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Spin‐polarized density functional theory (DFT) +U calculation was performed to study propylene selective oxidation on Cu2O(111) and Cl−Cu2O(111) surfaces. The mechanism included two pathways: the allylic hydrogen stripping (AHS) pathway and the epoxidation pathway, and acrolein, propylene oxide (PO), propanal and acetone can be formed. The calculated results found that the C3H6*+OO*→OOMMP2*→PO* route can be regarded as the preferred formation route of PO on these two surfaces. On clean surface, acrolein can be regarded as the main product, then other products selectivity follows: acetone>PO>propanal. On Cl−Cu2O(111) surface, acrolein was also the main product, and the apparent activation energy of acrolein (1.97 eV) was approximated to the apparent activation energy of PO (2.04 eV), other products selectivity follows: PO>propanal>acetone, which means that the selectivity of PO can be improved by the effect of Cl. Microkinetic simulation confirm that PO selectivity can be elevated qualitatively, and found that OOMMP2*→PO2*+O* is the rate determining step on pure surface and C3H6*+OO*→OOMMP2* is the rate controlling step on the doped−Cl surface. From this work, it can be found the O−O bond in O2 can be activated effectively by the presence of Cl, enhancing the selectivity of PO. [ABSTRACT FROM AUTHOR]

In this work, a composite material for the adsorption removal of thiophenic sulfur compounds (TSCs) was prepared by loading Cu2O onto palygorskite using a simple and low‐cost impregnation method and characterized for its structure and morphology. The addition of Cu2O did not change palygorskite's structure, and the Cu+ was evenly dispersed in the palygorskite fibers. The palygorskite provided the adsorptive active centers Cu+ efficient surface and pore structure to increase the sulfur removal performance of palygorskite. The optimum desulfurization process conditions of the Cu2O/palygorskite were obtained experimentally and by response surface methodology. With solid/liquid mass ratio of 1/100 and temperature of 30°C, the maximum static adsorption capacity of the Cu2O/palygorskite in model oil, which was composed of n‐octane and a single TSC at 400 mg S/L, showed an increase of 639% for thiophene, 543% for benzothiophene, and 563% for dibenzothiophene compared to palygorskite alone. In addition, the pseudo‐second‐order kinetic and Langmuir isotherm model exhibited the most fitting results for thiophene adsorbing on the composite, indicating that chemisorption on a monolayer basis plays a key role in the adsorption process. To sum up, these results suggest the composite has some potential in the field of adsorption‐desulfurization materials. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) nanoplates are synthesised using the Co-precipitation method. The prepared nanoplates is confirmed by using XRD and optical properties was determined by UV-Vis DRS and the direct bandgap was done using Tauc's plot. The band gap values determined for Cu2O nanoplates around 1.69 eV, which is clearly on the visible region. The using TEM image determined the morphology of the prepared Cu2O nanoplates, the observed result was plate like shape. The photocatalytic degradation of Methylene Blue was carried out in visible light. The adsorption was carried out in the dark for 30 min before photodegradation. The MB degradation efficiency for Control and Cu2O nanoplates were 5.1 and 70%, respectively. The MB Degradation efficiency for Cu2O nanoplates for the 13.7 times better degradation rate than without catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] Production of C 2 chemicals (such as C 2 H 4 , C 2 H 5 OH, etc.) from CO 2 electroreduction reaction (CO 2 ER) has been regarded as a promising route to solve the environmental problems and energy crisis. In this work, mesoporous Cu 2 O microspheres of ca. 700 nm diameter size with low crystallinity were fabricated to enable efficient conversion of CO 2 to C 2 chemicals by electrocatalytic reduction. It is revealed that compared with bulk Cu 2 O, the obtained mesoporous Cu 2 O microspheres have larger surface area, more grain boundaries and defects (unsaturated coordination sites), which facilitate the adsorption and stabilization of the important intermediates, such as *CO, on the route to C 2 chemicals formation. As a result, the Faraday efficiency (FE) of C 2 products reaches as high as 82.6 % and 78.5 % in an H-cell and a flow cell, respectively. In situ Raman and FT-IR spectra reveal that during CO 2 ER test there exists abundant *CO on the mesoporous Cu 2 O surface, thus increasing the opportunity of C C coupling. And the high coverage of *CO on catalyst surface during CO 2 ER protects and stabilizes the oxidation state of Cu species. This work demonstrates an effective strategy to introduce mesoporous structures and decreased crystallinity for improving the performance of CO 2 ER to C 2 products. [ABSTRACT FROM AUTHOR]

We report herein the analysis of the properties of copper(I) oxide thin films deposited by an optimized ammonium-free successive ion layer adsorption and reaction (SILAR) technique. The Cu2O thin film deposition process was carried out at room temperature using copper acetate monohydrate, sodium citrate as complexing agent, and hydrogen peroxide as precursors of copper and oxygen ions, respectively. The harmless and easy-to-handle sodium citrate replaces the volatile NH4OH commonly employed as complexing agent in the SILAR technique for the deposition of metal oxide thin films. The optical, structural, morphological, and electrical properties of the as-deposited Cu2O thin films were studied as a function of the number of cycles during deposition, as well as their modifications produced by the effect of rapid thermal annealing (RTA) in vacuum in a temperature range of 200–250°C for 1 min, 3 min, and 5 min. The as-deposited thin films had cubic crystalline structure corresponding to the Cu2O phase as determined by x-ray diffraction (XRD), with a direct energy bandgap of 2.43–2.51 eV depending on the number of cycles, and electrical resistivity of the order of 103 Ω cm. The XRD and x-ray photoelectron spectroscopy (XPS) analysis of the Cu2O thin films treated by RTA demonstrated an increase of the crystal size with time and temperature of the RTA and reduction effects from Cu2+ to Cu1+ oxidation states. On the other hand, the RTA treatments also decreased their energy bandgap to 2.38 eV and electrical resistivity to 102 Ω cm. The high energy bandgap values of the Cu2O thin films were attributed to quantum confinement effects produced by their small crystal size in the range of 3.6–8.6 nm. [ABSTRACT FROM AUTHOR]

