Auswahl der wissenschaftlichen Literatur zum Thema „Cu foam“

Closed-cell aluminum foam with different percentages of Cu was prepared by melt foaming method.The effect of Cu element on the quasi-static compressive properties of aluminum foam was investigated, both under as-cast and heat-treated conditions. The results showed that Cu element distributed in cell wall matrix mainly in the forms of Al-Cu solid solutions and AlCu3, Al6.1Cu1.2Ti2.7 intermetallics. Meanwhile, Cu-containing foams possessed much higher compressive strength than the commercially pure aluminum foams. Additionally, proper heat treatment could further improve the yield strength of Cu-containing foams and the effect of aging treatment was more obvious than the homogenizing heat treatment under the present conditions and the reasons were discussed.

In this mini-review we compare two prototypical metal foam electrocatalysts applied to the transformation of CO2 into value-added products (e.g. alcohols on Cu foams and formate on Bi foams). A substantial improvement in the catalyst performance is typically achieved through thermal annealing of the as-deposited foam materials, followed by the electro-reduction of the pre-formed oxidic precursors prior or during the actual CO2 electrolysis. Utilizing highly insightful and sensitive complementary operando analytical techniques (XAS, XRD, and Raman spectroscopy) we demonstrate that this catalyst pre-activation process is entirely accomplished in case of the oxidized Cu foams prior to the formation of hydrocarbons and alcohols from the CO2. The actually active catalyst is therefore the metallic Cu derived from the precursor by means of oxide electro-reduction. Conversely, in their oxidic form, the Cu-based foam catalysts are inactive towards the CO2 reduction reaction (denoted ec-CO2 RR). Oxidized Bi foams can be regarded as an excellent counter example to the above-mentioned Cu case as both metallic and the thermally derived oxidic Bi foams are highly active towards ec-CO2 RR (formate production). Indeed, operando Raman spectroscopy reveals that CO2 electrolysis occurs upon its embedment into the oxidic Bi2O3 foam precursor, which itself undergoes partial transformation into an active sub-carbonate phase. The potential-dependent transition of sub-carbonates/oxides into the corresponding metallic Bi foam dictates the characteristic changes of the ec-CO2 RR pathway. Identical location (IL) microscopic inspection of the catalyst materials, e.g. by means of scanning electron microscopy, demonstrates substantial morphological alterations on the nm length scale on the material surface as consequence of the sub-carbonate formation and the potential-driven oxide reduction into the metallic Bi foam. The foam morphology on a mesoscopic length scale (macroporosity) remains, by contrast, fully unaffected by these phase transitions.

Abstract Structured Pd/Al2O3 catalysts were fabricated by impregnating Pd onto Ni and Cu foams coated with Al2O3 layers. By testing the adhesion stability and catalytic activity in the combustion of methane, the superior performance of Ni-foam-supported Pd/Al2O3 catalyst was demonstrated, to its counterpart powder catalysts. The resultant structured catalysts enable the fabrication of lamellar microreactor systems. It is found that the metal foams influence the activity of catalyst layer, due to the diffusive penetration of metallic atoms into catalysts from metal foams. The Ni foam is beneficial for enhancing the activity of Pd/Al2O3 catalyst, while the Cu foam plays a negative role. The investigation to the model powder catalysts doped with Ni and Cu verified the modification of Ni and Cu to the physicochemical properties of Pd/Al2O3 catalyst, thereby the catalytic performances. Thus, it can be expected that the performance of structured catalysts may be improved by rationally designing and selecting proper supports.

AbstractA low-emission catalyst for the preparation of flexible polyurethane (FPUR) foams was developed. Copper-amine complex solutions in ethylene glycol (EG), namely, Cu(OAc)2(en)2-EG and Cu(OAc)2(trien)-EG (en, ethylenediamine; trien, triethylenetetramine), were synthesized and used as catalysts for the preparation of FPUR foams. The synthesis of Cu(OAc)2(en)2-EG and Cu(OAc)2(trien)-EG is convenient because the synthesis of copper-amine complexes can be done in situ using ethylene glycol as a solvent and no purification step is needed. It was found that Cu(OAc)2(en)2-EG was a suitable catalyst for FPUR foam preparation. In comparison to Dabco EG (or triethylenediamine), which is a commercial catalyst for FPUR foam preparation, Cu(OAc)2(en)2-EG had a comparable catalytic activity in gelling reaction and a higher catalytic activity in blowing reaction. The FPUR foam prepared from Cu(OAc)2(en)2-EG had a lower density than that prepared from Dabco EG.

The space holder method, a kind of powder metallurgy method which can avoid the process of melting metal to prepare metal foams, has particular significance in solving the difficulty of preparing metal foams with high melting points. In this paper, Na2S2O3·5H2O, a novel space holder, was used to prepare aluminium foam and copper foam, which were then used to test the heat dissipation performance of the metal foams. We first prepared two kinds of cell structures for (spherical cell and composite cells) aluminium and copper foam, then, we compared the performances of their heat dissipation, and it was found that both the spherical cell metal foam and composite cell metal foam promoted heat dissipation in the environment of natural convection, and the difference between them was not apparent. In the environment of forced convection, the composite porous metal showed a better heat dissipation performance.

<p>The applicability of nickel-copper metallic foams as a current collector was investigated for supercapacitor. A comprehensive characterization of Ni-Cu based foam was studied and the analysis of their structural, chemical, and electrochemical properties was evaluated. Structural characteristics and electrochemical methods were used to examine the surface morphology, and surface-chemical composition of the materials. The foams deposited at the time deposition of 180s exhibited dual-porosities (macro and mesopores) with pores ranging from13 to16 μm and the branch size ranged from 25 to 50 nm. Ni-Cu foam electrodes are employed as current collector for supercapacitor. Their usefulness as current collector was evaluated by well-defined experimental conditions using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge and discharge (GCD) techniques. The outcome of these experiments demonstrated that the Ni-Cu foams which was synthesized at the time deposition of 180s had pseudocapacitive behavior. The best value for specific capacitance which was calculated from GCD was (536 F/g at 1 mA/cm<sup>2</sup>) for the Ni-Cu foams deposited at 2 A/cm<sup>2</sup> for 180 s. The Ni-Cu foam sustained a current density of 15 mA/cm<sup>2</sup> after 2000 cycles without significant loss of supercapacitor activity.</p>

AbstractTwo metal acetate-ethanolamine complexes, namely Cu(OAc)2(EA) and Zn(OAc)2(EA), were synthesized from metal acetates [M(OAc)2, where M=Cu and Zn] and ethanolamine (EA). These metal acetate-ethanolamine complexes can be used as catalysts in the preparation of rigid polyurethane (RPUR) foams. Both Cu(OAc)2(EA) and Zn(OAc)2(EA) were obtained as viscous liquids, which have very weak odor and could be easily dissolved in the starting materials of RPUR foam formulation. The results were compared with RPUR foam prepared from dimethylcyclohexylamine (DMCHA), which is a commercial catalyst with very strong amine odor. Considering the gel time and rise time, Cu(OAc)2(EA) had higher catalytic activity than Zn(OAc)2(EA) and both metal acetate-ethanolamine complexes had lower catalytic activity than DMCHA. Density and compressive strength of RPUR foam catalyzed by Cu(OAc)2(EA) were comparable to that prepared from DMCHA.

