. 9 (22 settembre 2020): 1097. http://dx.doi.org/10.3390/catal10091097.
Testo completoAbstract (sommario):
Ag and AgI-modified ZnO composites (Ag/ZnO and AgI/ZnO) were synthesized in facile ways. The photocatalysts were used for the photodegradation of metronidazole (MNZ) under the irradiation of simulated sunlight. The results of experiments showed that both Ag/ZnO and AgI/ZnO had a specific molar ratio to reach the best performance. Ag/ZnO performed better in the photodegradation of MNZ than AgI/ZnO under the same conditions. The reaction rate constant of AgI/ZnO was less affected by the variation of initial concentration of MNZ or pH values. The main reactive oxygen species of the photocatalytic process are OH, O2− and h+, but the free radicals which play the most critical part differ in Ag/ZnO and AgI/ZnO. Several intermediates were revealed by LC–MS/MS analysis. The stability of the photocatalysts was evaluated by a series of repeated MNZ photodegradation experiments. The results showed that AgI/ZnO had better stability than Ag/ZnO.
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Thu, Phung Thi, Vu Duy Thinh, Vu Dinh Lam, Ta Ngoc Bach, Le Thi Hong Phong, Do Hoang Tung, Do Hung Manh, Nguyen Van Khien, Trinh Xuan Anh e Ngo Thi Hong Le. "Decorating of Ag and CuO on ZnO Nanowires by Plasma Electrolyte Oxidation Method for Enhanced Photocatalytic Efficiency". Catalysts 12, n. 7 (21 luglio 2022): 801. http://dx.doi.org/10.3390/catal12070801.
Testo completoAbstract (sommario):
In this work, photocatalytic performance is divulged in the ternary CuO-Ag-ZnO nanowire synthesized via a two-step approach. The decoration of Ag and CuO nanostructures onto the surface of ZnO nanowires was simply carried out by using the plasma electrolytic oxidation method in a short time. The structure, size, morphology, and optical properties of as-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, and spectrophotometry measurements. The diameters of Ag nanoparticles and ZnO nanoflowers are in the range of 5–20 nm and 20–60 nm, respectively. Within the first 15 min, methyl orange was decolorized 96.3 and 82.8% in the CuO-Ag-ZnO and Ag-ZnO, respectively, and there is only about 46.7% of that decomposed in pure ZnO. The CuO-Ag-ZnO shows a higher rate constant k = 0.2007 min−1 and a lower half-life time t = 6.1 min compared to Ag-ZnO and bare ZnO nanowires. The photo-reusability of the ternary nanostructures was estimated to be much outweighed compared to ZnO nanowires. Interestingly, the synergic incorporation between noble metal–semiconductor or semiconductor–semiconductor in the interfaces of Ag-CuO, Ag-ZnO, and CuO-ZnO expands the visible light absorption range and eliminates the photogenerated electron–hole recombination, resulting in a superior visible-light-driven photocatalyst.
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Taringan, Agres K., Audy D. Wuntu e Henry F. Aritonang. "Kinetika Fotodegradasi Remazol Yellow Menggunakan Fotokatalis ZnO dan ZnO-Ag". Jurnal MIPA 6, n. 2 (25 ottobre 2017): 68. http://dx.doi.org/10.35799/jm.6.2.2017.17762.
Testo completoAbstract (sommario):
Telah dilakukan penelitian tentang kinetika fotodegradasi remazol yellow dengan menggunakan ZnO dan ZnO yang disisipi 1%, 3%, 5%, 7%, dan 9% Ag yang disintesis dengan metode kopresipitasi. Eksperimen kinetika dilakukan melalui penentuan konsentrasi remazol yellow yang tersisa setelah interaksi ZnO dan ZnO-Ag dengan larutan remazol yellow yang disinari UV selama 0, 20, 40, 60, 80, 100, 120 dan 140 menit. Selanjutnya data dianalisis mengikuti model kinetika reaksi orde pertama. Hasil penelitian menunjukkan bahwa laju reaksi fotodegradasi oleh ZnO meningkat dengan penambahan konsentrasi dopan AgA research on photodegradation kinetics of remazol yellow using ZnO and Ag-doped ZnO (1, 3, 5, 7 and 9 wt% Ag) synthesized by co-precipitation method had been studied. Kinetics experiment was performed by determining the concentration of remazol yellow remained after interaction of ZnO and ZnO-Ag with remazol yellow solution that were irradiated by UV-light at 0, 20, 40, 60, 80, 100, 120 and 140 minutes. Data obtained was analyzed using firs-order kinetics model. The results showed that photodegradation rate was increased with the increasing Ag concentration.
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Nigussie, Gebretinsae Yeabyo, Gebrekidan Mebrahtu Tesfamariam, Berhanu Menasbo Tegegne, Yemane Araya Weldemichel, Tesfakiros Woldu Gebreab, Desta Gebremedhin Gebrehiwot e Gebru Equar Gebremichel. "Antibacterial Activity of Ag-Doped TiO2 and Ag-Doped ZnO Nanoparticles". International Journal of Photoenergy 2018 (2018): 1–7. http://dx.doi.org/10.1155/2018/5927485.
Testo completoAbstract (sommario):
We report in this paper antibacterial activity of Ag-doped TiO2 and Ag-doped ZnO nanoparticles (NPs) under visible light irradiation synthesized by using a sol-gel method. Structural, morphological, and basic optical properties of these samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum, and UV-Vis reflectance. Room temperature X-ray diffraction analysis revealed that Ag-doped TiO2 has both rutile and anatase phases, but TiO2 NPs only have the anatase phase. In both ZnO and Ag-doped ZnO NPs, the hexagonal wurtzite structure was observed. The morphologies of TiO2 and ZnO were influenced by doping with Ag, as shown from the SEM images. EDX confirms that the samples are composed of Zn, Ti, Ag, and O elements. UV-Vis reflectance results show decreased band gap energy of Ag-doped TiO2 and Ag-doped ZnO NPs in comparison to that of TiO2 and ZnO. Pathogenic bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, were used to assess the antibacterial activity of the synthesized materials. The reduction in the viability of all the three bacteria to zero using Ag-doped ZnO occurred at 60 μg/mL of culture, while Ag-doped TiO2 showed zero viability at 80 μg/mL. Doping of Ag on ZnO and TiO2 plays a vital role in the increased antibacterial activity performance.