In this study, we employed the one-dimensional solar cell capacitance simulator (SCAPS-1D) software to optimize the performance of Pb-based and Sn-based (Pb-free) all-inorganic perovskites (AIPs) and organic–inorganic perovskites (OIPs) in perovskite solar cell (PSC) structures. Due to the higher stability of AIPs, the performance of PSCs incorporating Cs-based perovskites was compared with that of FA-based perovskites, which are more stable than their MA-based counterparts. The impact of AIPs such as CsPbCl3, CsPbBr3, CsPbI3, CsSnCl3, CsSnBr3, and CsSnI3, as well as including FAPbCl3, FAPbBr3, FAPbI3, FASnCl3, FASnBr3, and FASnI3, was investigated. SnO2 and Cu2O were selected as an inorganic electron transport layer (ETL) and a hole transport layer (HTL), respectively. CsSnBr₃, CsSnI₃, FASnCl₃, and FASnBr₃ exhibited higher efficiency compared to their Pb-based counterparts. Additionally, most Cs-based perovskites, excluding CsPbI₃, demonstrated better performance relative to their FA counterparts. CsSnI3 AIP device also shows the highest short circuit current density (JSC) of 32.85 mA/cm2, the best power conversion efficiency (PCE) of 16.00%, and the least recombination at the SnO2/CsSnI3 interface. The thickness, doping, and total defect density of CsSnI3 PSC have been systematically investigated and optimized to obtain the PCE of 17.36%. These findings highlight the potential of CsSnI3 PSCs as efficient and environmentally friendly PSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu 2 O@ZnTPP nanosheet heterojunction is prepared for photocatalytic CO 2 RR to CH 4. • Cu 2 O@ZnTPP exhibits ∼ 4 and ∼ 10 times CH 4 evolution rate than ZnTPP and Cu 2 O. • CH 4 selectivity is improved from ∼ 62 % of Cu 2 O and ∼ 90 % of ZnTPP to ∼ 99 %. • Zn-O-Cu bond between Cu 2 O and ZnTPP is proved to be a key for catalytic activity. • The fsTA spectra confirm the photoinduced electron transfer from ZnTPP to Cu 2 O. The application of supermolecular naonostructures in the photocatalytic carbon dioxide reduction reaction (CO 2 RR) has attracted increasing attentions. However, it still faces significant challenges, such as low selectivity for multi-electron products and poor stability. Here, the cuprous oxide (Cu 2 O)-modified zinc tetraphenylporphyrin ultrathin nanosheets (ZnTPP NSs) are successfully constructed through the aqueous chemical reaction. Comprehensive characterizations confirm the formation of type-II heterojunction between Cu 2 O and ZnTPP in Cu 2 O@ZnTPP, and the electron transfer from Cu 2 O to ZnTPP through the Zn-O-Cu bond under the static contact. Under the visible-light irradiation (λ > 420 nm), the optimized Cu 2 O@ZnTPP sample as catalyst for photocatalytic CO 2 RR exhibits the methane (CH 4) evolution rate of 120.9 μmol/g/h, which is ∼ 4 and ∼ 10 times those of individual ZnTPP NSs (28.0 μmol/g/h) and Cu 2 O (12.8 μmol/g/h), respectively. Meanwhile, the CH 4 selectivity of ∼ 98.7 % and excellent stability can be achieved. Further experiments reveal that Cu 2 O@ZnTPP has higher photocatalytic conversion efficiency than Cu 2 O and ZnTPP NSs, and the photoinduced electron transfer from ZnTPP to Cu 2 O can be identified via the path of ZnTPP→ (ZnTPP•ZnTPP)*→ ZnTPP-→ Zn-O-Cu → Cu 2 O. Consequently, Cu 2 O@ZnTPP exhibits a shorter electron-hole separation lifetime (3.3 vs. 9.3 ps) and a longer recombination lifetime (23.1 vs. 13.4 ps) than individual ZnTPP NSs. This work provides a strategy to construct the organic nanostructures for photocatalytic CO 2 RR to multi-electron products. [ABSTRACT FROM AUTHOR]

Cu2O homojunction solar cells were fabricated using potentiostatic electrodeposition technique. n-Cu2O thin films were grown in an acetate bath while p-Cu2O thin films were grown in a lactate bath. In the growth of n-Cu2O films, cupric acetate concentration, pH and temperature of the bath, deposition potential and duration (film thickness) and annealing temperature were investigated. In the growth of p-Cu2O on n-Cu2O, concentration of copper sulphate and lactic acid solutions, pH and temperature of the bath, deposition potential and duration were investigated. In addition, the procedure of sulfidation of p-Cu2O film surface using (NH4)2S vapor, before depositing Au front contact, was also optimized to enhance the photoactive performance. The structural, morphological and optoelectronic properties of the Cu2O films were investigated using scanning electron microscopy (SEMs), high energy X-ray diffraction (HEXRD), hard X-ray photoelectron spectroscopy (HAXPES), spectral response and current–voltage (J-V) measurements. The best Cu2O homojunction solar cell exhibited Voc = 460 mV, Jsc = 12.99 mA·cm−2, FF = 42% and η = 2.51%, under AM 1.5 illumination. Efficiency enhancement with the record high Jsc value for the Cu2O homojunction solar cell has mainly been due to the optimization of pH of the n-Cu2O deposition bath and lactic acid concentration of the p-Cu2O deposition bath. [ABSTRACT FROM AUTHOR]