Currently, one of the renewable energy sources is fuel cells, namely chemical energy is directly converted into electricity. Designing new or enhancing the existing fuel cells, much attention is devoted to the search of new effective catalysts, which would allow increasing the effectiveness of fuel cells and creating the background for designing new technologies for catalysts formation. The aim of the work is to form efficient and inexpensive nanostructured catalysts by electroplating 3D structure metal copper-nickel (Cu-Ni) foams on titanium (Ti) surface and decorating them with low amounts of platinum nanoparticles (PtNP) for the electrooxidation of sodium borohydride (NaBH4). The Cu-Ni foam was prepared by electrochemical deposition (I deposition=1.5 Acm-2, t deposition= 3,6 and 9 min) on Ti surface. The electrolyte contained 0.5 M Ni2+ ions, and the concentrations of Cu2+ ions ranged from 0.01 to 0.02 M. PtNP particles were deposited on Cu-Ni foam (noted (Pt(Cu-Ni)/Ti)) by immersion of Cu-Ni foam into 1 mM H2PtCl6 solution at 25 °C for 1 minute. The morphology and composition of the prepared catalysts were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The electrocatalytic activity of the 3D catalysts was evaluated towards the oxidation of borohydride by cyclic voltammetry method in 0.05 M NaBH4 solution in an alkaline media in the potential range from -1.2 to 0.6 V (vs. Ag/AgCl) and with an electrode potential scan rate of 10 mVs-1. The study showed that the prepared 3D Cu-Ni foam and Pt(Cu-Ni)/Ti have good electrochemical stability in alkaline NaBH4 solution. It was also observed that immersion of Cu-Ni foam in a platinum-containing solution for 1 min increased the electrocatalytic activity of the prepared Pt(Cu-Ni)/Ti catalysts for NaBH4 oxidation compared to Cu-Ni foam. Acknowledgment This project has received funding from European Social Fund (project No 09.3.3-LMT-K-712-19-0138) under a grant agreement with the Research Council of Lithuania (LMTLT).

Cu–Sn alloy foam is a promising electrode material for Li-ion batteries. In this study, Cu–Sn alloy foam was produced by diffusion-limited electrodeposition in alkaline electrolyte using polyurethane (PU) foam template. Our major concern is to form Cu–Sn alloy foam with nanocrystalline surface morphology by adjusting electrodeposition conditions such as deposition potential and metal ion concentration. Cu–Sn alloy layers comprising of nanoclusters such as nanospheres, nanoellipsoids, and nanoflakes were created depending on electrodeposition conditions. Larger surface area of nanocluster-interconnected Cu–Sn alloy layer was created when both Sn concentration and negative deposition potential were higher. After decomposing PU template thermally, Cu–Sn alloy foam of Cu, Cu6Sn5, and Cu3Sn phases was finally produced.

Ni foam with 3D porous structure has attracted attention in the field of catalysis. Expanding the specific surface area of Ni foam is an important method to enhance its chemical properties. In this study, the Cu-Ni/Ni foam were obtained by electroless plating copper on Ni foam and then heat treatment for homogenizing at 750°C. The dealloying of the Cu-Ni/Ni foam was carried out by electrochemical etching for obtaining the Ni foam with hierarchical pore structure. The microstructure, phase and electrochemical performance were characterized by SEM, XRD and electrochemical testing. The results showed that the optimized temperature of electroless plating Cu on Ni foam is 60oC. Ni-Cu alloy can be obtained by counter diffusion above 750°C. With prolonging time of etching, the content of Cu component decreased and the size of pores on the sturts of the Cu-Ni/Ni foam changed from nano to micro scale. The electrochemical properties of the alloywere significantly higher than that of the pure nickel foam.

Les sollicitations thermiques élevées et répétées subies lors des freinages des trains à grande vitesse provoquent des fissures de fatigue thermique, entraînant une défaillance des matériaux de frein. Les patins de frein composites à base de cuivre (Cu) utilisés sous forme de poudres sont choisis pour améliorer la dissipation thermique des systèmes de freinage. Cependant, les nouvelles normes environnementales internationales exigent une réduction de la teneur en Cu, entrant en conflit avec le bon maintien des propriétés thermiques. Il est proposé dans ce travail d'utiliser des mousses de Cu architecturées avec un réseau continu sous la forme d'un volume élémentaire représentatif (VER) permettant un meilleur contrôle du flux thermique. Des simulations numériques FEM sont d'abord réalisées pour étudier la faisabilité de l'optimisation de la capacité de transfert de chaleur en passant par des mousses de Cu. Les résultats de la simulation montrent que la diffusivité thermique considérant les VERs peut être considérablement améliorées. En particulier localement, lorsque la taille du VER est réduite. Ainsi, le travail suivant se concentre sur la réduction de la taille du VER des mousses de Cu produites par la méthode de fabrication additive (FA) assistée par la fonderie à la cire perdue. Des patins bimétalliques basés sur des mousses de Cu sont ensuite produits par une technologie de pressage à chaud. Leur comportement thermique est étudié. Expérimentalement, les résultats montrent d'une part que les mousses de Cu avec une taille de VER jusqu'à 2 mm sont techniquement fabricables. D'autre part, un essai tribologique est effectué. Les mousses de Cu avec une taille réduite de VER peuvent optimiser la capacité de transfert de chaleur des patins de frein de manière significative en accord avec les résultats numériques. Enfin, cette nouvelle configuration montre la stabilité du freinage en favorisant la formation d'un troisième corps<br>The high and repeated thermal stresses during the braking of high-speed trains result in thermal fatigue cracks, leading to braking material failures. Composite braking pads based on copper (Cu) matrix in powder form are chosen to improve thermal dissipation of braking system. However, new international environmental standards require a reduction in Cu content, conflicting with maintaining the proper thermal properties. It is proposed in this work to utilize Cu foams architected with a continuous network in the form of a representative elementary volume (REV) enabling better control of heat flow. FEM numerical simulations are first carried out to investigate the feasibility of optimizing heat transfer ability by using Cu foams. Simulation results show that the thermal diffusivity considering REVs can be significantly improved. Especially locally, when the REV size is reduced. Thus, the following work focuses on reducing REV size of Cu foams produced by additive manufacturing (AM) assisted investment casting. Bimetallic pads based on Cu foams are then produced by a hot-pressing technology. Their thermal behavior of the produced pads is studied. Experimental results show that Cu foams with a REV size of up to 2 mm can be technically fabricated. In addition, a tribological test is also carried out. Cu foams with a reduced REV size can significantly optimize the heat transfer capacity of braking pads, in line with the numerical results. Finally, this new configuration demonstrates braking stability by promoting the formation of a third body