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Pang, Xinzhu, Nathan Skillen, Detlef W. Bahnemann, David W. Rooney e Peter K. J. Robertson. "Photocatalytic H2O2 Generation Using Au-Ag Bimetallic Alloy Nanoparticles loaded on ZnO". Catalysts 12, n. 9 (24 agosto 2022): 939. http://dx.doi.org/10.3390/catal12090939.
Testo completoAbstract (sommario):
Hydrogen peroxide (H2O2) is an important chemical as it is an environmentally friendly oxidant for organic synthesis and environmental remediation as well as a promising candidate for the liquid fuel. Photocatalytic generation of H2O2 is sustainable, and many efforts have been put into the development of new catalysts to gain high H2O2 yields. In this investigation, Au/ZnO, Ag/ZnO and Au-Ag/ZnO catalysts were prepared by the simultaneous impregnation of HAuCl4 and AgNO3 and they were used to generate H2O2 from a methanol/O2 system. It was demonstrated that Au/ZnO had the best performance at generating H2O2. The presence of Au on ZnO accelerated the generation of H2O2 on ZnO and facilitated H2O2 adsorption onto the catalyst surface, which resulted in the reaction kinetics changing from zero-order to first-order. Ag atoms on Ag/ZnO were unstable and would strip from the surface of ZnO during irradiation, decreasing the yield of H2O2. The stabilization of Ag on Au-Ag/ZnO depended on the ratio of Au and Ag. Au0.1Ag0.2/ZnO was a stable catalyst and it showed that the presence of Ag promoted the formation and decomposition of peroxide, simultaneously.
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Jose, Y. Jerlin, S. Joseph Selvaraj e M. Manjunathan. "Synthesis, Characterization, Photocatalytic Activities and Reusability of Eu-ZnO-Ag Nanoparticles using Sunlight/LEDs Illuminations". Asian Journal of Chemistry 31, n. 4 (27 febbraio 2019): 813–19. http://dx.doi.org/10.14233/ajchem.2019.21745.
Testo completoAbstract (sommario):
Photocatalyst (Eu–ZnO–Ag) was synthesized by precipitation-decomposition process. The characterization catalyst by phase and size of catalyst by powder-XRD, morphology of catalyst by FE-SEM and optical properties by UV-visible and emission spectroscopy. The photocatalytic action of Eu–ZnO–Ag was investigated in the photodegradation of methylene blue dye in water under LEDs/ solar light. Eu–ZnO–Ag catalyst is indicating the excellent activity than Ag–ZnO, Eu–ZnO commercial ZnO/TiO2 nanoparticles. Co-dopants (Eu/Ag) shift the light absorbance of ZnO toward visible region. Factor affecting of photodegrdation study by dose, dye, solution pH on of methylene blue dye present solar/LEDs. The Eu–ZnO–Ag is established to be reusable photocatalyst. A potential photodegradation of methylene blue mechanism was discussed under illuminations LEDs/solar light.
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Li, Juan, Jian Yan, Chengzhan Liu, Lihong Dong, Hui Lv, Wendong Sun e Shuangxi Xing. "Manipulation on ZnO heterostructures: from binary ZnO–Ag to ternary ZnO–Ag–polypyrrole". CrystEngComm 16, n. 48 (2014): 10943–48. http://dx.doi.org/10.1039/c4ce01551g.
Testo completoAbstract (sommario):
A ternary composite ZnO–Ag–polypyrrole was synthesized through a fast reaction between zinc acetate and hexamethylenetetramine followed by an in situ surface polymerization process. The sample exhibited a superior catalytic performance in the degradation of methylene blue under both UV irradiation and visible light.
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Liu, Xingzuo, Zhuo Chen, Yue Zhao, Yue Shen, Yun Guo, Jian Huang, Jiahua Min e Linjun Wang. "The study of metal enhanced fluorescence property of Ag/ZnO composite structure". Modern Physics Letters B 31, n. 07 (10 marzo 2017): 1750073. http://dx.doi.org/10.1142/s0217984917500737.
Testo completoAbstract (sommario):
In this paper, Ag nanoparticles were successfully prepared by chemical reduction, and then Ag/ZnO composite particles were successfully prepared and deposited onto glass substrates to form Ag/ZnO thin films. Hereafter, the structure, the morphology and the metal enhanced fluorescence (MEF) property of Ag nanoparticles and ZnO/Ag composite particles were studied by XRD, SEM, EDS, TEM, UV-vis absorption and fluorescence (FL) spectrometer. The results showed that the average size of Ag nanoparticles increased with the increase of prepared time. Moreover, ZnO layer consisted of polycrystalline structure and amorphous interface layer, but nano-Ag particle was polycrystalline structure. Annealing process was carried out to investigate the influence of annealing process parameters on MEF property of Ag/ZnO composite structure. Due to annealing treatment, the amorphous component of Ag/ZnO thin films was reduced, which might improve the density of Ag/ZnO thin films and the diameter of composite particles. Furthermore, FL enhancement phenomenon of fluorescein isothiocyanate (FITC) molecules might be attributed to the joint influence of the roughness and the density of these films and the average diameter of composite particles.
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Alahmadi, Nadiyah, e Mahmoud A. Hussein. "Impact of Ag/ZnO Reinforcements on the Anticancer and Biological Performances of CA@Ag/ZnO Nanocomposite Materials". Molecules 28, n. 3 (29 gennaio 2023): 1290. http://dx.doi.org/10.3390/molecules28031290.
Testo completoAbstract (sommario):
In this study, an unpretentious, non-toxic, and cost-effective dissolution casting method was utilized to synthesize a group of anticancer and biologically active hybrid nanocomposite materials containing biopolymer cellulose acetate. Pristine ZnO and Ag(0.01, 0.05, 0.1)/ZnO hybrid nanofillers based on variable Ag NP loadings were prepared via green procedures in the presence of gum arabic (GA). The chemical structures and the morphological features of the designed nanocomposite materials were investigated by PXRD, TEM, SEM, FTIR, TGA, and XPS characterization techniques. The characterization techniques confirmed the formation of CA@Ag(0.01, 0.05, 0.1)/ZnO hybrid nanocomposite materials with an average crystallite size of 15 nm. All investigated materials showed two degradation steps. The thermal stability of the fabricated samples was ranked in the following order: CA/ZnO < CA@Ag(0.01)/ZnO < CA@Ag(0.05)/ZnO = CA@Ag(0.1)/ZnO. Hence, the higher Ag doping level slightly enhanced the thermal stability. The developed nanocomposites were tested against six pathogens and were used as the target material to reduce the number of cancer cells. The presence of Ag NPs had a positive impact on the biological and the anticancer activities of the CA-reinforced Ag/ZnO composite materials. The CA@Ag(0.1)/ZnO hybrid nanocomposite membrane had the highest antimicrobial activity in comparison to the other fabricated materials. Furthermore, the developed CA@Ag(0.1)/ZnO hybrid nanocomposite material effectively induced cell death in breast cancer.