The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction, but also their ability to form key intermediates with reactant molecules. The present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-coated Cu2O/Cu (Cu2O/Cu/N-C) with a Cu2O/dual electron acceptor interface using etched HKUST-1 as the precursor. A series of theoretical and experimental studies have demonstrated that the Cu2O/Cu/N-C interface in the photocatalytic homo-coupling of terminal alkynes not only effectively enhances the separation of photogenerated electron–hole pairs, but also facilitates the formation of the key intermediate [Cu2O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal charges. As a result, the homo-coupling reaction can be effectively facilitated. The primary reason for the functional role of Cu2O/Cu/N-C interface lies in the downward bending of energy band from Cu2O to N-doped C layers, induced by the different work functions of Cu2O, Cu and N-doped C layers. Consequently, Cu2O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-coupling reaction of terminal alkynes under blue-light irradiation and air atmosphere. The present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications. [ABSTRACT FROM AUTHOR]

Optimizing the photocatalytic efficiency of semiconductor materials is capable of being achievable by the effective tuning of the interfacial transport efficiency of photogenerated carriers utilizing crystal facet engineering. This study adopted a liquid deposition routine tackle to generate cubic, truncated octahedral, and octahedral Cu2O crystals with various exposed facets. Afterward, a Cu2O/g-C3N4 heterojunction was constructed exploiting defective g-C3N4 as a carrier. By controlling the exposed facet, the work function difference between Cu2O and g-C3N4 was adjusted, resulting in an enhanced built-in electric field and greater photogenerated carrier transit via the Cu2O/g-C3N4 heterojunction interface. The OCN heterojunction, which is composed of g-C3N4 and octahedral Cu2O with a {111} facet, revealed the highest photocatalytic degradation effectiveness of tetracycline (90.8%), which exceeded the values of pure octahedral Cu2O and g-C3N4 by 1.26 and 1.75 times, respectively, as determined by photocatalytic activity experiments. Z-scheme heterojunction among g-C3N4 and octahedral Cu2O has been verified through UPS, XPS, EIS, and transient photocurrent response analysis, along the direction of the built-in electric field recognized between them. In contrast, OCN displayed the highest photocatalytic activity due to its Z-scheme heterojunction, which evidently promoted the separation efficiency of photogenerated carriers. This research proposes an innovative approach for regulating the exposed facet of semiconductors and augmenting the inherent electric field strength of heterojunctions, culminating in the efficient photocatalytic degradation of tetracycline. [ABSTRACT FROM AUTHOR]

[Display omitted] The efficacy of electron-hole separation in a single sonosensitizer and the complexities of the tumor microenvironment (TME) present significant challenges to the effectiveness of sonodynamic therapy (SDT). Designing efficient sonosensitizers to enhance electron-hole separation and alleviate TME resistance is crucial yet challenging. Herein, we introduce a novel Z-scheme heterojunctions (HJs) sonosensitizer using Fe-doped carbon dots (CDs) as auxiliary semiconductors to sensitize cubic Cu 2 O (Fe-CDs@Cu 2 O) for the first time. Fe-CDs@Cu 2 O demonstrated enhanced SDT effects due to improved electron-hole separation. Additionally, the introduction of Fe ions in CDs synergistically enhances Fenton-like reactions with Cu ions in Cu 2 O, resulting in enhanced chemodynamic therapy (CDT) effects. Moreover, Fe-CDs@Cu 2 O exhibited rapid glutathione (GSH) depletion, effectively mitigating TME resistance. With high rates of 1O 2 and OH generated by Fe-CDs@Cu 2 O, coupled with strong GSH depletion, single drug injection and ultrasound (US) irradiation effectively eliminate tumors. This innovative heterojunction sonosensitizer offers a promising pathway for clinical anti-tumor treatment. [ABSTRACT FROM AUTHOR]

In this study, coloured Ni/Cu2O bilayer films were electrochemically deposited on large area automobile plastic parts (7 × 13 cm) for decorative applications. Such coatings may become an alternative to ubiquitously used Cr coatings for plastics. Purple, dark cyan and gold colours with good homogeneity and high brightness could be produced by tuning the deposition time of the Cu2O layer. Colouration of the bilayer film can be ascribed to interference of light through the metal/dielectric layer, where the thickness of the dielectric layer controls the wavelength of the reflected light. Cu2O film has a compact structure and low roughness, which is essential to obtain uniform colours. Moreover, the Ni/Cu2O bilayer exhibits good adhesion behaviour, environmental stability and enhanced corrosion resistance. This process is industrially viable and enables the large scale production of such decorative coatings. [ABSTRACT FROM AUTHOR]