Lignin is a natural by-product coming from lignocellulosic biomass. Due to its polymeric aromatic structure, it is becoming an attractive source of aromatic building blocks, but the complexity and the heterogeneity of this material makes its depolymerization challenging. Among the possible depolymerization treatments, electrocatalysis has been adopted in this work to depolymerize lignin in mild conditions, applying renewable electricity, by means of a metal electrocatalyst. The electrocatalytic reaction has been conducted into a three-electrode cell, connected to a potentiostat, and registered by chronoamperometry experiment. Four types of catalysts have been tested: Ni bare, Cu bare, calcined Ni and calcined Cu. All of them have been characterized chemical-physically by SEM, XRD and Raman and electrochemically by cyclic voltammetry. Their activities have been evaluated by comparing obtained yield of vanillin, acetovanillone and guaiacol, the most recurrent products. Ni bare displayed the highest total yield. The effects of applied potential and reaction time on total products yields were evaluated. The best operating conditions were found to be 0.7 V applied potential and 10 minutes reaction time. 0.5 w/w% of vanillin yield was reached by applying 0.8 V.

碩士<br>國立中興大學<br>化學系所<br>103<br>A Cu+ ion-mediating Pt reduction used to prepare nanoparticle Pt-embedded Nafion (NF(Ptnano)) composites with well-dispersed and protective agent-free Pt nanocrystals with narrow particle size(~2.1 nm) distribution is described. Cu+ accumulated in Nafion via the electrochemical reduction of Cu2+ serves as a movable mediator to reduce PtCl42- to Pt. The NF(Ptnano) composites were probed as a function of composition and particle size distribution using powder X-ray diffraction (XRD),transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical characterization. The Pt nanoparticles distributed in the Nafion film electrically communicate with the electrode without any mediators or carbon support. The highly catalytic performance of the NF(Ptnano) composite as a potential electrocatalytic material for facilitation of the oxygen reduction reaction (ORR) was demonstrated. The electrocatalytic activity of Pt-embedded Nafion catalysts for ORR was investigated with cyclic voltammetry and rotating disc electrode (RDE) voltammetry experiments.

碩士<br>國立中興大學<br>化學系所<br>104<br>A Cu(I)-ion-mediating Au reduction is proposed for preparing an Au-nanoparticle-embedded nafion (NF(Aunano)) composite. The NF(Aunano) composite consisted of highly dense, well-dispersed, and protecting-agent-free Au nanocrystals with a narrow particle size (4.8±0.1 nm) distribution. The NF(Aunano) composite was characterized as a function of composition and particle size distribution using powder X-ray diffraction, transmission electron microscopy, and electrochemical measurements. It was demonstrated that the NF(Aunano) composite provided high activity in the redox behavior of As(III), and was used as a potential sensing material with low Au loading for As(III) detection. An NF(Aunano)-composite-modified electrode is easy to prepare and regenerate. The dynamic range of a calibration curve from 0.1 to 12.0 μg/L (from 1.3 to 160 nM), y=23.98x (in μA/μM)+0.42 (R2=0.999), showed linear behavior with a slope of 23.98 μA/μM. The detection limit is as low as 0.047 μg/L (0.63 nM). The chelating agent ethylenediaminetetraacetate (EDTA) can selectively chelate with interfering metal ions, forming bulky complexes or bulky anions that are excluded from the NF film. The presence of EDTA effectively eliminated interference from several metal ions, particularly Cu(II) and Hg(II), which are generally considered to be major interferents in the electroanalysis of As(III). This method was applicable to As(III) analysis in three real water samples, namely groundwater, lake, and drinking waters.

