Journal articles: 'Metal doping'

1

Wang, Ting, Yan Dong Mao, Fang Peng Tang, Jun Xing, and Li Guang Wu. "Crystallization and Photocatalytic-Activity of TiO₂ Doped with Metal Ions Prepared by Adsorption Phase Synthesis." Advanced Materials Research 624 (December 2012): 194–99. http://dx.doi.org/10.4028/www.scientific.net/amr.624.194.

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TiO2 photocatalysts doped with different metal ions were prepared by adsorption phase synthesis. The influence of different dopant metal ions with various concentrations on the crystallization of TiO2 was ex-plored by XRD. Then photodegradation experiments of methyl-orange were employed to evaluate the activity of these photocatalysts. The results indicated that the crystallization of TiO2 was restricted after doping, due to replacement of Ti4+ in TiO2 lattice structure by other metal ions. And the restriction became stronger with radius and concentration of doping ions increasing. There was an optimum dopant concentration appeared during preparation of TiO2 doped with Cd2+ and Fe3+. When dopant concentration was less or more than this optimum value, the photocatalytic activity of TiO2 doped with metal ions was lower than that of TiO2 without doping. Since radius of Fe3+ was close to Ti4+, the influence of Fe3+ dopant concentration on crystallization and activity of TiO2 was more obvious than that of Cd2+ doping.

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Hua, L., and L. Zhang. "Effect of In, Bi, Zn Binary-Metal Dopings in Sn-0.7Cu Solder on its Electrochemical Corrosion Charateristics in 3 wt.% NaCl Solution." Advanced Materials Research 548 (July 2012): 286–92. http://dx.doi.org/10.4028/www.scientific.net/amr.548.286.

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Effect of In, Zn, Bi binary-metal dopings in Sn-0.7Cu (SC) solder on the electrochemical corrosion characteristics of SC solder were conducted, the potentiodynamic polarization test coupled with SEM analyses had been widely used to study the corrosion properties of alloy materials. The results showed that when both In-Zn binary-metal doping was increased, the corrosive current density (Icorr) increased, which proved that anti-corrosion capacities of Sn-0.7Cu solder decreased with In-Zn doping increasing, the affected order was Zn>In. When both In-Bi binary-metal doping percent were increased, the corrosive current density (Icorr) decreased, the affected order was In>Bi. When both Zn-Bi binary-metal doping percent were increased, the Icorr increased, the affected order was Zn>Bi. There was collaborated function on SC solder for the three metals. The synthesized result showed that the sequence of In, Bi, Zn affecting on corrosion of SC solder was that Zn>In>Bi, which provide a support data to improve soldering reliability in electronic packagings.

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Rojanasuwan, Sunit, Pakorn Prajuabwan, Annop Chanhom, Anuchit Jaruvanawat, Adirek Rangkasikorn, and Jiti Nukeaw. "The Effect of the Central Metal Atom on the Structural Phase Transition of Indium Doped Metal Phthalocyanine." Advanced Materials Research 717 (July 2013): 146–52. http://dx.doi.org/10.4028/www.scientific.net/amr.717.146.

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We investigate the effect of central metal atom on the phthalocyanine (Pc) molecular crystals as intercalated with indium. As dopant, indium has physical interaction with some atom in the ring of Pc molecule and there is charge transfer between indium atom and Pc ring atom. Since In-doped Pc is a hole doping which increase positive charge carriers and the HOMO of ZnPc, CuPc, NiPc and MgPc are localized on the phthalocyanine ring, then, the central metal atom e.g. Zn, Cu, Ni and Mg are not directly involved with the charge transfer between indium dopant and their Pc molecule. The structural phase transition from α phase to β phase of ZnPc upon doping with indium is another evidence for the existing of charge transfer between dopant atom and matrix Pc molecule. A comparative experiment of optical absorption spectrum of each metal Pc reveals that the central metal atom will affect the forming of crystal structure whether will be α phase or β phase as intercalated with indium.

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Zhang, Siyuan, Hsun Jen Chuang, Son T. Le, Curt A. Richter, Kathleen M. McCreary, Berend T. Jonker, Angela R. Hight Walker, and Christina A. Hacker. "Control of the Schottky barrier height in monolayer WS₂ FETs using molecular doping." AIP Advances 12, no. 8 (August 1, 2022): 085222. http://dx.doi.org/10.1063/5.0101033.

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Developing controllable doping processes for two-dimensional (2D) semiconductors is critical to developing next-generation electronic and optoelectronic devices. Understanding the nature of the contacts is an essential step in realizing efficient charge injection in transition metal dichalcogenides. In this study, post-growth n-doping of chemical vapor deposition grown monolayer (1 L) WS2 is achieved through molecular reductant solution treatment. The doping level can be effectively controlled by the treatment time and dopant solution concentrations. The doped WS2 field-effect transistors showed profound threshold voltage shifts and tunable channel currents. This molecular n-doping technique is beneficial for the selective area doping needed for electrical contacts and reduces the contact resistance ( Rc) in 1 L WS2 by more than two orders of magnitude. The significant reduction of Rc is attributed to the high electron-doping density achieved in WS2, which leads to a significant reduction of the Schottky barrier height. The dependence of mobility on temperature indicates clear evidence of the strong suppression of charge-impurity scattering after doping. High levels of doping allow the observation of a metal–insulator transition in monolayer WS2 due to strong electron–electron interactions. This doping technique provides a viable route for tailoring the electrical properties and improving the contacts in transition metal dichalcogenides, paving the way for high-performance 2D nanoelectronic devices.

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Carey, J. J., and M. Nolan. "Cation doping size effect for methane activation on alkaline earth metal doping of the CeO2 (111) surface." Catalysis Science & Technology 6, no. 10 (2016): 3544–58. http://dx.doi.org/10.1039/c5cy01787d.

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Mogal, Sajid I., Manish Mishra, Vimal G. Gandhi, and Rajesh J. Tayade. "Metal Doped Titanium Dioxide: Synthesis and Effect of Metal Ions on Physico-Chemical and Photocatalytic Properties." Materials Science Forum 734 (December 2012): 364–78. http://dx.doi.org/10.4028/www.scientific.net/msf.734.364.

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Titanium dioxide (Titania; TiO2) is one of the most widely used metal oxide semiconductor in the field of photocatalysis for removal of pollutants. It has been noted that titanium dioxide is a research friendly material as its physico-chemical and catalytic properties can be easily altered as per specific application. Since many years, researchers have tried to modify the properties of titanium dioxide by means of doping with metals and non-metals to improve its performance for photocatalytic degradation (PCD) applications. The doping of various metal ions like Ag, Ni, Co, Au, Cu, V, Ru, Fe, La, Pt, Cr, Ce, etc. in titanium dioxide have been found to be influencing the band gap, surface area, particle size, thermal property, etc. and therefore the photocatalytic activity in PCD. Moreover, photocatalytic activity of doped titanium dioxide has been observed in visible light range (i.e., at wavelength >400 nm). In this review, different synthesis route for doping of metal ions in titanium dioxide have been emphasised. The effect of metal dopant on the structural, textural and photocatalytic properties of titanium dioxide has been reviewed.