Semiconducting Cu2O have excellent optical and electronic properties and are more promising candidates for advanced electronic applications. In the current study, pure and 3.125%, 6.25%, and 12.5% Zn doped Cu2O compositions were studied using density functional theory in the framework of wien2k-code. Experimentally, uniform and smooth thin films of these compositions were successfully synthesized through the spin coating technique. The elemental composition and morphology were studied using energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy, respectively. Crystallographic analysis of thin films shows a cubic phase structure having space-group 224 Pn-3m. The total density of states confirms the overlapping of states at the Fermi level for Zn-doped compositions. The significant variations in thermoelectric parameters observed with change of temperature for pure and Zn substituted Cu2O compositions, especially the Seebeck-coefficient values vary from 2.5 × 10−4 to 5.5 × 10−5 VK−1 for these cuprous oxide compositions. The optical-parameter such as absorption and extinction coefficient curves reached maxima at the highest photon energies. The enhancement in transmittance power and reduction in the band gap energy from 2.08 eV to 1.75 eV with the substitution of Zn material enhanced the availability of these compositions for advanced applications. Highlights: DFT calculations of Zn substituted Cu2O compositions. Phase pure growth of uniform and smooth thin films. Cubic phase detected having space-group 224 Pn-3m. A significant variation was observed in thermoelectric and optical properties. Band gap was reduced from 2.08 eV to 1.75 eV with substitution of Zn. [ABSTRACT FROM AUTHOR]

In this study, copper oxide nanoparticles have been produced utilizing a high-purity copper target and a conventional laser system with two separate pulsed laser wavelengths (1064 and 532 nm), which have not been explored in previous works. Physical properties of these wavelengths have been studied. Measurements were made of the particle size, shape, and size distributions. XRD (X-ray diffraction) analyses indicated that the nanofilms were deposited at 1064 nm and are cubic structures with discrimination along the (110) direction. Transmission electron microscopy (TEM) was used to examine nanoparticles with sizes ranging from 76 to 57.5 nm. UV spectroscopy was utilized to determine the optical characteristics of the colloidal solution. The material seems to have a modest UV-VIS spectrum. The flour peak is around 590 nm, which indicates the formation of Cu2O nanoparticles. The indirect bandgap (2.36–2.2 eV), respectively, exhibits a pronounced red shift. These nanoparticles are most likely the result of quantum confinement processes at nanoscales. [ABSTRACT FROM AUTHOR]

It is expected that the activity of photocatalysts can remain the same or decrease as little as possible in photocatalysis reaction. Herein, for the first time, a self‐accelerating H2 production activity in a noble‐metal‐free Cu2O/TpPa‐2‐COF photocatalyst is reported. It shows a beginning H2 production rate of 4.41 mmol h−1 g−1 under visible light illuminance, while the activity kept increasing to 27.27 mmol h−1 g−1 after 25 h reaction, which is 6.2 times higher than the beginning activity and reaches a record high. It is confirmed that part of Cu2O in Cu2O/TpPa‐2‐COF in situ transformed to Cu0 in photocatalytic reaction, which acting as cocatalyst promotes the separation of photogenerated charge carriers. Further density functional theory calculations demonstrate that the Schottky barrier height of Cu‐Cu2O (111) interface is much smaller than that of Pt‐Cu2O (111), supporting its more efficient effect than that with Pt as cocatalyst. [ABSTRACT FROM AUTHOR]

The insight of the activity phase and reaction mechanism is vital for developing high-performance ammonia synthesis electrocatalysts. In this study, the origin of the electronic-dependent activity for the model Cu2O catalyst toward ammonia electrosynthesis with nitrate was probed. The modulation of the electronic state and oxygen vacancy content of Cu2O was realized by doping with halogen elements (Cl, Br, I). The electrocatalytic experiments showed that the activity of the ammonia production depends strongly on the electronic states in Cu2O. With increased electronic state defects in Cu2O, the ammonia synthesis performance increased first and then decreased. The Cu2O/Br with electronic defects in the middle showed the highest ammonia yield of 11.4 g h−1 g−1 at −1.0 V (vs. RHE), indicating that the pattern of change in optimal ammonia activity is consistent with the phenomenon of volcano curves in reaction chemistry. This work highlights a promising route for designing NO3−RR to NH3 catalysts. [ABSTRACT FROM AUTHOR]

Cu2O has emerged as a promising material for sustainable hydrogen production through photoelectrochemical (PEC) water splitting, while inefficient charge separation remains one of the main challenges hindering its development. In this work, a new architecture of InAlN/Cu2O heterojunction photocathode is demonstrated by combining n‐type InAlN and p‐type Cu2O to improve the charge separation efficiency, thus enhancing PEC water‐splitting performance. The Pt/InAlN/Cu2O photoelectrode exhibits a photocurrent density of 2.54 mA cm−2 at 0 V versus reversible hydrogen electrode (VRHE), which is 3.21 times higher than that of Cu2O (0.79 mA cm−2 at VRHE). The enhanced PEC performance is explained by the larger built‐in potential Vbi of 1.43 V formed at the InAlN/Cu2O p–n junction than that in the single Cu2O photocathode (Vbi < 0.77 V), which improves the separation of the photogenerated carriers and thus relieves the bottlenecks of charge‐transfer kinetics at the electrode bulk and electrode/electrolyte interface. In this work, an avenue is opened for designing III‐nitrides/Cu2O heterojunction toward solar energy conversion. [ABSTRACT FROM AUTHOR]

Copper-based materials play a vital role in the electrochemical transformation of CO2 into C2/C2+ compounds. In this study, cross-sectional octahedral Cu2O microcrystals were prepared in situ on carbon paper electrodes via electrochemical deposition. The morphology and integrity of the exposed crystal surface (111) were meticulously controlled by adjusting the deposition potential, time, and temperature. These cross-sectional octahedral Cu2O microcrystals exhibited high electrocatalytic activity for ethylene (C2H4) production through CO2 reduction. In a 0.1 M KHCO3 electrolyte, the Faradaic efficiency for C2H4 reached 42.0% at a potential of −1.376 V vs. RHE. During continuous electrolysis over 10 h, the FE (C2H4) remained stable around 40%. During electrolysis, the fully exposed (111) crystal faces of Cu2O microcrystals are reduced to Cu0, which enhances C-C coupling and could serve as the main active sites for catalyzing the conversion of CO2 to C2H4.