Alla luce del recente allarmante tasso di esaurimento delle riserve di combustibili fossili e al contemporaneo drastico aumento dei livelli di CO2 nell'atmosfera, principale gas serra responsabile del riscaldamento globale e di cambiamenti climatici molto gravi, una delle priorità assolute nella ricerca a livello mondiale è quella di sfruttare il più possibile le fonti di energia rinnovabile. Una possibilità molto interessante è quella di realizzare un processo di riduzione della CO2 a combustibili liquidi che sfrutti energie rinnovabili, quale quella solare, mediante dispositivi più comunemente noti come celle fotosintetiche artificiali o foglie artificiali o celle foto-elettro-catalitiche (PEC). L'obiettivo principale di questo lavoro, è stato pertanto quello di condurre uno studio approfondito su due diversi sistemi elettrocatalitici di riduzione della CO2 a prodotti liquidi con un più alto valore aggiunto, uno operante in fase gassosa (cioè in assenza di elettrolita al catodo) e uno operante in fase liquida. In particolare, è stata progettata e utilizzata nel processo di conversione della CO2, un’innovativa cella in fase liquida operante su scala di laboratorio, sulla falsariga della cella in fase gas precedentemente sviluppata all’Università di Messina. Il lavoro è stato svolto principalmente presso il laboratorio CASPE/INSTM dell’Università degli Studi di Messina (Dipartimento di Ingegneria Elettronica, Chimica e Ingegneria Industriale). Un periodo di sei mesi è stato svolto invece, nel corso del secondo anno di dottorato, presso l’École supérieure de chimie, physique, électronique de Lyon (CPE Lyon). In tale periodo sono stati sintetizzati, mediante innovative tecniche di sintesi organometallica, materiali compositi da utilizzare come elettrocatalizzatori nel processo di riduzione della CO2. Sono state effettuate molteplici prove sperimentali utilizzando svariate tipologie di catalizzatori, sia in fase gas che in fase liquida, al fine di indagare la differente selettività, produttività e varietà di prodotti ottenuti. Il processo in fase liquida è infatti quello maggiormente studiato in letteratura, ma esistono alcune problematiche che devono essere superate per consentire un successivo semplice scale up. quali ad esempio, la scarsa solubilità della CO2 e la tipologia di prodotti ottenuti (principalmente acido formico). Lo scopo principale di questo lavoro è stato quello di preparare nuovi materiali a base di carboni dopati con metalli, catalizzatori questi molto diversi da quelli comunemente utilizzati nel processo di riduzione della CO2 (generalmente metalli in bulk), e di testarli sia in fase gas (per sfruttare i vantaggi di questa condizione, quali ad esempio facile recupero dei prodotti e alta qualità dei prodotti stessi) sia in fase liquida (per avere un miglior confronto con i dati ampiamente presenti in letteratura). Per gli studi sulla riduzione elettrocatalitica della CO2 nella cella operante in fase gassosa, sono stati preparati una serie di elettrodi (basati su nano particelle –NP- di Cu, Fe, Pt e Cu/Fe depositate su nanotubi di carbonio o carbon black e successivamente poste all'interfaccia tra una membrana di Nafion e uno strato a diffusione di gas –GDL-). I risultati ottenuti sono stati molto promettenti, sia in termini di tipologia di prodotti formati che di produttività. In fase gas (senza elettrolita) è stata osservata la formazione di prodotti ≥C1 quali etanolo, acetone e isopropanolo, in particolare utilizzando il Fe (seguito dal Pt), evidenziando che anche metalli non nobili possono essere usati in maniera efficiente in questo processo. Per migliorare la produttività nella reazione di riduzione della CO2, sono stati preparati elettrodi differenti, basati su coating con sostituti zeolitici imidazolici (SIM-1) tipo MOF. In particolare, i catalizzatori testati sono stati MOF modificati con Fe-CNT, Pt-CNT, e CuFe-CNT. E’ stato osservato un cambiamento significativo in termini di produttività e anche di selettività verso i prodotti finali. Nel dettaglio, in particolare per il catalizzatore a base di MOF modificato con Pt, è stato osservato un aumento nei prodotti carboniosi e anche una selettività più alta verso prodotti con un più elevato numero di atomi di C. Per quanto riguarda lo studio del processo di riduzione elettrocatalitica della CO2 utilizzando la cella operante in fase liquida, sono state preparate tipologie di elettrodi simili ai precedenti. Inizialmente infatti, sono stati studiati elettrodi a base di nanoparticelle metalliche (Cu, Fe, Pt, Ru, Co) depositate su nanotubi di carbonio o carbon black. L'ordine relativo della produttività nella riduzione elettrocatalitica della CO2 in questa serie di elettrodi, è però risultato essere diverso rispetto alla fase gassosa, indicando quindi un differente percorso di reazione. In termini di produttività totale, gli elettrodi a base di Pt hanno consentito di ottenere le migliori performance, seguiti da Ru e Cu, mentre il Fe ha dato risultati peggiori. Sulla base dei risultati sperimentali ottenuti, è stato inoltre ipotizzato un possibile meccanismo di reazione. Successivamente, per cercare di migliorare ulteriormente le prestazioni nel processo di riduzione della CO2 in fase liquida, è stato effettuato uno studio approfondito, volto ad indagare la dipendenza di tale processo dalle dimensioni delle nanoparticelle metalliche. A tale scopo sono stati utilizzati elettrodi a base di nanoparticelle metalliche (Ru, Fe, Pt e Cu) su nanotubi di carbonio (CNT) depositati su GDL. Sono state sintetizzate nanoparticelle metalliche di diverse dimensioni utilizzando molteplici tecniche di sintesi: (i) impregnazione che ha consentito di ottenere NP di dimensioni comprese tra 10-50 nm; (ii) sintesi organometallica che ha consentito di ottenere NP uniformi e ultrafine con dimensioni comprese tra 1-5 nm. (ad esempio sono state sintetizzate NP di Fe di 1-3 P nm) (iii) sintesi mediante nanowires che ha consentito di ottenere NP di rame ultrafine con dimensioni comprese tra 2-3,8 nm. In particolare, la novità dell’approccio mediante nanowires sta nella possibilità di ottenere particelle di dimensioni molto piccole sintetizzando inizialmente i Cu NWs, mettendoli poi a contatto con il supporto carbonioso e facilitandone il suo trasferimento, ciò grazie alle forze intermolecolari di attrazione dei gruppi funzionali presenti sui CNT parzialmente ossidati. Inoltre, a differenza della sintesi organometallica, tale approccio permette di condurre le reazioni in aria e non in atmosfera inerte. I valori di produttività ottenuti sono stati 5-30 volte più alti utilizzando nanoparticelle metalliche più piccole (ottenute via nanowires o mediante sintesi organometallica) rispetto alle nanoparticelle metalliche più grandi (ottenute per impregnazione). I risultati sperimentali indicano pertanto che le NP di dimensioni più piccole hanno un ruolo fondamentale nelle performance catalitiche. Inoltre, il carico di NP metalliche è stato significativamente ridotto dal 10% al 1-2% in peso consentendo di ottenere, per le NP più piccole, una produttività equivalente o addirittura superiore rispetto alle nanoparticelle più grandi. In seguito, è stato effettuato anche uno studio sul possibile riutilizzo degli elettrodi di lavoro e sulla disattivazione per tempi di reazione più lunghi. E’ stata infine preparata una diversa tipologia di elettrodi a base di nano-foams su lastrine metalliche, al fine di ottenere un ulteriore miglioramento nel processo di riduzione elettrocatalitica della CO2. Le nano-foams o dendriti, sono state preparate mediante la tecnica di deposizione elettrochimica ed è stato effettuato uno studio preliminare di ottimizzazione, al fine di determinare le condizioni di sintesi più adatte. In aggiunta, è stato eseguito uno studio specifico per ottimizzare il valore di Voltaggio da utilizzare nelle prove catalitiche, mediante sia test di voltammetria ciclica che test completi di riduzione della CO2. Sono stati testati nano-foams a base di Cu e Fe depositati su fogli di Cu Fe, Al, di Inconel e su una griglia di Al. L’aumento nella produttività usando queste tipologie di elettrodi, è stata nell’ordine di 2-10 volte rispetto alla massima produttività ottenuta utilizzando NP metalliche su materiali carboniosi. Svariate tecniche analitiche sono state poi utilizzate per caratterizzare in modo approfondito i materiali preparati tra cui, microscopia elettronica a trasmissione (TEM), microscopia elettronica a scansione (SEM), spettroscopia ad assorbimento atomico (AAS), diffrazione a raggi X (XRD), spettroscopia fotoelettronica a raggi X (XPS), determinazione dell’area superficiale mediante metodo Brunauer-Emmett-Teller (BET). La determinazione dei prodotti di reazione è stata effettuata invece mediante cromatografia ionica (IC), gas cromatografia con rivelatore a spettrometria di massa (GC-MS), gas cromatografia (GC) con rivelatore a termo conducibilità (TCD).<br>In view of the recent alarming rate of depletion of fossil fuel reserves and the drastic rise in the CO2 levels in the atmosphere leading to global warming and severe climate changes, tapping into all kinds of renewable energy sources has been among the top priorities in the research fields across the globe. One of the many such pathways is CO2 reduction to fuels using renewable energies, more commonly referred as artificial photosynthetic cells or artificial leaves or photo-electro-catalytic (PEC) cells. The key objective of the present PhD work was to conduct in-depth studies on two different electro-catalytic CO2 reduction systems: electrolyte-less cell (gas phase) and electrolytic cell (liquid phase). In particular, a novel lab scale liquid phase cell, on the similar lines of the previously realized gas phase cell at the University of Messina, was developed and used to convert electro-catalytically CO2 to more value-added products. The work was carried out at the Laboratory CASPE/INSTM of the University of Messina (Department of Electronic Engineering, Industrial Chemistry and Engineering). During the second year, a six-month period was spent at the École supérieure de chimie, physique, électronique de Lyon (CPE Lyon), where organometallic routes were explored for the synthesis of novel composite materials to be used as electrocatalysts in the CO2 reduction process. Experimental tests were carried out on various types of catalysts in both the gas and liquid phase cells to understand the different selectivity, productivity and the reaction products obtained. Liquid phase, in fact, has been the most studied process in literature, but some issues mainly related to CO2 solubility and types of products formed (i.e. mainly formic acid), have never be allowed to pass the lab scale stage. The general aim of this PhD was to prepare novel metal doped nanocarbon substrates, which are very different with respect to the conventional metal bulk layers used as electrocatalysts in CO2 reduction, and test them both in gas phase (to take advantage of these conditions, i.e easy recovery and improved quality of the products) and in liquid phase (to have a better comparison with conditions typically adopted in literature). For the studies on the electro-catalytic reduction of CO2 in gas phase cell, a series of electrodes (based on Cu, Fe, Pt and Cu/Fe metal nanoparticles – NPs - deposited on carbon nanotubes – CNTs - or carbon black and then placed at the interface between a Nafion membrane and a gas diffusion-layer) were prepared. The results, evidencing the various types of products formed and their different productivities, are very promising. Under electrolyte-less conditions, the formation of ≥C1 products (such as ethanol, acetone and isopropanol) were observed, the highest being for Fe and closely followed by Pt, evidencing that also non-noble metals can be used as efficient catalysts under these conditions. To enhance the productivities of the CO2 reduction, a different set of electrodes were also prepared based on substituted Zeolitic Imidazolate (SIM-1) type MOF coatings during a stay at CPE Lyon and Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON). Particularly, the catalysts tested were MOF-based Fe-CNTs, Pt-CNTs and Cu/Fe-CNTs. There was a significant change in the reaction products and in the selectivity towards the end-products. Particularly, especially for the MOF modified Pt based catalyst, there was an increase in the C-products and also a better selectivity towards higher C-products. Moving to the studies on the electro-catalytic reduction of CO2 in liquid phase cell, a similar set of electrodes were prepared. Initially, electrodes based on