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Jha, Pankaj Kumar, Chamorn Chawengkijwanich, Chonlada Pokum, Pichai Soisan e Kuaanan Techato. "Antibacterial Activities of Biosynthesized Zinc Oxide Nanoparticles and Silver-Zinc Oxide Nanocomposites using Camellia Sinensis Leaf Extract". Trends in Sciences 20, n. 3 (15 gennaio 2023): 5649. http://dx.doi.org/10.48048/tis.2023.5649.
Testo completoAbstract (sommario):
Green route of nanomaterials synthesis is increasing in demand due to ecofriendly to the environment. In this research, objective is to biosynthesize and evaluate the antibacterial performance of pure ZnO and Ag/ZnO nanocomposites using Camellia sinensis leaf extracts. Pure ZnO nanoparticles and Ag/ZnO nanocomposites were synthesized using Camellia sinensis leaf extract. The antibacterial effectiveness against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria were examined and compared with 1 % Chlorox as a commercial disinfectant by well diffusion method based on the zone of inhibition. Pure ZnO nanoparticles and Ag/ZnO nanocomposites had hexagonal shape ZnO nanoparticles and rectangular shape Ag nanoparticles in Ag/ZnO nanocomposites with a particle crystal size between 20 - 30 nm with carboxylic and phenolic functional group attached on it. Ag/ZnO nanocomposites exhibited antibacterial effectiveness against both gram-positive and gram-negative bacteria, while pure ZnO nanoparticles exhibited antibacterial effectiveness against only gram-positive bacteria. Conversely, 1 % Chlorox and 1 % DMSO showed no significant antibacterial activity against gram-positive and gram-negative bacteria. Camellia sinensis mediated ZnO and Ag/ZnO nanoparticles showed antibacterial potential against S. aureus and E. coli suggesting that green route to synthesis of antibacterial nanoparticles can be an excellent strategy to develop eco-friendly disinfectant products HIGHLIGHTS Zinc oxide nanocomposites biosynthesis by Camellia sinensis at low pH, Antibacterial properties of ZnO nanoparticles and Ag/ZnO nanocomposites on Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P strains, Disinfection application. GRAPHICAL ABSTRACT
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Vitanov, Petko, Tatyana Ivanova, Hristosko Dikov, Penka Terziyska, Maxim Ganchev, Nikolay Petkov, Yordan Georgiev e Asen Asenov. "Effect of a Discontinuous Ag Layer on Optical and Electrical Properties of ZnO/Ag/ZnOStructures". Coatings 12, n. 9 (11 settembre 2022): 1324. http://dx.doi.org/10.3390/coatings12091324.
Testo completoAbstract (sommario):
ZnO/Ag/ZnO nanolaminate structures were deposited by consecutive RF sputtering at room temperature.The optical transparency, sheet resistance, and figure of merit are determined in relation to the deposition time of Ag and to the film thickness of the ZnO top layer. An improved transmittance has been found in the visible spectral range of the ZnO/Ag/ZnO structure compared to ZnO multilayers without Ag. High transmittance of 98% at 550 nm, sheet resistance of 8 Ω/sq, and figure of merit (FOM) of 111.01 × 10−3 Ω−1are achieved for an optimized ZnO/Ag/ZnO nanolaminate structure. It is suggested that the good optical and electrical properties are due to the deposition of the discontinuous Ag layer. The electrical metallic type conductivity is caused by planar located silver metal granules. The deposition of a discrete layer of Ag nano-granules is confirmed by atomic force microscopy (AFM) and cross-section high-resolution transmission electron microscopy (HRTEM) observations.
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Ivanova, Dobrina, George Tzvetkov e Nina Kaneva. "Degradation of Paracetamol in Distilled and Drinking Water via Ag/ZnO Photocatalysis under UV and Natural Sunlight". Water 15, n. 20 (11 ottobre 2023): 3549. http://dx.doi.org/10.3390/w15203549.
Testo completoAbstract (sommario):
The present study demonstrates the synthesis and application of Ag/ZnO powder films (thickness of 4 μm) as photocatalysts for natural sunlight and ultraviolet (UV, 315–400 nm) irradiation. The synthesis procedure is simple and eco-friendly, based on the photo-fixation of silver ions onto commercial ZnO powder via UV illumination for the first time. The photocatalytic efficiency of the newly developed films is evaluated through degradation of paracetamol in distilled and drinking water. Our experimental evidences show that the Ag/ZnO nanostructure films are more active than pristine ZnO films in the photodegradation process. Namely, the photocatalytic efficiency of the films modified with 10−2 M concentration of silver ions achieve the highest degradation (D) percentages for paracetamol in both types of water (Ddistilled = 80.97%, Ddrinking = 82.5%) under natural sunlight. Under UV exposure, the degradation percentages are slightly lower but still higher than those achieved by pure ZnO films (Ddistilled = 53.13%, Ddrinking = 61.87%). It is found that the photocatalytic activity grows in direct proportion to the concentration of Ag+ ions: ZnO < Ag 10−4/ZnO < Ag 10−3/ZnO < Ag 10−2/ZnO. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance and photoluminescence spectroscopy are used to characterize the as-prepared ZnO and Ag/ZnO nanostructures. The improved photocatalytic performance of the Ag/ZnO films is mostly attributed to the combination of excited electron transfer from ZnO to Ag and the inhibition of photogenerated electron–hole pair recombination. Furthermore, Ag/ZnO nanostructure films can retain their photocatalytic activity after three cycles of use, highlighting their potential practical application for the treatment of pharmaceutical wastewater in real-world scenarios where natural sunlight is often more readily available than artificial UV light.
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Lin, Yu-Hsuan, Chandrasekar Sivakumar, Babu Balraj, Gowtham Murugesan, Senthil Kumar Nagarajan e Mon-Shu Ho. "Ag-Decorated Vertically Aligned ZnO Nanorods for Non-Enzymatic Glucose Sensor Applications". Nanomaterials 13, n. 4 (17 febbraio 2023): 754. http://dx.doi.org/10.3390/nano13040754.