Currently, n-type cuprous oxide (Cu2O) is a promising material as photocatalyst because of its energy gap of 2 eV that absorbs visible light up to a wavelength of 600 nm. As a photoelectrode, the thickness of Cu2O is crucial, where the improper thickness may worsen the photocatalytic properties. This work aimed to enhance the photocatalytic properties of Cu2O electrodeposited on fluorine-doped tin oxide (FTO), called Cu2O/FTO, by optimizing the Cu2O thickness. The thickness of Cu2O was controlled by adjusting the deposition time in the electrochemical deposition of Cu2O/FTO. By changing the deposition time from 5 to 45 min, the morphology of Cu2O changed from a leaf-like shape to an irregular facet shape with highly dense coverage, and the average thickness increased from 370 to 1100 nm. The increasing Cu2O thickness resulted in the increasing light absorption. The Cu2O/FTO demonstrated anodic photocurrent, which increased with the Cu2O thickness up to a threshold value of 1000 nm (35 min deposition time). At a thickness of 1000 nm, Cu2O/FTO achieved the highest photocurrent (150 and 58 µA under irradiation of 365 and 470 nm, respectively) due to the highly dense morphology and high absorption. In addition, with a thickness of 1000 nm, the charge diffusion was still good. Further, the increase of Cu2O film thickness higher than 1000 nm caused low photocatalytic properties even though the morphology was highly dense, and the absorption was the highest. This condition could be due to the relatively too-high resistance of Cu2O that caused poor charge diffusion. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Copper-based chalcogenide quaternary semiconductors have emerged as promising candidates for next-generation photovoltaic (PV) devices, owing to their unique electronic and photonic properties coupled with environmentally friendly compositions. This study explores the potential of copper-based absorber materials, specifically Cu2FeSnS4 (CFTS), as an absorber in heterojunction solar cells with Cu-/Ni-metal oxides back surface field (BSF) and SnS2 buffer layers using the SCAPS-1D Simulator. Initially, we assess the performance of CFTS-absorber solar cells and compare the key photovoltaic metrics with those of other Cu-based semiconductors including CuInxGa(1-x)Se2 (CIGS), Cu2ZnSnS4 (CZTS), Cu2CoSnS4 (CCTS), Cu2NiSnS4 (CNTS), Cu2BaSnS4 (CBTS), Cu2MnSnS4 (CMTS), to identify the most promising absorber. Subsequently, we optimize the layer properties, including active layer thickness, free-carrier concentration, bulk and interface defect density, and carrier recombination in potential CFTS. Further, we examine the impact of defects, and carrier recombination, including radiative, Shockley-Read-Hall (SRH), and Auger recombination. These detailed studies yield improved and competitive photoconversion efficiency, (PCE) of 27.31% (compared to 24.68%, without BSF) with open circuit voltage, (VOC) of 1.36 V, short-circuit current density, (JSC) of 22.28 mA/cm² and fill factor, (FF) of 90.47% for Cu2O, whereas the PCE of 26.97% with VOC of 1.07 V, JSC of 28.82 mA/cm² and FF of 86.91% for NiOx BSF layer in Au/Mo/BSF(Cu2O and NiOx)/CFTS/SnS2/ZnMgO/ZnO:Al/Pt configurations under optimized conditions. The enhanced charge separation and carrier collection efficiencies reveal the strong potential of CFTS absorber heterostructures with Cu2O/NiOx, SnS2, and bi-layer ZnMgO/ZnO:Al as BSF, buffer, and window layers, repectively, providing insights and resources for developing high-efficiency CFTS-based photovoltaic devices.

Currently, n-type cuprous oxide (Cu2O) is a promising material as photocatalyst because of its energy gap of 2 eV that absorbs visible light up to a wavelength of 600 nm. As a photoelectrode, the thickness of Cu2O is crucial, where the improper thickness may worsen the photocatalytic properties. This work aimed to enhance the photocatalytic properties of Cu2O electrodeposited on fluorine-doped tin oxide (FTO), called Cu2O/FTO, by optimizing the Cu2O thickness. The thickness of Cu2O was controlled by adjusting the deposition time in the electrochemical deposition of Cu2O/FTO. By changing the deposition time from 5 to 45 min, the morphology of Cu2O changed from a leaf-like shape to an irregular facet shape with highly dense coverage, and the average thickness increased from 370 to 1100 nm. The increasing Cu2O thickness resulted in the increasing light absorption. The Cu2O/FTO demonstrated anodic photocurrent, which increased with the Cu2O thickness up to a threshold value of 1000 nm (35 min deposition time). At a thickness of 1000 nm, Cu2O/FTO achieved the highest photocurrent (150 and 58 µA under irradiation of 365 and 470 nm, respectively) due to the highly dense morphology and high absorption. In addition, with a thickness of 1000 nm, the charge diffusion was still good. Further, the increase of Cu2O film thickness higher than 1000 nm caused low photocatalytic properties even though the morphology was highly dense, and the absorption was the highest. This condition could be due to the relatively too-high resistance of Cu2O that caused poor charge diffusion. [ABSTRACT FROM AUTHOR]