metal NPs of Cu, Fe, Pt, Ru and Co deposited on CNTs or carbon black were studied for their CO2 reduction capability. The relative order of productivity in CO2 electro-catalytic reduction in these series of electrodes was found to be different between the gas and liquid phase cells indicating the different reaction pathways. For liquid phase conditions, in terms of net C-products, catalytic electrodes based on Pt topped the class, closely followed by Ru and Cu, while Fe got the lowest position. The probable underlying reaction mechanism was also provided. In order to improve further the performances of the CO2 reduction in liquid phase conditions, a metal NPs size dependant study on the electro-catalytic reduction of CO2 to fuels was carried out. This study was performed using electrodes based on metal NPs of Ru, Fe, Pt and Cu loaded on CNTs and then transferred on a gas diffusion layers (GDL). Varied sized metal NPs have been synthesized using different techniques: (i) impregnation route to achieve NPs in the size range of 10-50 nm; (ii) organometallic approach to synthesize uniform and ultrafine NPs in the size range of 1-5 nm (i.e., Fe NPs were synthesized through a novel synthesis route to attain 13 nm NPs);(iii) Nanowire (NW) top-down approach to obtain ultrafine copper metal NPs in the size range of 2-3.8 nm. Particularly, the novelty of nanowire approach is the ability to obtain very small metal NPs starting from the synthesis of Cu NWs and then transferring the Cu onto the carbon surface, taking advantage of the different inter-forces of between Cu NWs and the functional groups present on the partially oxidized CNT surface. Furthermore, unlike the case of organo-metallic approach, this approach allows a preparation under air avoiding the use of potentially demanding inert atmospheric conditions. The enhancements in the fuel productivity were found to be 5-30 times higher for the smaller metal NPs obtained via organo-metallic route or nanowire route as compared to the larger metal NPs obtained via impregnation route. The results signify that the smaller sized metal NPs loading on the CNTs have a prevailing role in the catalytic performance and the selectivity towards different products. Moreover, the percentage of metal NPs loading was significantly reduced from 10 to 1-2 wt. % producing higher or equivalent fuels for small NPs as compared to the larger NPs. The reusability of the working electrodes and long reaction times (until 24 hours) were also probed. A different set of electrodes based on nano-foams on metal foils, were also investigated to achieve further improvements in the electro-reduction of CO2 to fuels. These nano-foams or dendrites were prepared by electrochemical deposition technique. Optimization studies on the deposition of these foams were performed initially to fix the set of preparation conditions. Moreover, voltage optimization study was performed using cyclic voltammetry and full CO2 reduction tests to find the optimum voltage for the process. The nano-foam electrodes tested include Cu and Fe foams on Cu foil, Fe foil, Al foil, Inconel foil and Al grid/mesh. The enhancements in the fuel productivity for various foams were in the range of 2-10 times greater as compared to the highest net fuel productivity achieved using metal NPs doped carbon catalytic electrodes, from all the previous studies. Various characterizations and analysis tools were used to analyse the catalysts qualitatively and quantitatively, which include Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Absorption Spectroscopy (AAS), X-ray diffraction (XRD), X-ray Photo-electron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). To determine the fuel productivities, Ion Chromatography (IC), Gas Chromatography-Mass Spectrometer (GC-MS), Gas Chromatography (GC) were used.<br>Compte tenu du récent taux alarmant d'épuisement des réserves de combustibles fossiles et de l'augmentation drastique des niveaux de CO2 dans l'atmosphère qui a conduit au réchauffement de la planète et à des changements climatiques sévères, l'exploitation de toutes sortes d'énergies renouvelables a été la Parmi les principales priorités de la recherche Champs à travers le monde. L'une des nombreuses voies de ce genre est la réduction du CO2 aux combustibles utilisant des énergies renouvelables, plus communément appelées cellules photosynthétiques artificielles ou feuilles artificielles ou cellules photoélectro-catalytiques (PEC). L'objectif principal de ce travail était de réaliser des études approfondies sur les différents systèmes de réduction électro-catalytique du CO2, à savoir les cellules sans électrolyte (phase gazeuse) et les cellules électrolytiques (phase liquide). Dans ce processus, nous avons conçu une nouvelle cellule en phase liquide à échelle de laboratoire sur les lignes similaires de la cellule de phase gazeuse de modèle précédemment modélisée. Des essais expérimentaux sur la réduction du CO2 ont été réalisés sur différents types de catalyseurs dans les deux cellules afin de comprendre la sélectivité, la productivité et les produits de réaction obtenus. L'obtention de résultats de test dans les deux cellules nous a permis d'effectuer une comparaison décente avec les résultats de réduction électro-catalytique de CO2 existants dans la littérature. Des essais expérimentaux ont été réalisés sur différents types de catalyseurs à la fois dans les cellules en phase gazeuse et en phase liquide pour comprendre la sélectivité, la productivité et les produits de réaction obtenus. La phase liquide, en fait, a été le processus le plus étudié dans la littérature, mais certaines questions liées principalement à la solubilité du CO2 et aux types de produits formés (c'est-à-dire principalement l'acide formique) n'ont jamais été autorisées à franchir le stade de l'échelle du laboratoire. L'objectif général de ce doctorat était de préparer de nouveaux substrats de nanocarbone dopés par des métaux, qui sont très différents par rapport aux couches en vrac métalliques conventionnelles utilisées comme électrocatalyseurs dans la réduction de CO2, et de les tester en phase gazeuse (pour profiter de ces conditions, Une récupération facile et une qualité améliorée des produits) et en phase liquide (pour une meilleure comparaison avec les conditions typiquement adoptées dans la littérature). Pour les études sur la réduction électro-catalytique du CO2 en phase gazeuse, une série d'électrodes (à base de nanoparticules de Cu, Fe, Pt et CuFe déposées sur des nanotubes de carbone ou de noir de carbone puis placées à l'interface entre une membrane Nafion et Une électrode à couche de diffusion de gaz). Les résultats démontrent le type divers de produits formés et leurs productivités. Dans des conditions sans électrolyte, la formation de produits ≥C1 tels que l'éthanol, l'acétone et l'isopropanol a été observée la plus élevée étant pour Fe et suivie de près par Pt. Pour améliorer les productivités de la réduction du CO2, un ensemble différent d'électrodes a été préparé sur la base de revêtements MOF de type imidazolate de type zéolitique substitué (SIM-1) lors d'un séjour au CPE Lyon et à l'Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON). Les catalyseurs testés étaient Fe-CNT, Pt-CNT et CuFe-CNT basés sur MOF. Il y a eu un changement significatif dans les produits de réaction et aussi, la sélectivité vis-à-vis des produits finaux. Pour le catalyseur à base de Pt modifié, MOF, il y avait une augmentation des produits C et également une sélectivité différente tandis que pour le catalyseur à base de Fe, il y avait une légère diminution des produits C. En se reportant aux études sur la réduction électro-catalytique du CO2 dans une cellule en phase liquide, un ensemble similaire d'électrodes a été préparé afin d'obtenir une bonne comparaison des résultats dans les expériences en phase gazeuse. Initialement, des électrodes à base de nanoparticules métalliques (Cu, Fe, Pt, Ru, Co) déposées sur des nanotubes de carbone ou du noir de carbone ont été étudiées pour leur capacité de réduction du CO2. L'ordre relatif de productivité dans la réduction électrocatalytique de CO2 dans ces séries d'électrodes a été trouvé différent entre les cellules en phase gazeuse et en phase liquide indiquant les différentes voies de réaction. Pour les conditions de phase liquide, en termes de produits C nets, les électrodes catalytiques à base de Pt sont en tête de la catégorie, suivies de près par Ru et Cu, tandis que Fe a obtenu la position la plus basse. Le mécanisme réactionnel sous-jacent probable a également été fourni. Afin d'améliorer encore les performances de la réduction du CO2 dans les conditions de phase liquide, une étude de la nanoparticules métalliques (NPs) dépendant de la taille de la réduction électro-catalytique du CO2 aux combustibles a été réalisée. Ceci a été réalisé à l'aide d'électrodes à base de nanoparticules métalliques (Ru, Fe, Pt et Cu) chargées sur les nanotubes de carbone (CNT) transférés sur les couches de diffusion gazeuse (GDL). On a synthétisé des nanoparticules de métal de différentes tailles en utilisant différentes techniques de synthèse: (i) l'itinéraire d'imprégnation pour obtenir des NP dans la plage de tailles de 10 à 50 nm; (Ii) Approche organométallique pour synthétiser des NPs uniformes et ultrafines dans la plage de tailles de 1-5 nm. Fe ont été synthétisés par une nouvelle voie de synthèse et des conditions pour atteindre des NP de 1 à 3 nm. (Iii) Approche de haut en bas de Nanowire pour obtenir des NP métalliques de cuivre ultrafin dans la plage de taille de 2-3,8 nm. En particulier, la nouveauté de l'aide de nanofils est la capacité à obtenir des particules de très petite taille d'abord la synthèse du Cu NFs, puis de les mettre en contact avec le support carboné et de faciliter son transfert, cela grâce à des forces d'attraction intermoléculaires des groupes fonctionnels présent sur le CNT partiellement oxydée. En outre, contrairement à la synthèse organométallique, cette approche permet d'effectuer les réactions dans l'air et non pas dans une atmosphère inerte. Les améliorations de la productivité du combustible ont été trouvées être au moins 5 à 30 fois plus élevées pour les NP métalliques de plus petite taille obtenus par voie organo-métallique ou par nanofil, par rapport aux NP métalliques plus grands obtenus par voie d'imprégnation. Les résultats indiquent que les NP métalliques de plus petite taille chargés sur les CNT jouent un rôle prédominant dans la performance catalytique et la sélectivité vis-à-vis de différents produits. En outre, le pourcentage de charge de NP métalliques a été réduit de façon significative de 10% à 1-2% en poids, produisant des carburants plus élevés ou équivalents pour de petites NP en comparaison avec les NP plus grandes. De plus, comme on a observé clairement la productivité en H2 qui a augmenté de nombreux facteurs pour les NP plus petits sur les plus grandes NP. La réutilisabilité des électrodes de travail et les longs temps de réaction ont également été sondés. Un ensemble différent d'électrodes à base de nano-mousses sur des feuilles métalliques a également été étudié afin d'obtenir des améliorations beaucoup plus importantes de l'électro-réduction de CO2 aux carburants. Ces nano-mousses ou dendrites ont été préparées par une technique de dépôt électrochimique. Des études d'optimisation sur le dépôt de ces mousses ont été effectuées initialement pour fixer l'ensemble des conditions de préparation. De plus, une étude d'optimisation de la tension a été réalisée en utilisant la voltamétrie cyclique et des tests de réduction de CO2 complets pour fixer une tension optimale pour les réactions. Les électrodes nano-mousses testées incluent (mousses Cu, Fe sur feuille Cu, feuille Fe, feuille Al, feuille Inconel et grille Al). Les améliorations de la productivité du combustible pour diverses mousses se situaient dans la plage de 2 à 10 fois par rapport à la productivité nette de combustible la plus élevée obtenue en utilisant des électrodes catalytiques en carbone dopé par des NP métalliques. Différentes caractérisations et outils d'analyse ont été utilisés pour analyser les catalyseurs qualitativement et quantitativement qui incluent la microscopie électronique à transmission (TEM), la microscopie électronique à balayage (SEM), la spectroscopie d'absorption atomique (AAS), la diffraction des rayons X (XRD) La spectroscopie électronique (XPS) et Brunauer-Emmett-Teller (BET) et pour déterminer les productivités des combustibles, chromatographie ionique (IC), chromatographie gazeuse-spectromètre de masse (GC-MS), chromatographie gazeuse.