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Periyat, Pradeepan, Binu Naufal, and Sanjay Gopal Ullattil. "A Review on High Temperature Stable Anatase TiO₂ Photocatalysts." Materials Science Forum 855 (May 2016): 78–93. http://dx.doi.org/10.4028/www.scientific.net/msf.855.78.

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This review focuses on the recent developments of high temperature stable anatase TiO2 photocatalyst. Eventhough TiO2 exists in different forms anatase, rutile and brookite, anatase phase stabilization is often the key to obtain the highest photocatalytic performance for TiO2, particularly for the use as an antibacterial and self-cleaning coatings in high temperature processed ceramics. Different methods available for the anatase stabilization in literature are critically reviewed and emphasis is placed on relatively recent developments. Currently available methods of anatase stabilizations are classified in to four categories viz (i) doping with metal ions (ii) doping with non-metal ions (iii) co-doping with metal and non-metal ions and (iv) dopant free stabilization by oxygen richness. Further to this, the application of these high temperature stabilized anatase TiO2 photocatalyst on various ceramics substrates such as tile, glass and sanitary wares as self-cleaning and antibacterial coatings are also been briefly discussed.

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8

Li, Bin, Yihan Zhang, Yang Liu, Yiwen Ren, Xiaoting Zhu, Lingjie Sun, Xiaotao Zhang, Fangxu Yang, Rongjin Li, and Wenping Hu. "Highly Efficient Contact Doping for High-Performance Organic UV-Sensitive Phototransistors." Crystals 12, no. 5 (May 2, 2022): 651. http://dx.doi.org/10.3390/cryst12050651.

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Organic ultraviolet (UV) phototransistors are promising for diverse applications. However, wide-bandgap organic semiconductors (OSCs) with intense UV absorption tend to exhibit large contact resistance (Rc) because of an energy-level mismatch with metal electrodes. Herein, we discovered that the molecular dopant of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) was more efficient than the transition metal oxide dopant of MoO3 in doping a wide-bandgap OSC, although the former showed smaller electron affinity (EA). By efficient contact doping, a low Rc of 889 Ω·cm and a high mobility of 13.89 cm2V−1s−1 were achieved. As a result, UV-sensitive phototransistors showed high photosensitivity and responsivity.

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9

Dzhumanov, S. "METAL-INSULATOR TRANSITIONS IN DOPED La-BASED SUPER CONDUCTORS WITH SMALL-RADIUS DOPANTS." Eurasian Physical Technical Journal 19, no. 1 (39) (March 28, 2022): 15–19. http://dx.doi.org/10.31489/2022no1/15-19.

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n this work, we study the possibility of realizing two distinct mechanisms of metal-insulator transitions in hole-doped cuprates induced by the localization of charge carriers near the small-radius impurities and in a deformable lattice (i.e. in the absence of impurities). The purpose of this research is to determine the criteria (i.e. conditions) for the existence of the localized states of hole carriers and solve the problem of metal-insulator transitions in La-based cuprates. The advantage of La-based cuprate versus other types of cuprates is that two distinct metal-insulator transitions in La-based cuprates driven by the strong carrier-impurity-phonon and carrier-phonon interactions occur simultaneously in a wider doping range from the lightly doped to heavily doping regime. We show that at very low doping, the separate levels of hole carriers localized near impurities and in a deformable lattice are formed in the charge-transfer gap of the cuprates. As the doping level increases towards underdoped region, the energy levels of such charge carriers start to form energy bands which gradually broaden with increasing doping. We propose a new two-carrier cuprate superconductor model for studying two distinct metal-insulator transitions occurring simultaneouslyin hole-doped La-based cuprate compounds. We demonstrate that when hole carriers reside in impurity and polaron bands, these metal-insulator transitions in La-based superconductors with small-radius dopants occur accordingly in a wide doping range and relatively lower doping levels.

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Han, Juan, Xu Wu, Julia Xiaojun Zhao, and David T. Pierce. "An Unprecedented Metal Distribution in Silica Nanoparticles Determined by Single-Particle Inductively Coupled Plasma Mass Spectrometry." Nanomaterials 14, no. 7 (April 6, 2024): 637. http://dx.doi.org/10.3390/nano14070637.

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Metal-containing nanoparticles are now common in applications ranging from catalysts to biomarkers. However, little research has focused on per-particle metal content in multicomponent nanoparticles. In this work, we used single-particle inductively coupled plasma mass spectrometry (ICP-MS) to determine the per-particle metal content of silica nanoparticles doped with tris(2,2′-bipyridyl)ruthenium(II). Monodispersed silica nanoparticles with varied Ru doping levels were prepared using a water-in-oil microemulsion method. These nanoparticles were characterized using common bulk-sample methods such as absorbance spectroscopy and conventional ICP-MS, and also with single-particle ICP-MS. The results showed that averaged concentrations of metal dopant measured per-particle by single-particle ICP-MS were consistent with the bulk-sample methods over a wide range of dopant levels. However, the per-particle amount of metal varied greatly and did not adhere to the usual Gaussian distribution encountered with one-component nanoparticles, such as gold or silver. Instead, the amount of metal dopant per silica particle showed an unexpected geometric distribution regardless of the prepared doping levels. The results indicate that an unusual metal dispersal mechanism is taking place during the microemulsion synthesis, and they challenge a common assumption that doped silica nanoparticles have the same metal content as the average measured by bulk-sample methods.

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11

Tan, Changlong, Dianshuang Xu, Kun Zhang, Xiaohua Tian, and Wei Cai. "Electronic and Magnetic Properties of Rare-Earth Metals Doped ZnO Monolayer." Journal of Nanomaterials 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/329570.

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The structural, electronic, and magnetic properties of rare-earth metals doped ZnO monolayer have been investigated using the first-principles calculations. The induced spin polarization is confirmed for Ce, Eu, Gd, and Dy dopings while the induced spin polarization is negligible for Y doping. The localizedfstates of rare-earth atoms respond to the introduction of a magnetic moment. ZnO monolayer undergoes transition from semiconductor to metal in the presence of Y, Ce, Gd, and Dy doping. More interestingly, Eu doped ZnO monolayer exhibits half-metallic behavior. Our result demonstrates that the RE-doping is an efficient route to modify the magnetic and electronic properties in ZnO monolayer.

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12

Michalsky, Ronald, Peter H. Pfromm, and Aldo Steinfeld. "Rational design of metal nitride redox materials for solar-driven ammonia synthesis." Interface Focus 5, no. 3 (June 6, 2015): 20140084. http://dx.doi.org/10.1098/rsfs.2014.0084.

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Fixed nitrogen is an essential chemical building block for plant and animal protein, which makes ammonia (NH 3 ) a central component of synthetic fertilizer for the global production of food and biofuels. A global project on artificial photosynthesis may foster the development of production technologies for renewable NH 3 fertilizer, hydrogen carrier and combustion fuel. This article presents an alternative path for the production of NH 3 from nitrogen, water and solar energy. The process is based on a thermochemical redox cycle driven by concentrated solar process heat at 700–1200°C that yields NH 3 via the oxidation of a metal nitride with water. The metal nitride is recycled via solar-driven reduction of the oxidized redox material with nitrogen at atmospheric pressure. We employ electronic structure theory for the rational high-throughput design of novel metal nitride redox materials and to show how transition-metal doping controls the formation and consumption of nitrogen vacancies in metal nitrides. We confirm experimentally that iron doping of manganese nitride increases the concentration of nitrogen vacancies compared with no doping. The experiments are rationalized through the average energy of the dopant d-states, a descriptor for the theory-based design of advanced metal nitride redox materials to produce sustainable solar thermochemical ammonia.