Testo completoAbstract (sommario):
The non-enzymatic glucose sensing response of pure and Ag-decorated vertically aligned ZnO nanorods grown on Si substrates was investigated. The simple low-temperature hydrothermal method was employed to synthesize the ZnO NRs on the Si substrates, and then Ag decoration was achieved by sputtering. The crystal structure and surface morphologies were characterized by X-ray diffraction, field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The Ag incorporation on the ZnO NR surfaces was confirmed using EDS mapping and spectra. Furthermore, the chemical states, the variation in oxygen vacancies, and the surface modifications of Ag@ZnO were investigated by XPS analysis. Both the glucose/ZnO/Si and glucose/Ag@ZnO/Si device structures were investigated for their non-enzymatic glucose sensing performances with different glucose concentrations. Based on EIS measurements and amperometric analysis, the Ag@ZnO-NR-based glucose sensor device exhibited a better sensing ability with excellent stability over time than pure ZnO NRs. The Ag@ZnO NR glucose sensor device recorded 2792 µA/(mM·cm2) sensitivity with a lowest detection limit of 1.29 µM.
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Li, Zhenjiang, Xiaoyan Fan, Alan Meng, Yunbo Zhang, Kaixing Zhu e Qingdang Li. "Porous Nanofibers Formed by Heterogeneous Growth of ZnO/Ag Particles and the Enhanced Photocatalysis". Journal of Nanoscience and Nanotechnology 19, n. 11 (1 novembre 2019): 7163–68. http://dx.doi.org/10.1166/jnn.2019.16518.
Testo completoAbstract (sommario):
Porous ZnO/Ag nanofibers with unique multi-interface contact structures have been synthesized by an electrospinning method. The composite nanofibers with the length of several hundred micrometers are composed of uniformly distributed ZnO and Ag nanoparticles in the size range 10~30 nm. Notably, a heterogeneous growth in the interface of ZnO and Ag particles occurs. The MO degradation rate of ZnO/Ag nanofibers with Ag content of 18 wt.% is 100% in 10 min under UV-vis irradiation and that of ZnO/Ag nanofibers with Ag content of 15 wt.% is 92% in 40 min under simulated day light, which is two times that of the pure ZnO. It is attributed to a special structure that improves the generation and separation efficiency of the photo-generated charges by the expansion of the absorption edges, the utilization efficiency of the surface plasmon resonance (SPR) oscillations of Ag, and the effective transferring of electrons from ZnO through the heterogeneous-growth interface. No obvious loss of the photocatalytic activity is observed after five cycles, indicating the excellent photostability of ZnO/Ag nanofibers. The work sheds light on the structure design of highperformance composite photocatalysts.
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Hoai, Pham Thi Thu, Nguyen Thi Mai Huong, Pham Thi Huong e Nguyen Minh Viet. "Improved the Light Adsorption and Separation of Charge Carriers to Boost Photocatalytic Conversion of CO2 by Using Silver Doped ZnO Photocatalyst". Catalysts 12, n. 10 (8 ottobre 2022): 1194. http://dx.doi.org/10.3390/catal12101194.
Testo completoAbstract (sommario):
This work developed a strategy to enhance the photocatalytic activity of ZnO by doping it with silver nanoparticles (Ag) to improve the light adsorption and separation of charge carriers, which further increases the conversion of CO2. The loading of Ag over ZnO (Ag-ZnO) was confirmed by characterization methods (SEM, XRD, and XPS), and the photocatalytic activities of Ag-ZnO were significantly enhanced. As the result, the production rates of CO and CH4 by doped Ag-ZnO were 9.8 and 2.4 µmol g−1 h−1, respectively. The ZnO that had the production rate of CO was 3.2 µmol g−1 h−1 and it is relatively low for the production of CH4 at around 0.56 µmol g−1 h−1. The doping of Ag over ZnO displayed a high conversion rate for both CO and CH4, which were 3 and 4.2 times higher than that of ZnO. The doped Ag-ZnO photocatalyst also had high stability up to 10 cycles with less than 11% loss in the production of CO and CH4. The improvement of photocatalytic activities of Ag-ZnO was due to the Ag doping, which enhanced the light adsorption (400–500 nm) and narrowed band gap energy (2.5 eV), preventing the charge carrier separation. This work brings an efficient photocatalyst for CO2 conversion in order to reduce carbon dioxide concentration as well as greenhouse gas emissions.
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Rodmuang, Sirirat, Raweewan Plairaharn, Kanokwan Teingtum, Suntree Sangjan e Orawan Chunhachart. "Effect of Ag/ZnO-Graphitic Carbon Nitride on Antimicrobial Activity under Visible Light". Key Engineering Materials 858 (agosto 2020): 116–21. http://dx.doi.org/10.4028/www.scientific.net/kem.858.116.
Testo completoAbstract (sommario):
Zinc oxide-graphitic carbon nitride (ZnO/g-C3N4) composites were synthesized by precipitation method in order to improve photocatalytic activity under visible light. To enhance antimicrobial activity, silver was added into zinc oxide-graphitic carbon nitride (Ag/ZnO/g-C3N4). Ultrastructures of the composite were analyzed by X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Photocatalytic activity of the composites was carried out by degradation of methylene blue solution as a function of contact time. The results revealed that ZnO/g-C3N4 was capable of dye degradation at 96.65%. Addition of Ag into ZnO/g-C3N4 resulted in increase of dye reduction rate. For antibacterial test, Ag/ZnO/g-C3N4 exhibited bactericidal activity against Pseudomonas aeruginosa and Bacillus cereus. For antifungal test, Ag/ZnO/g-C3N4 showed resistance to Aspergillusniger for 7 days. Ag/ZnO-g-C3N4 composite exhibited better photocatalytic and antimicrobial activities compare to ZnO and g-C3N4. These results indicate that precipitation method is a cheap, rapid and efficient method that can be used to synthesize Ag/ZnO-g-C3N4 composites. For further studies, applications of this Ag/ZnO-g-C3N4 composites in microbiological and agricultural fields will be carried out.