Abstract Fruit trees require six macronutrients (N, P, K, calcium, Mg and sulfur) and eight micronutrients (Zn, Fe, B, Mn, Cu, chlorine, nickel and molybdenum) that are taken up through the roots. Many of these occur naturally in the soil as cations bound to negatively charged soil particles, while others are dissolved in the liquid surrounding the soil particles in the form of anions. This chapter discusses the uptake and assimilation of nutrient resources in fruit trees. Tabulated data are given on mean annual N, P and K storage (kg/ha) in perennial organs of mature almond trees that received N fertilizer at 309 kg/ha.

Abstract A novel friction sintering process is used to obtain large copper foam plates using sintering and dissolution process. The process ensures easy and quick removal of the sintered product. Heat and pressure generated by downfeed of rotating tungsten tool pressed against a “top plate” results in solid-state sintering of copper powder particles. The large sized sintered part was obtained by providing a scan path for tool covering the “die” containing Cu-NaCl mixture. Note that no pre-compression of Cu-NaCl is done before the start of the process. Compaction and sintering both happen during the course of friction sintering. Scanning electron microscopy (SEM) images of fracture surface indicate that pore morphology is dictated by the morphology of NaCl particles. Temperature increases with the increase in plunge depth. The stress-strain curves for obtained foam in compression are similar to the reported in.