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13

Continenza, Alessandra, Gianni Profeta, and Silvia Picozzi. "Transition metal doping in Ge." Journal of Magnetism and Magnetic Materials 310, no. 2 (March 2007): 2147–49. http://dx.doi.org/10.1016/j.jmmm.2006.10.940.

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14

Lanzani, G., T. Kangas, and K. Laasonen. "Copper passivation by metal doping." Journal of Alloys and Compounds 482, no. 1-2 (August 2009): 33–42. http://dx.doi.org/10.1016/j.jallcom.2009.03.180.

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15

Girlani, S. A., B. Yan, and P. C. Taylor. "Doping in metal chalcogenide glasses." Semiconductors 32, no. 8 (August 1998): 879–83. http://dx.doi.org/10.1134/1.1187476.

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16

Zhang, Pei Lin, Shu Yin, and Tsugio Sato. "Co-Doping Effect of Metal Ion on the Visible Light Responsive Photocatalytic Properties of Nitrogen Doped Titanium Dioxide." Advances in Science and Technology 63 (October 2010): 36–40. http://dx.doi.org/10.4028/www.scientific.net/ast.63.36.

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Different valences of metal ions such as Fe3+ and Nb5+ were co-doped with nitrogen ion into titanium dioxide by hydrothermal method using metal chlorides and hexamethylenetetramine as the sources of metal ions and nitrogen ion, respectively. The co-doping of low-content metal ion showed no noticeable influence on the crystalline phases and specific surface area (S.S.A.) of the samples. Doping with Fe ion could significantly enhance the absorption in visible light region, but doping with Nb ion showed almost no effect. The photocatalytic activities of the samples were determined for the oxidative destruction of NO gas under various wavelengths. Co-doping with Nb ion improved the deNOx ability, but co-doping with Fe ion depressed it, indicating that co-doping with higher valence metal ion was effective in reducing the vacancy in the lattice which acts as the recombination center of the photo-induced electrons and holes, and achieving higher photocatalytic activity.

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17

Tavkhelidze, Avtandil, Larissa Jangidze, Zaza Taliashvili, and Nima E. Gorji. "G-Doping-Based Metal-Semiconductor Junction." Coatings 11, no. 8 (August 7, 2021): 945. http://dx.doi.org/10.3390/coatings11080945.

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Geometry-induced doping (G-doping) has been realized in semiconductors nanograting layers. G-doping-based p-p(v) junction has been fabricated and demonstrated with extremely low forward voltage and reduced reverse current. The formation mechanism of p-p(v) junction has been proposed. To obtain G-doping, the surfaces of p-type and p+-type silicon substrates were patterned with nanograting indents of depth d = 30 nm. The Ti/Ag contacts were deposited on top of G-doped layers to form metal-semiconductor junctions. The two-probe method has been used to record the I–V characteristics and the four-probe method has been deployed to exclude the contribution of metal-semiconductor interface. The collected data show a considerably lower reverse current in p-type substrates with nanograting pattern. In the case of p+-type substrate, nanograting reduced the reverse current dramatically (by 1–2 orders of magnitude). However, the forward currents are not affected in both substrates. We explained these unusual I–V characteristics with G-doping theory and p-p(v) junction formation mechanism. The decrease of reverse current is explained by the drop of carrier generation rate which resulted from reduced density of quantum states within the G-doped region. Analysis of energy-band diagrams suggested that the magnitude of reverse current reduction depends on the relationship between G-doping depth and depletion width.

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Maswanganye, Mpho W., Guy L. Kabongo, and Mokhotjwa S. Dhlamini. "Modulating Charge Mobility in Microwave Synthesized Ti-doped ZnS Nanoparticles for Potential Photoanode Applications." Nanomaterials 13, no. 1 (December 23, 2022): 77. http://dx.doi.org/10.3390/nano13010077.

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Doping ZnS nanoparticles with different metal and/or non-metal ions is one of the ways to improve their properties. That is because dopants introduce strain into the lattice of the ZnS nanoparticles. The influence of Ti on the ZnS nanoparticles was investigated on the structural properties, optical properties, and also electrical impedance spectroscopy (EIS). The presence of Ti in the crystal lattice of the ZnS introduced strain into the crystal structure, hence causing a lattice expansion and reducing the crystallite sizes of the ZnS nanoparticles. Ti doping was observed to increase the energy band gap of ZnS nanoparticles and also reduce the charge carrier recombination. Doping Ti into ZnS was observed to decrease the charge transfer resistance of ZnS nanoparticles with an increase in dopant concentration indicating an improved charge transfer mobility owing to the presence of strain in the crystal lattice.

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Zhang, Xiayan, Xiaoyan Li, Yanli Zeng, Shijun Zheng, and Lingpeng Meng. "Enhancing σ/π-type copper(i)⋯thiophene interactions by metal doping (metal = Li, Na, K, Ca, Sc)." Dalton Transactions 44, no. 3 (2015): 1283–91. http://dx.doi.org/10.1039/c4dt02286f.

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Metal atom doping on thiophene can enhance the Cu⋯thiophene interactions. Enhancement factors are determined by electrostatic potentials of the molecular surface and the electronic configuration of the doping metal.

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20

Tammarugwattana, Narin, Kitipong Mano, Chaloempol Saributr, Adirek Rangkasikorn, Navaphun Kayunkid, Pitiporn Thanomngam, and Jiti Nukeaw. "Growth and Characterizations of Tin-Doped on Nickel-Phthalocyanine as a Novel Nanomaterial." Advanced Materials Research 1131 (December 2015): 39–42. http://dx.doi.org/10.4028/www.scientific.net/amr.1131.39.

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Tin-doped nickel phthalocyanine thin films (Sn-doped NiPc) were deposited by thermal co-evaporation method. Doping concentration of tin in NiPc was controlled via different deposition rates between metal dopent and host organic material. Properties of the thin films doped by tin in the range of 3 to 15% were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), UV-Visible spectroscopy and X-ray photoelectron spectroscopy (XPS). Furthermore, electrical properties of Al/Sn-doped-NiPc/ITO devices i.e. charge carrier concentration and carrier mobility were characterized by current-voltage and capacitance-voltage measurements. Microscopic results show clear evidence of the morphological transition from granular structure in undoped-film to rod-liked structure in the films doped more than 5%. Moreover, surface grain size exhibits the tendency to decrease with the increase of doping concentration. Optical properties reveal that the packing of NiPc molecules in all doping conditions is the combination of α-phase (majority) and β-phase (minority). However, evolution of β-phase NiPc is observed with the increase of doping concentration. Photoelectron analyses indicate shift of binding energy in both Ni2p and Sn3d levels corresponding to charge transfer between nickel-core and tin dopant. In addition, the electrical properties show the enhancement of the film’s conductivity due to the increase of charge carrier concentration with the higher Sn-doping level.