34
Min, Jia Hua, Xiao Yan Liang, Bin Wang, Yue Zhao, Yun Guo e Lin Jun Wang. "Characterization of Ag Doped P-Type ZnO Thin Films Prepared by Electrostatic-Enhanced Ultrasonic Spray Pyrolysis". Advanced Materials Research 299-300 (luglio 2011): 436–39. http://dx.doi.org/10.4028/www.scientific.net/amr.299-300.436.
Testo completoAbstract (sommario):
In this paper, the structure, electrical and optical properties and stabilities of Ag doped p-type ZnO thin films, prepared by electrostatic-enhanced ultrasonic spray pyrolysis were investigated. XRD and Hall data analyses indicated that the resistivity of 4at. % Ag doped p-type ZnO was low, without Ag2O phase separation. The optical transmission spectra illustrated that optical band gaps decreases with the gradual increase of Ag dopant. Moreover, ZnO: Ag films placed for 10 days still showed p-type, but the optical transmittance decreased, suggesting that AgZn in the ZnO: Ag thin films captured electrons to generate Agi, which reunited to be Ag nano-particles and decreased the optical transmittance of ZnO: Ag.
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Jiménez, Adriana Berenice Pérez, Carlos Alberto Huerta Aguilar, Jorge Manuel Vázquez Ramos e Pandiyan Thangarasu. "Synergistic Antibacterial Activity of Nanohybrid Materials ZnO–Ag and ZnO–Au: Synthesis, Characterization, and Comparative Analysis of Undoped and Doped ZnO Nanoparticles". Australian Journal of Chemistry 68, n. 2 (2015): 288. http://dx.doi.org/10.1071/ch14123.
Testo completoAbstract (sommario):
ZnO nanoparticles (NPs) were prepared using the hydrothermal method, and then doped with Ag or Au NPs, yielding ZnO NPs, ZnO–Ag NPs, and ZnO–Au NPs, which were characterized by transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The synthesized nanomaterials were analyzed for their antibacterial properties against bacterial strains (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella typhi) by qualitative and quantitative assays. Minimal inhibitory concentration (MIC) results show that growth control is more effective for Gram-positive bacteria than for Gram-negative bacteria. Although ZnO NPs and Ag NPs are antibacterial agents, the lowest bacterial growth was observed for ZnO–Ag NPs, showing that the doped Ag NPs greatly facilitate the interaction between the microbial cells and the NP surface. Though the same antibacterial effect was expected for ZnO–Au NPs, the inhibition activity was very close to that of ZnO NPs. The order of bacterial cell growth inhibition was ZnO–Ag NPs >> ZnO–Au NPs ~ ZnO NPs >> ZnO powder. We also analyzed the morphology of bacterial cells treated with NPs by scanning electron microscopy.
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Wang, Ying Lian, e Jun Yao Ye. "Photocatalytic Properties of ZnO and Ag Doped ZnO Thin Films". Applied Mechanics and Materials 685 (ottobre 2014): 3–6. http://dx.doi.org/10.4028/www.scientific.net/amm.685.3.
Testo completoAbstract (sommario):
Pure ZnO thin films and Ag doped ZnO thin films were prepared on quartz substrates by sol-gel process. Structural features and UV absorption spectrum have been studied by XRD and UV-Vis-Nir scanning spectrophotometer. Taking phenol as pollutants, further study of the effect of different annealing temperature and Ag dopant amount of ZnO films on photocatalytic properties was carried out. The results showed that, the optimal annealing temperature on photocatalytic degradation of phenol in this experiment was 300 °C, the best molar ratio of ZnO and Ag was 30:1, which was better than pure ZnO film greatly. Excellent adhesion, recyclable and efficient degradation Ag doped ZnO thin films were found in this experiment.
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Tan, Hong Lin, Cong Ying Jia, Xiao Xu Ge e Chao Xiang. "First-Principles Conductance Calculations of Ag-Al Co-Doped ZnO". Advanced Materials Research 468-471 (febbraio 2012): 1726–31. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.1726.
Testo completoAbstract (sommario):
Based on Density Functional Theory (DFT) first-principles plane-wave ultra-soft pseudo-potential method, we calculated the electronic structure of wurtzite ZnO, Ag-doped ZnO and Ag-Al co-doped ZnO. And we anglicized of energy band structure, electron density of states of Ag-doped and Ag- Al co-doped ZnO crystal. The results indicated: Ag-doped ZnO introduced the deep accepter level in the energy gap, carrier (hole) located near the top of the valence band. And when we add active donor Al to the Ag-Al doped ZnO, the main level moved to low-energy, forming a shallow acceptor level. Meanwhile, the acceptor level got wider, non-localized features got significantly, improving the doping concentration and stability of the system.
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Ding, Yan Li, Yue Zhao e Lin Jun Wang. "The Influence of Oblique Deposited Angle on Metal Enhanced Fluorescence Property of Ag and Ag/ZnO Core-Shell Structure". Advanced Materials Research 905 (aprile 2014): 32–36. http://dx.doi.org/10.4028/www.scientific.net/amr.905.32.
Testo completoAbstract (sommario):
In this paper, the Ag nanoparticles were successfully prepared by oblique evaporation method, and then the ZnO shell layer was coated on surface of silver particles using wet chemical method. Hereafter, the structure, the morphology and the metal enhanced fluorescence (MEF) property of the Ag and the Ag/ZnO core-shell particles were studied by XRD,SEM,TEM and fluorescence (FL) spectra. From the XRD patterns and the SEM,TEM images, the Ag nanocolumn and the Ag/ZnO composite were successful obtained. Furthermore, the density of Ag nanocolumnar structure decreased with the increase of depositing angle. This phenomenon could be attributed to the surface diffusion function and the shading effect, As the result of the FL spectra, the MEF performance of the Ag/ZnO composite was more prominent than that of Ag nanocolumn, due to the quenching effect. Moreover, the MEF performance of the Ag/ZnO composite depended on the deposited angle, firstly increasing and then decreasing with the tilt angle of Ag/ZnO core-shell structure. The mechanism of fluorescence enhancement would be due to the surface plasmon resonance of Ag surface and the change in photonic mode density and/or reduction in self-quenching of fluorophores for ZnO nanostructure.
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Praveena, Ravipati, V. Sravani Sameera, Md Ahamad Mohiddon e M. Ghanashyam Krishna. "Surface plasmon resonance, photoluminescence and surface enhanced Raman scattering behaviour of Ag/ZnO, ZnO/Ag and ZnO/Ag/ZnO thin films". Physica B: Condensed Matter 555 (febbraio 2019): 118–24. http://dx.doi.org/10.1016/j.physb.2018.11.035.