Abstract Data centers housing high performance computing equipment have large and growing rack densities, which pushes the limits of traditional air cooling technologies because of limited heat transfer coefficients. Therefore, on-chip cooling using so-called cold plates is emerging as a necessary cooling option for high-density electronics. The use of mini-channels or pins fins to enhance internal heat transfer area inside cold plates requires extensive micro-machining that is relatively time consuming and expensive for mass production. As an alternative approach, inserting and bonding pre-manufactured metal foams into hollow bodies are explored as a potentially inexpensive means to enhance the interior heat transfer area of cold plates. One key aspect of the performance of metal foams in cold plates is the thermal contact resistance in the bonding between the foam and the substrate. This project predicts the contact resistance using measurements of different foam types (pure Cu and Cu with oxide), porosities (63%, 80%, 93%, and 95%) and thicknesses (4 mm, 8 mm, and 10 mm). These measurements are carried out with and without the use of thermal interface material (TIM) pads. A theory is proposed and implemented to estimate the contact and foam thermal resistances, but further work is needed to gain confidence in the results. Observations suggest that different thermal behavior is seen for the Cu foams compared to the Cu with oxide foams, and that the use of TIM pads can achieve 10x to 40x reduction in overall thermal resistance for highly porous foams bonded on Cu substrates.

Volcanogenic massive-sulfide (VMS) deposits may have had metal contributions from magmatic degassing and leaching of footwall rocks. The Windy Craggy Cu-Co-Zn VMS deposit in northwestern British Columbia may include magmatic contributions, based on laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of fluid inclusions (enriched in Sb, Sn, and Bi) and lithogeochemistry. Sulfide-mineral trace-element abundances in the massive-sulfide orebody, underlying stockwork zone, gold zone, and altered and unaltered mafic rock and argillite were analyzed by LA-ICP-MS. Elevated Au, W, As, Bi, Sb, Se, Te, Tl, Ag, Co, and Mo contents occur within the gold and/or stockwork zones. Increasing 'magmatic metals' with increasing Co/Ni values suggest direct magmatic contribution to the deposit. Covariation of Co with these so-called 'magmatic elements' indicates that it, too, may be of magmatic origin, sourced via fluids exsolved from a crystallizing magma; however, evidence from the composition of rocks and sulfide minerals from Windy Craggy and other VMS deposits suggests that there is probably no meaningful distinction between hydrothermal leaching and direct magmatic contributions and that most - if not all - fluids that form VMS deposits should be termed 'magmatic-hydrothermal'.