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CHEN, YU, CHUNWANG ZHAO, YUQIN GUAN, and ZHENDUO ZHANG. "CURIE TEMPERATURE OF 3d TRANSITION-METAL-DOPED GaAs." Modern Physics Letters B 26, no. 18 (June 17, 2012): 1250116. http://dx.doi.org/10.1142/s0217984912501163.

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The Zener model of ferromagnetism predicts that higher values of Curie temperature (CT) can be achieved by materials containing greater doping concentrations and hole concentrations. However, the prediction value is significantly higher than those from experiments with high doping concentrations. This discrepancy is resolved by an improved theoretical prediction for CT of 3d transition-metal-doped GaAs . Cr -doping results in higher CT than the Mn -doped GaAs. Maximum CT of Ga 1-x Mn x As is 215 K with 13.9% doping concentration. Room temperature CT can be achieved by 11.3% Cr -doped GaAs . Maximum CT of Ga 1-x Cr x As can reach 514.4 K with 31.7% doping concentration.

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Whang, Chin Myung, J. G. Kim, and Hae Jin Hwang. "Photocatalytic Properties of the Transition Metal Doped TiO₂ Powder Prepared by Sol-Gel Process." Key Engineering Materials 280-283 (February 2007): 647–50. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.647.

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Transition metal-doped TiO2 powders as a photocatalyst were prepared by sol-gel process and Sb, Bi and Nb were introduced into them as dopants. The photocatalytic behaviors of the doped TiO2 powder were studied as a function of dopant, doping concentration and preparation conditions. X-ray diffraction, FT-Raman, B.E.T. and scanning electron microscopy were applied for structural and microstructural studies. Optical properties of the doped TiO2 powders were studied by UV-Visible Spectrometer and photocatalytic activity of the doped TiO2 was characterized in terms of the degradation of 1,4-dichlorobenzene. X-ray difraction analysis showed that doping with a transition metal ion suppresses anatase-to-rutile phase transition compared with the pure TiO2. The Sb and Nb-doped TiO2 powders did not exhibit any other diffraction peaks except those belonging to TiO2. On the other hand, a diffraction peak of Bi4Ti3O12 appears for 5 at.% Bi-doped samples. All of the doped TiO2 powders had higher specific surface area than undoped TiO2. Surface area increased with increasing dopant concentration depending on the dopant, from 33.9 m2/g to 55.4m2/g. The UV-visible absorption spectra of doped samples were red-shifted by 20~50nm according to the doping level. Also transition metal doped TiO2 powders exhibited better photocatalytic activity than the undoped TiO2. The increase in photoactivity is probably due to the increase in the interfacial electron transfer, red shifts, and better crystallinity.

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Yu, Rundong. "The relationship between the fabrication and characteristics of nitrogen-doped graphene." Journal of Physics: Conference Series 2608, no. 1 (October 1, 2023): 012027. http://dx.doi.org/10.1088/1742-6596/2608/1/012027.

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Abstract Since the 21st century, with the popularization of computers and mobile phones to the upgrading of various kinds of electronic products, human needs are also changing, among which the flexible touch screen has received wide attention. To achieve a wide application of flexible touch screens, this paper needs to make more materials innovations, and graphene’s unique and excellent performance has attracted wide attention. Among them, the metal doping, non-metallic doping, metallic and non-metallic co-doping of graphite phase carbon nitride has broad development prospects, widely used, or may be widely used in the production and production of flexible touch screen. This paper briefly analyzes and compares three nitrogen-containing graphene materials’ properties and preparation methods (metal doping, non-metal doping, metal, and non-metal co-doping) in 2D nanomaterials, and discusses the possible applications in the field of flexible touch screens. Urea-reduced GO graphene, Fe-P co-doped graphite phase nitride carbon and potassium ion-doped graphite phase nitride carbon all have easy raw materials, simple production mode, electrical, and excellent optical properties; meanwhile, different doping methods and dosage change the performance of graphene in different directions. Therefore, nitrogen-containing graphene materials have a lot for development in the part of flexible touch screens.

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Dzujah, Diyan Unmu, Abdul-Muizz Pradipto, Rahmat Hidayat, and Kohji Nakamura. "Modification of plasmonic properties in several transition metal-doped graphene studied by the first principles method." RSC Advances 13, no. 2 (2023): 1446–54. http://dx.doi.org/10.1039/d2ra06446d.

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Doping graphene with a single transition metal atom results in bandgap opening and partial filling of the mid-gap states, leading to the possibility of plasmon excitation with plasmon frequency depending on the TM dopant.

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Jiang, Haiyan, Yang Li, Daohan Wang, Xiaodong Hong, and Bing Liang. "Recent Advances in Heteroatom Doped Graphitic Carbon Nitride (g-C3N4) and g-C3N4/Metal Oxide Composite Photocatalysts." Current Organic Chemistry 24, no. 6 (May 25, 2020): 673–93. http://dx.doi.org/10.2174/1385272824666200309151648.

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Industrial wastewater contains abundant organic dyes, antibiotics, pesticides, chemical fertilizers or heavy metal ions, which seriously deteriorate the ecological environment. Among the practical techniques for reducing water pollution, photocatalysis is a kind of sustainable solar energy conversion technique for removing organic contaminants. In this review, the advances in the preparation, modification, and doping of graphitic carbon nitride (g-C3N4), including non-metal doping, metal doping, dual- or tri-doping, are introduced firstly. Then, we systematically reviewed the recent progress of g-C3N4/metal oxide composite photocatalysts, including a g-C3N4/n-type metal oxide, such as TiO2, ZnO, SnO2, WO3, FexOy, CeO2, V2O5, MoO3, MnO2, Nb2O5, In2O3, and a g-C3N4/p-type metal oxide, such as Co3O4, Bi2O3, NiO and Cu2O. At last, we summarized the design principles for preparing heteroatom doped g-C3N4 and g-C3N4/metal oxide composites, and forecast the promising research directions. The main objective is to provide a guideline for designing highperformance heteroatom doped g-C3N4 and g-C3N4/metal oxide photocatalysts.

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Pelc, D., P. Popčević, M. Požek, M. Greven, and N. Barišić. "Unusual behavior of cuprates explained by heterogeneous charge localization." Science Advances 5, no. 1 (January 2019): eaau4538. http://dx.doi.org/10.1126/sciadv.aau4538.

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The discovery of high-temperature superconductivity in cuprates ranks among the major scientific milestones of the past half century, yet pivotal questions regarding the complex phase diagram of these materials remain unanswered. Generally thought of as doped charge-transfer insulators, these complex oxides exhibit pseudogap, strange-metal, superconducting, and Fermi liquid behavior with increasing hole-dopant concentration. Motivated by recent experimental observations, here we introduce a phenomenological model wherein exactly one hole per planar copper-oxygen unit is delocalized with increasing doping and temperature. The model is percolative in nature, with parameters that are highly consistent with experiments. It comprehensively captures key unconventional experimental results, including the temperature and the doping dependence of the pseudogap phenomenon, the strange-metal linear temperature dependence of the planar resistivity, and the doping dependence of the superfluid density. The success and simplicity of the model greatly demystify the cuprate phase diagram and point to a local superconducting pairing mechanism.