The threat of ozone in indoor spaces and other enclosed environments is receiving increasing attention. Among numerous ozone catalytic decomposition technologies, copper catalytic material has a superior performance and relatively low cost, making it one of the ideal catalyst materials. This review presents the recent Cu catalyst studies on ozone decomposition, particularly morphological design, the construction of heterostructures, and monolithic catalyst design used to improve their performance. Moreover, this review proposes further improvement directions based on Cu materials' inherent limitations and practical needs. On this basis, in the foreseeable future, Cu materials will play a greater role. [ABSTRACT FROM AUTHOR]

In this study, using high-purity copper targets, copper oxide nanoparticles have been obtained using a traditional laser system with low laser fluence, which has not been considered in other works. Physical properties of these fluences have been studied. The current study shows the construction and analysis of Cu2O NPs and characterizes their performance. Nd:YAG laser ablation in DW at various fluences (6.3–8.91–11.46–14.01–16.56) J/cm2 was used to construct the Cu2O layer at a laser wavelength of 1064 nm. Cu2O nanoparticles (NPs) were studied using transmission electron microscopy (TEM), which revealed that their semi-spherical morphologies and average particle size ranged from (63–55) nm, depending on the laser fluences. All of the samples of Cu2O NPs that were analyzed by XRD had a Cube crystal structure, as expected. Measurements of UV–VIS and photoluminescence showed that raising the laser energy caused the absorption and emission wavelengths of Cu2O NPs to shift to red. Cu2O NPs' optical energy gap was varied from (2–1.97) eV in response to changes in laser fluence. [ABSTRACT FROM AUTHOR]

In this study, various factors affecting the efficiency of the MAPbI3 perovskite solar cell (PSC) were analyzed using the SCAPS-1D simulation program. The basic device analyzed in this study had a structure of ITO/TiO2/MAPbI3/Cu2O/Au. The thickness of each layer (electron transport layer (ETL), perovskite absorption layer (PAL), and hole transport layer (HTL)), PAL defect density and interface defect density were investigated as parameters. The optimized parameters that yielded the highest light conversion efficiency were an ETL (TiO2) thickness of 100 nm, a PAL (MAPbI3) thickness of 1300 nm, an HTL (Cu2O) thickness of 400 nm, a PAL defect density of 1014 cm−3, and an interface defect density of 1013 cm−3 for both absorber/ETL and absorber/HTL interfaces. The optimized PSC exhibited a maximum efficiency of 19.30%. These results obtained in this study are expected to contribute considerably to the optimization and efficiency improvement of perovskite solar cells using inorganic charge-carrier transport layers. [ABSTRACT FROM AUTHOR]

• Cu 2 O with different morphologies was applied for H 2 O 2 activation. • The cubic Cu 2 O showed the highest activity for TC degradation. • The surface oxygen species play an important role for H 2 O 2 adsorption. • Hydroxyl radicals, carbonate radicals and Cu(III) were the main active species. • Possible TC degradation mechanism was proposed. The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems (BAP) is a hot topic in wastewater treatment. In this work, Cu 2 O nanoparticles with different morphologies including cubic shape (c-Cu 2 O), octahedron shape (o-Cu 2 O) and spherical shape (s-Cu 2 O), were applied in BAP for the first time to degrade tetracycline hydrochloride (TC). Compared with Cu2+ ions and CuO, TC degradation was boosted in the presence of Cu 2 O in the BAP system, with the degradation rate following the order c-Cu 2 O > o-Cu 2 O > s-Cu 2 O. The morphology-dependent effects could be linearly correlated with the ratio of surface oxygen species (O S), but not with the surface area or Cu(I) ratio. The c-Cu 2 O catalyst with exposure of (100) facets contained 76.6% O S as the active site for H 2 O 2 adsorption and activation, while the value was much lower for o-Cu 2 O and s-Cu 2 O with dominant (111) facets. The presence of HCO 3 − enhanced the interactions among Cu 2 O, H 2 O 2 and TC, leading to facile oxidation of Cu(I) to Cu(II) by H 2 O 2 , and the formation of various reactive species such as hydroxyl radicals and Cu(III) contributed to TC degradation. This work provides a new method for enhancing H 2 O 2 activation with heterogeneous catalysts by crystal facet engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

Based on the "Electrolysis-Gasometric Determination of Avogadro's Constant" experiment offered to freshmen, an integrated experiment was designed for the electrochemical synthesis of Cu2O and determination of Avogadro's constant by aerometry. This experiment ingeniously integrates the preparation and property study of Cu2O from elemental chemistry experiments. A single electrolytic process accomplishes two experiments, save both electricity and time. The integrated experiment can be flexibly interspersed within the foundational chemistry experiment curriculum in universities. It holds great significance for cultivating students' holistic thinking, multi-faced problem-solving abilities, as well as the concepts of economic and environmental conservation. [ABSTRACT FROM AUTHOR]

The production of hydrogen fuel using photoelectrochemical water splitting method requires semiconductor materials with suitable energy gap, electrical and optical properties. Cuprous oxide is feasible candidate fulfilling many of these requirements to be the photocathode of such devices. In this study, we investigated optical and microstructural properties of cuprous oxide prepared under different temperatures. Microstructure properties were evaluated by statistical, fractal and Fourier methods. Roughness characteristics, Fourier transforms and multifractal characteristics provide consistent information connected with the distribution of surface objects created during sample fabrication. Our methodology is feasible to provide practical insights for the fabrication and monitoring of surface and optical properties of Cu2O and other semiconductor materials. [ABSTRACT FROM AUTHOR]