Testo completo
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Zang, Ya Shu, Jun Yin, Jing Li e Jun Yong Kang. "The Enhanced Raman Scattering from Ag Nanoball/ZnO Hollow Nanosphere Arrays Fabricated by Laser-Induced Annealing". Key Engineering Materials 609-610 (aprile 2014): 779–83. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.779.
Testo completoAbstract (sommario):
In this work, a facile method was presented to produce Ag nanoball (NB)/ZnO hollow nanosphere (HNS) hybrid structure. Large scale, two-dimensional (2D) ZnO HNS arrays were fabricated on sapphire substrates using the polystyrene (PS) nanospheres as the template. Ag film were deposited on ZnO HNS arrays by radio frequency (RF) magnetron sputtering and then aggregated into Ag NBs on the top of ZnO HNS by the laser irradiation treatment. The size and distribution of Ag NB arrays were controlled by employing different ZnO HNS supporting structure templates. The scanning electron microscopy (SEM) was applied to visually study the evolution process of Ag NB/ZnO NHS arrays. X-ray diffraction (XRD) was carried out to characterize crystal structures of the samples. Obvious surface enhanced Raman (SERS) signals were observed from the Ag NB/ZnO NHS nanocomposite structure compared with that in the ZnO HNS structure by using the R6G as the testing agent. Theoretical simulation results demonstrate that the Raman enhancement originates from the significant enhanced local electromagnetic field induced by the surface plasmon resonance (SPR) of Ag NBs.
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Zulaikha Umbaidilah, Siti, Nur Amierah M. Asib, Nurul Afaah Abdullah, Mohamad Rusop e Zuraidah Khusaimi. "Influence of Different Atomic Percentage of Silver Doped Nano Zinc Oxide on Titanium Dioxide Seeded Substrate". International Journal of Engineering & Technology 7, n. 4.14 (24 dicembre 2019): 544. http://dx.doi.org/10.14419/ijet.v7i4.14.27787.
Testo completoAbstract (sommario):
Non-doped ZnO/TiO2 and Silver (Ag) doped ZnO/TiO2 nanostructures thin film were successfully synthesized on glass substrate by using sol-gel spin coating technique for deposition of TiO2 seed layer and solution immersion method for growth of Ag-doped ZnO/TiO2 nanostructure. Different atomic percentage (at%) which is 0.5, 1.0, 1.5, 2.0 and 2.5 at% of Ag doped were added in 0.4 M of Zn2+ solution. The EDX result revealed that the sample was composed of Zn, O and Ag elements which confirmed the existence of Ag element in the sample. The XRD spectra shows that the intensity of the (002) peak of 0.5 at % Ag-doped ZnO/TiO2 was the highest compared to other samples and all the samples revealed polycrystalline structure belonging to the ZnO hexagonal wurtzite type. The UV-vis absorbance also indicates that 0.5 at% Ag-doped ZnO/TiO2 has the highest absorbance and non-doped ZnO/TiO2 displayed the lowest absorbance compared to the other sample. Thus, 0.5 at% of Ag-doped ZnO/TiO2 is the best candidate for optical application due to the higher intensity and greater absorbance.
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Chang, Tung-Hao, Yun-Ting Liu, Yu-Cheng Chang e An-Ya Lo. "Fabrication of Three-Dimensional ZnO: Ga@ITO@Ag SERS-Active Substrate for Sensitive and Repeatable Detectability". Nanomaterials 13, n. 1 (29 dicembre 2022): 163. http://dx.doi.org/10.3390/nano13010163.
Testo completoAbstract (sommario):
Vertically aligned ZnO: Ga nanotowers can be directly synthesized on a glass substrate with a ZnO seed film via the chemical bath method. A novel heterostructure of ZnO: Ga@ITO@Ag nanotowers was subsequently deposited in the ITO layer and Ag nanoparticles via the facile two-step ion-sputtering processes on the ZnO: Ga nanotowers. The appropriate ion-sputtering times of the ITO layer and Ag nanoparticles can benefit the fabrication of ZnO: Ga@ITO@Ag nanotowers with higher surface-enhanced Raman scattering (SERS) enhancement in detecting rhodamine 6G (R6G) molecules. Compared with ZnO: Ga@Ag nanotowers, ZnO: Ga@ITO@Ag nanotowers exhibited a high SERS enhancement factor of 2.25 × 108 and a lower detection limit (10−14 M) for detecting R6G molecules. In addition, the ITO layer used as an intermediate layer between ZnO: Ga nanotowers and Ag nanoparticles can improve SERS enhancement, sensitivity, uniformity, reusability, detection limit, and stability for detecting amoxicillin molecules. This phenomenon shall be ascribed to the ITO layer exhibiting a synergistic Raman enhancement effect through interfacial charge transfer for enhancing SERS activity. As a result, ZnO: Ga@ITO@Ag nanotowers can construct a three-dimensional SERS substrate for potential applications in environmentally friendly and cost-effective chemical or drug detection.
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Mohammed Nemma, Noorullah, e Zainab Sabeeh Sadeq. "Eco-Friendly Synthesis of Ag-ZnO Nanocomposite Using Aloe-vera, Hibiscus Sabdariffa Plants and Their Antibacterial and Anti-fungi Activities". Iraqi Journal of Physics 21, n. 4 (1 dicembre 2023): 14–23. http://dx.doi.org/10.30723/ijp.v21i4.1136.
Testo completoAbstract (sommario):
The current study used extracts from the aloe vera (AV) plant and the hibiscus sabdariffa flower to make Ag-ZnO nanoparticles (NPs) and Ag-ZnO nanocomposites (NCs). Ag/ZnO NCs were compared to Ag NPs and ZnO NPs. They exhibited unique properties against bacteria and fungi that aren't present in either of the individual parts. The Ag-ZnO NCs from AV showed the best performance against E. coli, with an inhibition zone of up to 27 mm, compared to the other samples. The maximum absorbance peaks were observed at 431 nm and 410 nm for Ag NPs, at 374 nm and 377 nm for ZnO NPs and at 384 nm and 391 nm for Ag-ZnO NCs using AV leaf extract and hibiscus sabdariffa flower extract, respectively. Using field emission-scanning electron microscopes (FE-SEM), the green synthesis of the shown NPs and NCs was found. The Ag NPs particle sizes ranged from 16.99 to 26.39 nm for AV and from 13.11 to 29.50 nm for hibiscus sabdariffa flowers, respectively. The particle size of ZnO NPs ranged from 23.04 to 32.58 nm and from 37.99 to 79.59 nm via AV and hibiscus sabdariffa flowers, respectively. Finally, the particle size of the Ag/ZnO nanocomposite ranged from 22.39–40.05 nm and from 59.73–87.05 nm via the AV and hibiscus sabdariffa flowers, respectively.