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Ye, Ming Quan, Ai Jun Han, Zhu Bo Liu, and Chen Wang. "Metal Ions Doped Complex Cobalt Blue Pigment Research." Advanced Materials Research 415-417 (December 2011): 194–99. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.194.

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Metal ions doped complex cobalt blue pigments are prepared by homogeneous precipitation, to investigate the effects of doping ions Zn2+，Mg2+，Ni2+and Y3+on some properties of the doped complex cobalt blue pigments, such as crystal structure, color, shading power and temperature resistance. Studies have shown that doping have little effect on the spinel crystal type and temperature resistance of the pigments ; ionic radius differences between doping ions and Co2 +cause lattice distortion and changes of lattice constant , thus affecting the ligand state spaces of Co2 +ion, color and shading power of complex cobalt blue pigment. The lattice constant of Zn2 +doped complex cobalt blue becomes larger with the increasing amount of Zn2 +; while doping Mg2 +and Ni2 +, the crystal lattice constants become smaller; when doping with Y3 +, Y3 +ions enter into CoAl2O4lattice, replacing some hexa-coordinate octahedral gap of Al3 +, ionic radius differences between Y3 +and Al3+cause lattice distortion, when doping amount of Y3 +increases to a certain extent, the phase in the form of Y2O3will be generated and it will maybe form a kind of CoYxAl2-xO4- Y2O3solid solution instead of the complete spinel structure.

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Burroughes, J. H., D. L. Rogers, G. Arjavalingam, G. D. Pettit, and M. S. Goorsky. "Doping-induced bandwidth enhancement in metal-semiconductor-metal photodetectors." IEEE Photonics Technology Letters 3, no. 7 (July 1991): 657–59. http://dx.doi.org/10.1109/68.87945.

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Li, Jie, Yuchen Zhou, Kun Liu, Yifan Wang, Hui Li, and Artem Okulov. "Tunable Electronic Transport of New-Type 2D Iodine Materials Affected by the Doping of Metal Elements." Molecules 28, no. 20 (October 19, 2023): 7159. http://dx.doi.org/10.3390/molecules28207159.

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2D iodine structures under high pressures are more attractive and valuable due to their special structures and excellent properties. Here, electronic transport properties of such 2D iodine structures are theoretically studied by considering the influence of the metal-element doping. In equilibrium, metal elements in Group 1 can enhance the conductance dramatically and show a better enhancement effect. Around the Fermi level, the transmission probability exceeds 1 and can be improved by the metal-element doping for all devices. In particular, the device density of states explains well the distinctions between transmission coefficients originating from different doping methods. Contrary to the “big” site doping, the “small” site doping changes transmission eigenstates greatly, with pronounced electronic states around doped atoms. In non-equilibrium, the conductance of all devices is almost weaker than the equilibrium conductance, decreasing at low voltages and fluctuating at high voltages with various amplitudes. Under biases, K-big doping shows the optimal enhancement effect, and Mg-small doping exhibits the most effective attenuation effect on conductance. Contrastingly, the currents of all devices increase with bias linearly. The metal-element doping can boost current at low biases and weaken current at high voltages. These findings contribute much to understanding the effects of defects on electronic properties and provide solid support for the application of new-type 2D iodine materials in controllable electronics and sensors.

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Mohamed Islam, Noor Zalikha, Hendrik Kosslick, Mat Tamizi Zainuddin, Zuhana Ahmad Zubir, Shamsul Azrolsani Abdul Aziz Nazri, Mohd Zahid Abdul Malek, Mohamed Izat Mohd Ezwan, Shahrul Nizam Md Salleh, and Mohd Syaifurizwan Abdul Aziz. "Effect of Single and Bimetallic Ni, V and Mn Transition Metal Ion Doping on the Properties of Anatase/Brookite TiO₂ Photocatalyst." Advanced Materials Research 1133 (January 2016): 527–31. http://dx.doi.org/10.4028/www.scientific.net/amr.1133.527.

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Titania with a mixture of anatase, rutile and brookite nanostructures have gained much attention lately due to their high photocatalytic activity. Pure titania (TiO2) with a mixture of anatase, rutile, brookite phase were synthesized by hydrothermal treatment using titanium isopropoxide (TTIP) and 1.0 M of urea. The titania were doped with 1wt% of single transition metal nickel (Ni), vanadium (V) and manganese (Mn) and 1 wt% bimetallic transition metal of Ni-V and Ni-Mn, respectively. Pure titania shows higher, 94 % degradation of ibuprofen (Ibp) as the presence of brookite phase in the structure. The band gap energy of titania was obtained using the Kubelka-Munk reflectance function decreased as doping a transition metallic dopant where the energy order are V<MN<Ni, respectively. Bimetallic dopant V and Mn contribute higher photocatalytic activities as decreasing band gap energy of Ni ion doping.

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Ghosh, Atanu, Omar F. Mohammed, and Osman M. Bakr. "Atomic-Level Doping of Metal Clusters." Accounts of Chemical Research 51, no. 12 (November 19, 2018): 3094–103. http://dx.doi.org/10.1021/acs.accounts.8b00412.

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Saucedo, E., L. Fornaro, N. V. Sochinskii, A. Cuna, V. Corregidor, D. Granados, and E. Dieguez. "Heavy metal doping of CdTe crystals." IEEE Transactions on Nuclear Science 51, no. 6 (December 2004): 3105–10. http://dx.doi.org/10.1109/tns.2004.839076.

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Cheng, Rong, Jincheng Xia, Junying Wen, Pingping Xu, and Xiang Zheng. "Nano Metal-Containing Photocatalysts for the Removal of Volatile Organic Compounds: Doping, Performance, and Mechanisms." Nanomaterials 12, no. 8 (April 13, 2022): 1335. http://dx.doi.org/10.3390/nano12081335.

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Volatile organic compounds (VOCs) in indoor air are considered a major threat to human health and environmental safety. The development of applicable technologies for the removal of VOCs is urgently needed. Nowadays, photocatalytic oxidation (PCO) based on metal-containing photocatalysts has been regarded as a promising method. However, unmodified photocatalysts are generally limited in applications because of the narrow light response range and high recombination rate of photo-generated carriers. As a result, nano metal-containing photocatalysts doped with elements or other materials have attracted much attention from researchers and has developed over the past few decades. In addition, different doping types cause different levels of catalyst performance, and the mechanism for performance improving is also different. However, there are few reviews focusing on this aspect, which is really important for catalyst design and application. This work aims to give a comprehensive overview of nano metal-containing photocatalysts with different doping types for the removal of VOCs in an indoor environment. First, the undoped photocatalysts and the basic mechanism of PCO is introduced. Then, the application of metal doping, non-metal doping, co-doping, and other material doping in synthetic metal-containing photocatalysts are discussed and compared, respectively, and the synthesis methods, removal efficiency, and mechanisms are further investigated. Finally, a development trend for using nano metal-containing photocatalysts for the removal of VOCs in the future is proposed. This work provides a meaningful reference for selecting effective strategies to develop novel photocatalysts for the removal of VOCs in the future.