To develop persulfate (PS) activation for effective treatment of water containment was meaningful and important. Cuprous oxide (Cu2O) was an abundant, cheap metal-oxide material, has attracted much attention for various fields. In this work, the Cu2O was used to activate PS via the oxidative disproportionation process of electron migration. Meanwhile, the redox disproportionation process would affect the PS activation. To overcome this troublesome. Here, a Schottky junction of Ag/Cu2O composite was designed to affect electronic transmission by in-situ decorated process with biomass materials in mild condition. The Ag/Cu2O/PS exhibited highly efficient activity for tetracycline (TC) degradation by PS activation, the 95% of TC was removed within 30 min, which was 1.84 times higher than Cu2O/PS system. Besides, the response surface methodology (RSM) was used to determine the relationship of pH values, TC concentration and PS dosage for TC degradation. The optimal pH value, TC concentration and PS dosage was selected as 7.0, 30 mg/L and 300 mg/L, respectively. The trapping experiments demonstrated the ‧OH and SO4.− radicals took part in the degradation process and the relative contribution of each radial was calculated. This work would provide new insight to develop efficiency by PS activation. [ABSTRACT FROM AUTHOR]

Copper (Cu) is evidenced to be effective for constructing advanced catalysts. In particular, Cu2O is identified to be active for general catalytic reactions. However, conflicting results regarding the true structure‐activity correlations between Cu2O‐based active sites and efficiencies are usually reported. The structure of Cu2O undergoes dynamic evolution rather than remaining stable under working conditions, in which the actual reaction cannot proceed over the prefabricated Cu2O sites. Therefore, the dynamic construction of Cu2O active sites can be developed to promote catalytic efficiency and reveal the true structure‐activity correlations. Herein, by introducing the redox pairs of Cu2+ and reducing sugar into a photocatalysis system, it is clarified that the Cu2O sub‐nanoclusters (NCs), working as novel active sites, are on‐site constructed on the substrate via a photoinduced pseudo‐Fehling's route. The realistic interfacial charge separation and transformation capacities are remarkably promoted by the dynamic Cu2O NCs under the actual catalysis condition, which achieves a milestone efficiency for nitrate‐to‐ammonia photosynthesis, including the targets of production rate (1.98±0.04 mol gCu−1 h−1), conversion ratio (94.2±0.91 %), and selectivity (98.6 %±0.55 %). The current work develops an effective strategy for integrating the active site construction into realistic reactions, providing new opportunities for Cu‐based chemistry and catalysis sciences research. [ABSTRACT FROM AUTHOR]

The present work describes the effect of deposition temperatures and pH values on structural, morphological, and electrochemical properties of cuprous oxide (Cu2O) thin films deposited on the conductive SnO2 glass substrates by using electrodeposition technique in an acidic system. The chronoamperometry curve of the solution was tested on an electrochemical workstation. X-ray diffraction patterns indicate that the deposited films have better crystallinity which is deposited at the deposition temperature of 50 °C and pH value of 5–6. Scanning electron microscopy displays that surface morphology of the deposited films varied greatly with the deposition temperature and pH value rising. The results of quantitative study of the target product films by Energy Dispersive Spectrometer (EDS) show that they are all in line with the element content ratio of Cu2O. By measuring the resistivity and conductivity of the deposited films, it was found to be in the semiconductor range. [ABSTRACT FROM AUTHOR]

CuO/Cu2O/Cu ternary composites were prepared using a Cu metal-organic framework (MOF) and melamine as raw materials using a simple calcination process. The ultraviolet and visible light catalytic properties of the CuO/Cu2O/Cu composites were evaluated through methylene blue (MB) degradation. Results show that a ternary CuO/Cu2O/Cu composite was obtained when a single Cu-MOF was calcined in air. The Cu and Cu2O in the product decreased as the melamine in the raw material increased. CuO/Cu2O/Cu composites have excellent photocatalytic properties with the aid of H2O2. When the melamine in the raw material was 15%, the photocatalytic performance of the composite material was the best. With the aid of H2O2, MB was almost completely degraded under ultraviolet and visible light irradiation for 3 and 20 min, respectively. [ABSTRACT FROM AUTHOR]

In this study, Cu2O particles was synthesis by using chemical reduction method. The XRD, FTIR, SEM and UV-Visible spectroscopy were utilised to characterise the synthesised Cu2O particles. The observed data matches previously reported XRD data of Cu2O particles (JCPDS File number 01-075-1531), confirming the fabrication of pure phase particles. The crystallite size of the synthesised Cu2O particles is 39.91 nm was calculating by using Scherrer formula. The band gap of synthesised Cu2O was measured at 1.91 eV using UV-Vis. Morphology and topography were identified using SEM investigation, illustrating development. FTIR analysis confirmed the functional group of particles. The experimental variables related to Cu2O particles photocatalytic methylene blue (MB) dye degradation. The measured MB degradation efficiency was 58.27%, at 10 ppm dye concentration, 60 min reaction duration, and 10 mg catalyst dosage. Effective adsorption and photocatalytic elimination of typical organic pollutants (MB) were proven by the Blue LED. The understanding of Cu2O-based photocatalyst design for organic pollutants degradation. [ABSTRACT FROM AUTHOR]