The Geo-mapping for Energy and Minerals (GEM) and Targeted Geoscience Initiative (TGI) programs conducted extensive collaborative research on mineral systems with iron oxide-copper-gold (IOCG) and affiliated deposits in prospective settings of Canada. Regional alteration mapping as well as geochemical and geophysical modelling undertaken under the GEM program documented the evolution of polymetallic metasomatic systems with iron-oxide and alkali-calcic alteration and led to an increased recognition of the mineral potential of poorly explored areas and historic deposits of the Great Bear magmatic zone in the Northwest Territories, thus providing a solid framework for exploration. Early and barren albitite corridors form across the mineral systems and locally host uranium mineralization associated with telescoping of alteration facies by tectonic activity during the metasomatic growth of the systems. Subsequent to albitization, high-temperature Ca-Fe and Ca-K-Fe alteration form iron oxide-apatite (± rare-earth element) mineralization and IOCG variants rich in cobalt and other critical metals, respectively. Systems that further mature to K-Fe alteration form IOCG mineralization and can evolve to mineralized near-surface phyllic alteration and epithermal caps. Transitional facies also host polymetallic skarn mineralization. Rare-earth element enrichments within iron oxide-apatite zones are strongest where remobilization has occurred, particularly along deformation zones. The TGI projects documented the pertinence for a GEM activity in the Great Bear magmatic zone and subsequently synthesized GEM geoscientific data into a system-scale, ore-deposit model, and outlined criteria for mineral resource assessment. This model, and newly developed field-mapping and lithogeochemical tools were shown to be efficient mineral exploration and regional mapping methods in Canada and were also applied to the archetype IOCG deposit, Olympic Dam, and other deposits in the Olympic Cu-Au metallogenic province of Australia. Case examples also include the Romanet Horst in the Trans-Hudson Orogen (second phase of GEM), the Central Mineral Belt in Labrador (TGI), the Wanapitei Lake district in Ontario (private sector exploration results used by TGI), and the Bondy gneiss complex in Quebec (TGI).

The overall goal of this project was to elucidate the role of dissolved organic matter (DOM) in soil retention, bioavailability and plant uptake of silver and cerium oxide NPs. The environmental risks of manufactured nanoparticles (NPs) are attracting increasing attention from both industrial and scientific communities. These NPs have shown to be taken-up, translocated and bio- accumulated in plant edible parts. However, very little is known about the behavior of NPs in soil-plant system as affected by dissolved organic matter (DOM). Thus DOM effect on NPs behavior is critical to assessing the environmental fate and risks related to NP exposure. Carbon-based nanomaterials embedded with metal NPs demonstrate a great potential to serve as catalyst and disinfectors. Hence, synthesis of novel carbon-based nanocomposites and testing them in the environmentally relevant conditions (particularly in the DOM presence) is important for their implementation in water purification. Sorption of DOM on Ag-Ag₂S NPs, CeO₂ NPs and synthesized Ag-Fe₃O₄-carbon nanotubebifunctional composite has been studied. High DOM concentration (50mg/L) decreased the adsorptive and catalytic efficiencies of all synthesized NPs. Recyclable Ag-Fe₃O₄-carbon nanotube composite exhibited excellent catalytic and anti-bacterial action, providing complete reduction of common pollutants and inactivating gram-negative and gram-positive bacteria at environmentally relevant DOM concentrations (5-10 mg/L). Our composite material may be suitable for water purification ranging from natural to the industrial waste effluents. We also examined the role of maize (Zeamays L.)-derived root exudates (a form of DOM) and their components on the aggregation and dissolution of CuONPs in the rhizosphere. Root exudates (RE) significantly inhibited the aggregation of CuONPs regardless of ionic strength and electrolyte type. With RE, the critical coagulation concentration of CuONPs in NaCl shifted from 30 to 125 mM and the value in CaCl₂ shifted from 4 to 20 mM. This inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (&gt; 10 kDa) reduced the aggregation most. RE also significantly promoted the dissolution of CuONPs and lower MW fraction (&lt; 3 kDa) RE mainly contributed to this process. Also, Cu accumulation in plant root tissues was significantly enhanced by RE. This study provides useful insights into the interactions between RE and CuONPs, which is of significance for the safe use of CuONPs-based antimicrobial products in agricultural production. Wheat root exudates (RE) had high reducing ability to convert Ag+ to nAg under light exposure. Photo-induced reduction of Ag+ to nAg in pristine RE was mainly attributed to the 0-3 kDa fraction. Quantification of the silver species change over time suggested that Cl⁻ played an important role in photoconversion of Ag+ to nAg through the formation and redox cycling of photoreactiveAgCl. Potential electron donors for the photoreduction of Ag+ were identified to be reducing sugars and organic acids of low MW. Meanwhile, the stabilization of the formed particles was controlled by both low (0-3 kDa) and high (&gt;3 kDa) MW molecules. This work provides new information for the formation mechanism of metal nanoparticles mediated by RE, which may further our understanding of the biogeochemical cycling and toxicity of heavy metal ions in agricultural and environmental systems. Copper sulfide nanoparticles (CuSNPs) at 1:1 and 1:4 ratios of Cu and S were synthesized, and their respective antifungal efficacy was evaluated against the pathogenic activity of Gibberellafujikuroi(Bakanae disease) in rice (Oryza sativa). In a 2-d in vitro study, CuS decreased G. fujikuroiColony- Forming Units (CFU) compared to controls. In a greenhouse study, treating with CuSNPs at 50 mg/L at the seed stage significantly decreased disease incidence on rice while the commercial Cu-based pesticide Kocide 3000 had no impact on disease. Foliar-applied CuONPs and CuS (1:1) NPs decreased disease incidence by 30.0 and 32.5%, respectively, which outperformed CuS (1:4) NPs (15%) and Kocide 3000 (12.5%). CuS (1:4) NPs also modulated the shoot salicylic acid (SA) and Jasmonic acid (JA) production to enhance the plant defense mechanisms against G. fujikuroiinfection. These results are useful for improving the delivery efficiency of agrichemicals via nano-enabled strategies while minimizing their environmental impact, and advance our understanding of the defense mechanisms triggered by the NPs presence in plants.