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Turski, Henryk, Pawel Wolny, Mikolaj Chlipala, Marta Sawicka, Anna Reszka, Pawel Kempisty, Leszek Konczewicz, Grzegorz Muziol, Marcin Siekacz, and Czeslaw Skierbiszewski. "Role of Metallic Adlayer in Limiting Ge Incorporation into GaN." Materials 15, no. 17 (August 27, 2022): 5929. http://dx.doi.org/10.3390/ma15175929.

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Atomically thin metal adlayers are used as surfactants in semiconductor crystal growth. The role of the adlayer in the incorporation of dopants in GaN is completely unexplored, probably because n-type doping of GaN with Si is relatively straightforward and can be scaled up with available Si atomic flux in a wide range of dopant concentrations. However, a surprisingly different behavior of the Ge dopant is observed, and the presence of atomically thin gallium or an indium layer dramatically affects Ge incorporation, hindering the fabrication of GaN:Ge structures with abrupt doping profiles. Here, we show an experimental study presenting a striking improvement in sharpness of the Ge doping profile obtained for indium as compared to the gallium surfactant layer during GaN-plasma-assisted molecular beam epitaxy. We show that the atomically thin indium surfactant layer promotes the incorporation of Ge in contrast to the gallium surfactant layer, which promotes segregation of Ge to the surface and Ge crystallite formation. Understanding the role of the surfactant is essential to control GaN doping and to obtain extremely high n-type doped III-nitride layers using Ge, because doping levels >1020 cm−3 are not easily available with Si.

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Rohloff, Martin, Björn Anke, Dennis Wiedemann, Anna C. Ulpe, Olga Kasian, Siyuan Zhang, Christina Scheu, Thomas Bredow, Martin Lerch, and Anna Fischer. "Synthesis and Doping Strategies to Improve the Photoelectrochemical Water Oxidation Activity of BiVO4 Photoanodes." Zeitschrift für Physikalische Chemie 234, no. 4 (April 28, 2020): 655–82. http://dx.doi.org/10.1515/zpch-2019-1476.

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AbstractBiVO4 is one of the most investigated and most promising metal oxide based photoanode materials for photoelectrochemical (PEC) water oxidation. Although it has several advantages (suitable band gap around 2.4 eV, suitable valence-band position for water oxidation, low toxicity, high abundance), it suffers from slow charge-carrier transport properties, high surface recombination, and limited water-oxidation activity. In the present work, we review the synthesis and doping strategies that we developed in the last years to improve the PEC performance of BiVO4 photoanodes. Strategies ranging from single anion doping or cation doping to anion and cation co-doping will be presented for fluoride and molybdenum as anion and cation dopants, respectively. One major result is that co-doping allows combining the most important PEC specific benefits of each type of dopant, i.e. an increased charge-injection efficiency in case of fluoride as well as an increased charge-separation efficiency in case of molybdenum.

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Chen, Jiajia, Kai Wu, Huanhuan Ma, Wei Hu, and Jinlong Yang. "Tunable Rashba spin splitting in Janus transition-metal dichalcogenide monolayers via charge doping." RSC Advances 10, no. 11 (2020): 6388–94. http://dx.doi.org/10.1039/d0ra00674b.

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Two-dimensional Janus transition-metal dichalcogenides possess an intrinsic Rashba effect, which can be manipulated by charge doping. Electron doping can effectively strengthen the Rashba effect, while hole doping would weaken it.

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Zhang, Luying, Qingzhe Zhang, Peng Jiang, Ying Liu, Chen Zhao, and Yuhang Dong. "Effects of Alloying Element on Hydrogen Adsorption and Diffusion on α-Fe(110) Surfaces: First Principles Study." Metals 14, no. 5 (April 23, 2024): 487. http://dx.doi.org/10.3390/met14050487.

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Based on first principles density functional theory (DFT) methods, this study employed the Cambridge Serial Total Energy Package (CASTEP) module within Materials Studio (MS) software under the generalized gradient approximation to investigate the adsorption, diffusion behavior, and electronic properties of hydrogen atoms on α-Fe(110) and α-Fe(110)-Me (Mn, Cr, Ni, Mo) surfaces, including calculations of their adsorption energies and density of states (DOS). The results demonstrated that doping with alloy atoms Me increased the physical adsorption energy of H2 molecules on the surface. Specifically, Mo doping elevated the adsorption energy from −1.00825 eV to −0.70226 eV, with the largest relative change being 30.35%. After doping with Me, the chemical adsorption energy of two hydrogen atoms does not change significantly, among which doping with Cr results in a decrease in the chemical adsorption energy. Building on this, further analysis of the chemical adsorption of single atoms on the surface was conducted. By comparing the adsorption energy and the bond length between a hydrogen atom and iron/dopant metal atom, it was found that Mo doping has the greatest impact, increasing the bond length by 58.58%. Analysis of the DOS functions under different doping conditions validated the interaction between different alloy elements and H atoms. Simultaneously, simulations were carried out on the energy barrier crossed by H atoms diffusing into the metal interior. The results indicate that Ni doping facilitates the diffusion of H atoms, while Cr, Mn, and Mo hinder their diffusion, with Mo having the most significant effect, where its barrier is 21.88 times that of the undoped surface. This conclusion offers deep insights into the impact of different doping elements on hydrogen adsorption and diffusion, aiding in the design of materials resistant to hydrogen embrittlement.

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Kuznetsov, Vladimir G., Anton A. Gavrikov, Milos Krbal, Vladimir A. Trepakov, and Alexander V. Kolobov. "Amorphous As2S3 Doped with Transition Metals: An Ab Initio Study of Electronic Structure and Magnetic Properties." Nanomaterials 13, no. 5 (February 27, 2023): 896. http://dx.doi.org/10.3390/nano13050896.

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Crystalline transition-metal chalcogenides are the focus of solid state research. At the same time, very little is known about amorphous chalcogenides doped with transition metals. To close this gap, we have studied, using first principle simulations, the effect of doping the typical chalcogenide glass As2S3 with transition metals (Mo, W and V). While the undoped glass is a semiconductor with a density functional theory gap of about 1 eV, doping results in the formation of a finite density of states (semiconductor-to-metal transformation) at the Fermi level accompanied by an appearance of magnetic properties, the magnetic character depending on the nature of the dopant. Whilst the magnetic response is mainly associated with d-orbitals of the transition metal dopants, partial densities of spin-up and spin-down states associated with arsenic and sulphur also become slightly asymmetric. Our results demonstrate that chalcogenide glasses doped with transition metals may become a technologically important material.

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Kim, Suhwan, Minho Choi, and Jongsung Park. "Cerium-Doped Oxide-Based Materials for Energy and Environmental Applications." Crystals 13, no. 12 (November 24, 2023): 1631. http://dx.doi.org/10.3390/cryst13121631.

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Cerium is a rare-earth metal commonly used as a dopant in various metal oxides to enhance their performances or provide optoelectronic properties. Cerium oxide (ceria) is particularly valuable owing to its unique properties and applications in various fields, such as biomedical research, photovoltaics, and industrial catalytic processes. This review focuses on the use of cerium and ceria doping in the synthesis of SiO2 and ZnO. Studies have shown that Ce-doped SiO2 thin films exhibit luminescence properties and proton shielding capabilities, and that Ce-doped ZnO has potential applications in gas sensors. In this review, we highlight the potential for controlling the luminescence and optical characteristics of these materials via cerium doping, opening up possibilities for various technological advancements and potential applications of cosmic ray shielding in space photovoltaics.