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Sun, Yao, e Hong Wang. "Influence of Deposition Mode in Reactively Sputtered ZnO Underlayer on Thermal Stability of Thin Silver Films". Materials Science Forum 852 (aprile 2016): 1018–24. http://dx.doi.org/10.4028/www.scientific.net/msf.852.1018.
Testo completoAbstract (sommario):
The influence of deposition mode of the ZnO underlayer on the thermal stability of 20nm thick Ag films in the ZnO/Ag/SiN multilayer stacks were investigated. ZnO films were deposited by reactive sputtering of Zn target under different O2 flows corresponding to both transition and oxide modes. The films were characterized by sheet resistance, X-ray diffraction and SEM imaging before and after thermal annealing at 350°C, 400°C and 500°C, respectively. The results show that ZnO underlayer improves the thermal stability of the Ag films significantly. The ZnO deposition mode has huge impact on the Ag film on top of it. Compared with ZnO deposited in transition mode, ZnO deposited in oxide mode can induce more crystalline Ag film with stronger (111) preferred orientation, which is more thermally stable. For ZnO deposition in oxide mode, an optimal oxygen flow is identified to result in the most thermally stable Ag layer.
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Копач, В. Р., Е. С. Клепикова, Н. П. Клочко, Г. С. Хрипунов, В. Е. Корсун, В. Н. Любов, М. В. Кириченко e А. В. Копач. "Структура и свойства электроосажденных в импульсном режиме наноструктурированных массивов ZnO и нанокомпозитов ZnO/Ag на их основе". Физика и техника полупроводников 51, n. 3 (2017): 348. http://dx.doi.org/10.21883/ftp.2017.03.44206.8303.
Testo completoAbstract (sommario):
Исследованы структура, морфология поверхности и оптические свойства электроосажденных в импульсном режиме наноструктурированных массивов ZnO, а также осажденных из коллоидных растворов наночастиц Ag и нанокомпозитов ZnO/Ag на их основе. По результатам исследований вольт-амперных и вольт-фарадных характеристик проведен анализ электронных и электрических параметров массивов ZnO и нанокомпозитов ZnO/Ag. Определены оптимальные режимы изготовления стабильных и высокочувствительных по отношению к ультрафиолетовому излучению гетероструктур ZnO/Ag в качестве перспективных материалов фотодетекторов, газовых датчиков и фотокатализаторов. DOI: 10.21883/FTP.2017.03.44206.8303
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Masa, Abdulhakim, Nureeyah Jehsoh, Sawitree Dueramae e Nabil Hayeemasae. "Boosting the Antibacterial Performance of Natural Rubber Latex Foam by Introducing Silver-Doped Zinc Oxide". Polymers 15, n. 4 (19 febbraio 2023): 1040. http://dx.doi.org/10.3390/polym15041040.
Testo completoAbstract (sommario):
Natural rubber (NR) latex foam is one of the rubber products that are increasingly in demand in the market. This is simply because of its lightweight, good thermal insulation, and resilience. The applications of NR latex foam are mostly for pillows and mattresses. This has resulted in these products requiring antibacterial performance which is very important for the safety of the end-users. In this study, the antibacterial NR latex foam was prepared by incorporating the silver-doped zinc oxide (Ag-doped ZnO) into the NR latex foam. Ag-doped ZnO was prepared by microwave-assisted method and then characterized through morphological characteristics and X-ray diffraction (XRD). The content of Ag doped onto ZnO was designed by varying the AgNO3 content at 15 wt%, 50 wt%, and 100 wt% of ZnO. The results confirmed that the Ag was successfully doped onto ZnO. The silver particles were found to be in the 40–50 nm range, where the size of ZnO ranges between 300 and 400 nm, and the Ag attached to the ZnO particles. The XRD patterns of Ag-doped ZnO correspond to planes of hexagonal wurtzite ZnO structure and cubic metallic Ag. This Ag-doped ZnO was further added to NR latex foam. It was observed that Ag-doped ZnO did not affect the physical properties of the NR latex foam. However, it is clear that both the inhibition zone and percent reduction of bacteria (e.g., E. coli and S. aureus) were enhanced by the addition of Ag-doped ZnO. It showed a decrease in the amount of cell growth over contact time. The content of 100 wt% AgNO3 could reduce E. coli and S. aureus up to 64.72% and 58.90%, respectively, when samples were maintained for 24 h. This study provides a scientific understanding of how Ag-doped ZnO could facilitate the development of eventual rubber foam products based on the respective results.
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Alzahrani, Elham A., Arshid Nabi, Majid Rasool Kamli, Soha M. Albukhari, Shaeel Ahmed Althabaiti, Sami A. Al-Harbi, Imran Khan e Maqsood Ahmad Malik. "Facile Green Synthesis of ZnO NPs and Plasmonic Ag-Supported ZnO Nanocomposite for Photocatalytic Degradation of Methylene Blue". Water 15, n. 3 (17 gennaio 2023): 384. http://dx.doi.org/10.3390/w15030384.