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Gao, Xiao Rui, Kang Le Jiang, Yu Qiao Wang, and Yong Jing Hao. "Effect of Doped Metal Ions on the Electrochemical Performance of Nickel Hydroxide Electrode for Nickel/Metal Hydride Battery." Applied Mechanics and Materials 448-453 (October 2013): 2942–45. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.2942.

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Positive materials for nickel/metal hydride battery, nickel hydroxide doped by different metal ions were synthesized by coprecipitation, and subsequent hydrothermal treatment and anion exchange method. The structure of the samples was analyzed by XRD test, and the electrochemical performances were studied by galvanostatic charge-discharge, cyclic voltammetry and impedance tests. The obtained electrode material shows mainly β-Ni (OH)2structure when only doping Zn2+, while α-Ni (OH)2structure was obtained by only doping Al3+or co-doping Al3+and Zn2+. Ni (OH)2co-doped Al3+and Zn2+had fine cyclic stability, high number of exchanged electrons per nickel atom (the maximum is 1.93), small charge-transfer and proton-diffusion resistances.

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Rodwihok, Chatchai, Duangmanee Wongratanaphisan, Tran Van Tam, Won Mook Choi, Seung Hyun Hur, and Jin Suk Chung. "Cerium-Oxide-Nanoparticle-Decorated Zinc Oxide with Enhanced Photocatalytic Degradation of Methyl Orange." Applied Sciences 10, no. 5 (March 2, 2020): 1697. http://dx.doi.org/10.3390/app10051697.

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Cerium-oxide-nanoparticle-decorated zinc oxide was successfully prepared using a simple one-pot hydrothermal technique with different weight% Ce doping. It was found that an increase in Ce doping has an effect on the optical energy band-gap tunability. Ce dopant provides electron trapping on Ce/ZnO nanocomposites and also acts as a surface defect generator during hydrothermal processing. Additionally, a bi-metal oxide heterojunction forms, which acts as a charge separator to obstruct charge recombination and to increase the photodegradation performance. It was found that the methyl orange (MO) degradation performance improved with an increase in Ce doping. The decomposition of MO went from 69.42% (pristine ZnO) to 94.06% (7% Ce/ZnO) after 60 min under fluorescent lamp illumination.

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Piątkowska, Aleksandra, Magdalena Janus, Kacper Szymański, and Sylwia Mozia. "C-,N- and S-Doped TiO2 Photocatalysts: A Review." Catalysts 11, no. 1 (January 19, 2021): 144. http://dx.doi.org/10.3390/catal11010144.

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This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.

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Mehtab, Amir, Jahangeer Ahmed, Saad M. Alshehri, Yuanbing Mao, and Tokeer Ahmad. "Rare earth doped metal oxide nanoparticles for photocatalysis: a perspective." Nanotechnology 33, no. 14 (January 12, 2022): 142001. http://dx.doi.org/10.1088/1361-6528/ac43e7.

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Abstract Metal oxides are well-known materials that have been considered as the prominent photocatalysts. Photocatalysis is a promising way to address the environmental issues which are caused by fossil fuel the combustion and industrial pollutants. Lot of efforts such as doping of metal oxides with metals, non-metals have been made to enhance their photocatalytic activity. More specifically, in this review we have discussed detailed synthesis procedures of rare earth doped metal oxides performed in the past decades. The advantage of doping metal oxides with rare earth metals is that they readily combine with functional groups due to the 4f vacant orbitals. Moreover, doping rare earth metals causes absorbance shift to the visible region of the electromagnetic spectrum which results to show prominent photocatalysis in this region. The effect of rare earth doping on different parameters of metal oxides such as band gap and charge carrier recombination rate has been made in great details. In perspective section, we have given a brief description about how researchers can improve the photocatalytic efficiencies of different metal oxides in coming future. The strategies and outcomes outlined in this review are expected to stimulate the search for a whole new set of rare earth doped metal oxides for efficient photocatalytic applications.

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Li, Yuexiang, Shaoqin Peng, Fengyi Jiang, Gongxuan Lu, and Shuben Li. "Effect of doping TiO2 with alkaline-earth metal ions on its photocatalytic activity." Journal of the Serbian Chemical Society 72, no. 4 (2007): 393–402. http://dx.doi.org/10.2298/jsc0704393l.

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TiO2 photocatalysts doped with alkaline-earth metal ions were prepared by the impregnation and coprecipitation methods. The sample were characterized by XRD, XPS and IR spectroscopy. Their activities were evaluated by the photocatalytic production of hydrogen. The activities of the doped photocatalysts dopended on the size of the dopant ions and the doping method. The optimum molar contents of dopant ions Be2+, Mg2+, Ca2+, Sr2+, Ba2+ were 1.25, 1.25, 2.25, 2.25 and 2.25 at. %, respectively. The optimum calcination temperature and time were 400?C and 1 h. .

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45

Paick, Jihun, Seunghee Hong, Jy-Young Jyoung, Eun-Sook Lee, and Doohwan Lee. "Comparative Studies on Effects of Metal Cation (La) and Non-Metal Anion (N) Doping on CeO2 Nanoparticles for Regenerative Scavenging of Reactive Oxygen Radicals." Catalysts 13, no. 3 (March 11, 2023): 572. http://dx.doi.org/10.3390/catal13030572.

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The intrinsic effects of metal cation (La) and non-metallic anion (N) doping of CeO2 nanoparticles (NPs) for regenerative scavenging of reactive oxygen radicals were studied. La-doped CeO2 NPs were prepared by the conventional impregnation method at various La doping levels. N-doped CeO2 NPs were prepared by urea thermolysis with two different methods: (i) direct thermolysis of urea after physical mixing with CeO2 NPs and (ii) wet impregnation of CeO2 NPs with urea followed by thermolysis under inert N2 atmosphere. Physicochemical properties of samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and N2 sorption measurement. Radical scavenging properties of the samples were characterized by applying Fenton’s reaction. Results indicated that atomic N doping on CeO2 NPs significantly enhanced radical scavenging properties of CeO2 NPs, resulting in an activity of N-doped CeO2 about 3.6 times greater than the pristine CeO2 NPs and 1.6 times higher than the La-doped CeO2 NPs. This result suggests that anionic N doping of CeO2 NPs is highly effective in enhancing radical scavenging properties of CeO2 NPs, whereas such modifications have been typically practiced by hetero-metal doping with rare earth metal elements. A collective structure–property correlation analysis suggested that enhancement of radical scavenging properties of heteroatom-doped CeO2 NPs was largely attributed to an increase in surface oxygen vacancies on CeO2 NPs due to heteroatom doping.

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Zhong, Xue Chun, Zhan Chang Pan, Zhi Gang Wei, Shu Guang Xie, Zhen Jun Cheng, and Chu Min Xiao. "Experimental and Theoretical Study on Transition Metal Ion Doped TiO₂." Advanced Materials Research 233-235 (May 2011): 2219–22. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.2219.

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In this paper, TiO2crystallines doped with transition metal ions have been prepared by sol-gel method. The UV-visible spectra indicated that the doping with transition metal ions (especially Cu2+, Mn2+and Cr3+ions) could effectively improve the absorption of TiO2crystals in the visible-light range. The XRD results showed that the doping does not affect the anatase phase of TiO2. The band structure and the UV-vis absorption spectrum of Mn2+ions doped-TiO2were also calculated by DFT (density function theory) method, which indicated that the doping with transition metal ion could make the band gap of TiO2smaller and a red shift in optical absorption.

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Khan, Maryam, Hafiz Mohammad Mutee Ur Rehman, Rida Tehreem, Muhammad Saqib, Muhammad Muqeet Rehman, and Woo-Young Kim. "All-Printed Flexible Memristor with Metal–Non-Metal-Doped TiO2 Nanoparticle Thin Films." Nanomaterials 12, no. 13 (July 3, 2022): 2289. http://dx.doi.org/10.3390/nano12132289.

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A memristor is a fundamental electronic device that operates like a biological synapse and is considered as the solution of classical von Neumann computers. Here, a fully printed and flexible memristor is fabricated by depositing a thin film of metal–non-metal (chromium-nitrogen)-doped titanium dioxide (TiO2). The resulting device exhibited enhanced performance with self-rectifying and forming free bipolar switching behavior. Doping was performed to bring stability in the performance of the memristor by controlling the defects and impurity levels. The forming free memristor exhibited characteristic behavior of bipolar resistive switching with a high on/off ratio (2.5 × 103), high endurance (500 cycles), long retention time (5 × 103 s) and low operating voltage (±1 V). Doping the thin film of TiO2 with metal–non-metal had a significant effect on the switching properties and conduction mechanism as it directly affected the energy bandgap by lowering it from 3.2 eV to 2.76 eV. Doping enhanced the mobility of charge carriers and eased the process of filament formation by suppressing its randomness between electrodes under the applied electric field. Furthermore, metal–non-metal-doped TiO2 thin film exhibited less switching current and improved non-linearity by controlling the surface defects.

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Ahmed, Sabah M. "Characterization of Al-doped ZnO nanorods grown by chemical bath deposition method." Innovaciencia Facultad de Ciencias Exactas, Físicas y Naturales 6, no. 1 (December 28, 2018): 1–9. http://dx.doi.org/10.15649/2346075x.463.

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Introduction: In recent years a metal oxide semiconductors have been paid attention due to their excellent chemical and physical properties. ZnO (Zinc oxide) is considered as one of the most attractive semiconductor materials for implementation in photo-detectors, gas sensors, photonic crystals, light emitting diodes, photodiodes, and solar cells, due to its novel electrical and optoelectronic properties. There are different uses of metal oxide semiconductors such us, UV photodetectors which are useful in space research’s, missile warning systems, high ﬂame detectors, air quality spotting, gas sensors, and precisely calculated radiation for the treatment of UV-irradiated skin. ZnO is a metal oxide semiconductors and it is used as a transparent conducting oxide thin ﬁlm because it has the best higher thermal stability, best resistance against the damage of hydrogen plasma processing and relatively cheaper if one compares it with ITO. Materials and Methods: On glass substrates, Al-doped ZnO (AZO) nanorods have been grown by a low -cost chemical bath deposition (CBD) method at low temperature. The seed layer of ZnO was coated on glass substrates. The effect of the Al-doping on the aligned, surface morphology, density, distribution, orientation and structure of ZnO nanorods are investigated. The Al-doping ratios are 0%, 0.2%, 0.8% and 2%. The Aluminum Nitrate Nonahydrate (Al (NO3)3.9H2O) was added to the growth solution, which is used as a source of the aluminum dopant element. The morphology and structure of the Al-doped ZnO nanorods are characterized by field emission scanning electron microscopy (FESEM) and high-resolution X-ray diffractometer (XRD). using the radio RF (Radio frequency) magnetron technique. Results and Discussion: The results show that the Al-doping have remarkable effects on the topography parameters such as diameter, distribution, alignment, density and nanostructure shape of the ZnO nanorods. These topography parameters have proportionally effective with increases of the Al-doping ratio. Also, X-ray diffraction results show that the Al-doping ratio has a good playing role on the nanostructure orientation of the ZnO nanorods. Conclusions: The Aluminum Nitride Nanohydrate considered as a good Aluminum source for doping ZnONR. It is clear from FESEM results that the Al-doping of ZnONR has a remarkable effect on the surface topography of nanorods for all aluminum doping ratios. From XRD patterns, it concludes that as the Al-doping ratio increases, the reorientation of the nanostructure of ZnO increases towards [100] direction. The results obtained also have shown that the average diameter of a nanorod is increased with increasing the ratio of Al-doping.

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Natarajan, Thillai Sivakumar, Velusamy Mozhiarasi, and Rajesh J. Tayade. "Nitrogen Doped Titanium Dioxide (N-TiO2): Synopsis of Synthesis Methodologies, Doping Mechanisms, Property Evaluation and Visible Light Photocatalytic Applications." Photochem 1, no. 3 (October 18, 2021): 371–410. http://dx.doi.org/10.3390/photochem1030024.

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Titanium dioxide (TiO2) is one of the stable and potential metal oxide semiconductor nanomaterials with flexible properties which allows them to be used in a variety of applications (i.e., environmental remediation, energy storage and production, and also as a pigment in personal care products, etc.). However, its low surface area, poor adsorption capacity and high bandgap energy (~3.2 eV) prevents its full potency. Especially, TiO2 with high bandgap (~3.2 eV) reduces its visible light absorption capacity and catalytic efficiency. Various modification processes (i.e., metal and non-metal doping, composite materials (mixed metal oxide, high surface area adsorbents), and dye sensitization etc.) have been accomplished for stimulating the characteristics of TiO2 and the associated catalytic efficiency. Among the modifications, the non-metal doping process in TiO2, specifically nitrogen doping, is one of the efficient dopants for enhancing the photocatalytic efficiency of TiO2 in the presence of visible light irradiation. However, the morphology of TiO2, structural changes in TiO2 during N-doping, properties (e.g., morphology and electronic) of N-doped TiO2 and also reaction operational parameters (e.g., doping concentration) hold a greater impact for enhancing the photocatalytic properties of TiO2 either positively or negatively. Furthermore, the synthesis methodologies have a major influence on the synthesis of stable N-TiO2 with pronounced photocatalytic efficiencies. Nevertheless, the methodologies for highly stable N-TiO2 synthesis, properties evaluation and their correlation with photocatalytic efficiencies are still not appropriately stabilized to accomplish the commercial utilization of N-TiO2. Therefore, this review article focuses on the synopsis of various synthesis methodologies and either their efficiencies or inefficiencies, the mechanism involved in the doping processes, changes in the structural, electronic and morphological properties observed due to the N-doping along with the photocatalytic capacity. Furthermore, the opportunities, challenges and future requirements linked to the development of durable N-doped TiO2-based semiconductor nanomaterials for efficient catalytic performance is also represented.

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Tian, Shufang, and Qing Tang. "Activating transition metal dichalcogenide monolayers as efficient electrocatalysts for the oxygen reduction reaction via single atom doping." Journal of Materials Chemistry C 9, no. 18 (2021): 6040–50. http://dx.doi.org/10.1039/d1tc00668a.

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Journal articles on the topic 'Metal doping'

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