Testo completoAbstract (sommario):
Removing organic pollutants, textile dyes, and pharmaceutical wastes from the water bodies has become an essential requirement for a safe environment. Therefore, the present study aimed to prepare semiconductor zinc oxide nanoparticles (ZnO NPs) and plasmonic Ag-supported ZnO nanocomposite (ZnO–Ag) using an environmentally friendly bio-approach as an alternative to hazardous synthesis approaches. ZnO NPs and ZnO–Ag nanocomposite were characterized by using UV–Vis diffuse reflectance spectroscopy (UV–DRS) (the Ag-supported ZnO nanocomposite exhibited an absorption band between 450–550 nm, attributed to the Ag NPs surface plasmon resonance (SPR)), Photoluminescence (PL) spectral investigation, which revealed the PL emission intensity of ZnO–Ag NPs was lower than pure ZnO NPs, describing an extended electron-hole pair (e--h+) lifespan of photogenerated charge carriers, Fourier transform infrared spectroscopy (FTIR), FT-Raman, and X-ray diffraction (XRD) analyses were deduced. In addition, energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) were performed and further ascertained the successful biosynthesis and thermally stable ZnO Nps and ZnO–Ag nanocomposite. The as-prepared ZnO–Ag nanocomposite displayed increased photocatalytic characteristics due to the decline in the bandgap energy from 3.02 eV (ZnO NPs) to 2.90 eV (ZnO–Ag nanocomposite). The photocatalytic activity of the developed nanocomposite for the degradation of methylene blue (MB) dye, a primary textile industry released water-pollutant, was conducted under UV light irradiation. Meanwhile, the maximum % degradation of MB dye molecules was attained by 98.0 % after 60 min exposure of UV-light irradiation. Increased photocatalytic activity of ZnO–Ag nanocomposites and a faster rate of MB degradation were achieved by the deposition of plasmonic Ag NPs and the surface plasmon resonance (SPR) effect possessed by Ag NPs. The primary oxidative route that resulted in MB degradation was the production of hydroxyl radicals (OH•). The SPR effect of the photocatalyst induced the synergistic enhancement of the optical response and separation of the photo-induced charge carriers. The combined study gives comprehensive information and directions for future research on noble metal-modified nanocatalysts for direct applications in the photocatalytic degradation of textile and organic wastes in water.
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Pradila, Mutia Hasmi, Jesi Pebralia e Frastica Deswardani. "Synthesis and Characterization of ZnO/Ag Thin Films as Peat Water Degraders in East Tanjung Jabung Regency, Jambi". Journal BiGME 2, n. 1 (31 marzo 2022): 1–7. http://dx.doi.org/10.22437/bigme.v2i1.31178.
Testo completoAbstract (sommario):
Telah dilakukan sintesis dan karakterisasi lapisan tipis ZnO/Ag dengan teknik doctor blade sebagai aplikasi fotokatalis, pendegradasi air Gambut di Kabupaten Tanjung Jabung Timur. Bahan utama dalam pembuatan lapisan tipis adalah Zinc Acetat merck dan AgNO3 sebagai bahan utama Ag. Lapisan tipis di buat dengan variasi doping Ag 0%, 2%, 5%, dan 7%. Sintesis ZnO/Ag menggunakan metode sol-gel dan pembuatan lapisan tipis dengan teknik doctor blade. Hasil karakterisasi UV-Vis menunjukan nilai band gap ZnO/Ag secara berturut-turut yaitu sebesar 3,25 eV, 3,00 eV, 2,65 eV, 2,85 eV. Artinya band gap energy cenderung menurun seiring bertambahnya doping yang diberikan. Hasil analisis data XRD menunjukan ZnO/Ag 0%, 5% dan 7% berbentuk Hexagonal dengan ukuran Kristal berturut-turut sebesar 49,99 nm, 41,66 nm, dan 41,66 nm. Kemampuan degredasi ZnO/Ag terhadap air gambut terbaik ialah ZnO/Ag variasi doping 5% dengan persentasi degredasinya yang dilakukan dibawah lampu UV-Vis sebesar 92,9 % untuk uji parameter TDS, pH 6,7 dan uji parameter TSS 35,5%
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Pham, Thi Anh Tuyet, Van Anh Tran, Van Duong Le, Minh Viet Nguyen, Duc Duc Truong, Xuan Truong Do e Anh-Tuan Vu. "Facile Preparation of ZnO Nanoparticles and Ag/ZnO Nanocomposite and Their Photocatalytic Activities under Visible Light". International Journal of Photoenergy 2020 (22 ottobre 2020): 1–14. http://dx.doi.org/10.1155/2020/8897667.
Testo completoAbstract (sommario):
Zinc oxide (ZnO) has been known as an excellent photocatalyst for the degradation of a variety of organic pollutants under UV irradiation. This work describes a synthesis of ZnO nanoparticles via a facile precipitation method, and Ag was doped into Ag/ZnO nanocomposite to improve the photocatalytic degradation of BPA under visible light irradiation. The obtained ZnO nanoparticles were 20 nm in size and had a relatively high surface area and pore volume, 26.2 m2/g and 0.48 cm3/g, respectively. The deposition of Ag led to a decrease in the surface area, pore volume, and band gap energy ( E g ) of ZnO nanoparticles. However, the photocatalytic activity of Ag/ZnO composite in the case increased. The performance of ZnO was compared with Ag/ZnO composites at the different molar ratios, and the kinetic reaction of BPA in these catalysts was investigated by the first-order kinetic model. The sample of Ag/ZnO-10 composite had the highest catalytic activity and showed the degradation efficiency, reaction rate, and degradation capacity of 100% in 120 min, 0.014 min-1, and 40 mg/g, respectively. In comparison, the effects of Ag/ZnO molar ratio, catalyst dosage, solution pH, and concentration of BPA on photocatalytic degradation were investigated. Additionally, the photocatalytic performance of Ag/ZnO-10 composite was evaluated by the degradation of other persistent organic compounds such as phenol, tartrazine, and methylene blue and compared to other catalysts in literature.
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Huang, Jung Jie, Ching Hsun Chao, Chao Nan Chen, Chun Fa Hsu e Ming Wei Tsai. "Size Effect of Silver Nanoparticle Melted into ZnO Nanorods for Photocatalytic Activity". Applied Mechanics and Materials 284-287 (gennaio 2013): 367–74. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.367.
Testo completoAbstract (sommario):
Ag/ZnO nanorod structure was synthesized by using the hydrothermal method to grow ZnO nanorods and melted silver nonoparticles into ZnO nanorods by thermal annealing process in vacuum at 700 oC. The photocatalytic activity for methylene blue decolorization is enhanced by silver nanoparticles melted into a ZnO nanorod structure owing to the formation of Schottky barrier near the Ag/ZnO interface prolongs the recombination of electron-hole pairs effectively. The size effect of silver nanoparticles in the Ag/ZnO nanorod structure for photocatalytic activity was discussed which was changed from 12 to 34 nm. The smaller silver nanoparticle size sample shows better decolorization efficiency of methylene blue solution owing to the higher surface area of Ag/ZnO nanoroad. Ag/ZnO nanorod films have been characterized by X-ray diffraction (XRD), UV-vis spectroscopy, field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The dye decolorization significantly increased from 69 to 99 % after UV light irradiation for 8 hr by the optimum Ag/ZnO nanorod film.