Photovoltaics is the third-largest renewable energy source in the world today due to its popularity; however, thin-film solar cells are currently replacing PV due to material limitations in large-scale applications. These cells must be developed from widely accessible, fairly cost-effective, and environmentally benign materials. Silica nanoparticles derived from rice husk (SiO2np) and doped Cu2O thin films were examined for solar cell applications. A nebulizer spray technique was used to deposit SiO2np of 0.25, 0.5, 0.75, 1, and 1.25 wt% onto Cu2O. The electrical, optical, and microstructural properties of the deposited thin films were studied. The presence of SiO2np in the Cu2O phase was observed in the XRD spectrum. The structural, optical, and electrical properties of SiO2np: Cu2O thin films were highly affected by SiO2np doping. The energy bandgap and optical transmittance are reduced with a rise in SiO2np doping. An 84.61% and 98.85% increment in mobility and carrier concentration and a 33.87% and 72.72% decrease in band gap and resistivity were obtained at 1.25 w% SiO2np:Cu2O. It was established that SiO2np:Cu2O thin films produced 0.480% power conversion efficiency and 0.30 V open-circuit voltage. [ABSTRACT FROM AUTHOR]

Coatings on copper, zinc and stainless-steel substrates were fabricated using the plasma electrolytic oxidation (PEO) technique and their photocatalytic activity was evaluated in the reduction of Cr(VI), a highly toxic agent present in wastewater from industrial processes such as electroplating, manufacture of textile dyes, wood curing, and leather tanning. The concentration of hexavalent chromium in drinking water has been regulated to a maximum value established by national and international legislation of 0.05 ppm. The strategy of reduction to less toxic species such as Cr(III), followed by its precipitation in a basic medium, use several methods derived from chemistry, physics and biology for the treatment of water contaminated with this material. In the present work, some coatings of copper, zinc, and iron oxides were obtained over the corresponding metal sheets exposed to PEO, which were tested in a heterogeneous process of advanced oxidation with 1 ppm Cr(VI) solution under ultraviolet radiation. Thus, a reduction rate to Cr(III) close to 100% in 60 min was obtained. [ABSTRACT FROM AUTHOR]

Polymeric films composed of polyvinyl alcohol (PVA) with different percents of CeO2 and Cu2O were prepared using casting method to form PVA/(x) Cu2O (15-x) CeO2 composite at doping concentrations of (0, 1, 5, 7.5, 10, and 15 wt%). The addition of CeO2 and Cu2O affect the structural, morphological, vibrational, and optical properties of PVA film. The lattice parameters of the films were measured. PCC7 film with 15% Cu2O and 0% CeO2 in PVA polymer-matrix, is a suitable candidate to be utilized in UV-shielding for solar cell applications, because of its capability of blocking UV between 190 and 230 nm. The optical energy gap of films varies between 4.77 and 3.32 eV for the indirect transitions and between 4.84 and 3.83 eV for the direct transitions, hence the PCC5 with 7.5% Cu2O and 7.5% CeO2 has the lowest values of direct and indirect energy gaps, which attributed to the enhancement of electronic transitions correlated to the equal ratio of p type Cu2O and n type CeO2 doping. The average value of the refractive index nav was measured according to different approaches. Also, the nonlinear refractive index n2 was measured, it was found that PCC5 has the largest value of nav and n2. [ABSTRACT FROM AUTHOR]

Individual (FTO/Cu2O and FTO/CuCo2O4) and heterostructured (FTO/BiVO4/Cu2O, FTO/BiVO4/CuCo2O4, and FTO/CuCo2O4/Cu2O) electrodes were successfully formed using the electrodeposition method on copper-containing compounds. The morphology of the synthesized electrode systems, which affect the electrochemical properties, was determined. A comparative study of the electrochemical and photoelectrochemical properties of the individual and heterostructured electrodes showed that the modification of the BiVO4 electrode surface with Cu2O and CuCo2O4 oxides led to a significant increase in its efficiency as a photoanode. The deposition of Cu2O nanoclusters onto CuCo2O4 nanoflakes increased the electrochemical stability of the electrode while maintaining its high capacitance. [ABSTRACT FROM AUTHOR]

[Display omitted] Some very effective antimicrobial coatings exploit copper or cuprous oxide (Cu 2 O) as the active agent. The aim of this study is to determine which species is the active antimicrobial – dissolved ions, the Cu 2 O solid, or reactive oxygen species. Copper ions were leached from Cu 2 O into various solutions and the leachate tested for both dissolved copper and the efficacy in killing Pseudomonas aeruginosa. The concentration of copper species leached from Cu 2 O into aqueous solution varied greatly with the composition of the aqueous solution. For a range of solution buffers, killing of P. aeruginosa was highly correlated with the concentration of copper in the leachate. Further, 10 µL bacterial suspension droplets were placed on Cu 2 O coatings, with or without a polymer barrier layer, and tested for bacterial kill. Killing occurred without contact between bacterium and solid, demonstrating that contact with Cu 2 O is not necessary. We therefore conclude that soluble copper species are the antimicrobial agent, and that the most potent species is Cu+. The solid quickly raises and sustains the concentration of soluble copper species near the bacterium. Killing via soluble copper ions rather than contact should allow copper coatings to kill bacteria even when fouled, which is an important practical consideration. [ABSTRACT FROM AUTHOR]

The optical properties of Cu2O nanowhiskers grown by the liquid method with material deposition in an electric field have been studied. The spectral lines forbidden by the selection rules for perfect Cu2O crystals were found in the Raman spectra. The nature of related phonon states is analyzed. In the photoluminescence spectra in the red and near-IR regions, broad bands of defective origin are observed. It was found that the presence of a band at 650 nm (1.9 eV) is a specific feature of the photoluminescence of nanowhiskers. Its properties are studied and possible radiation mechanisms are discussed. In the intrinsic absorption region of nanowhiskers, the photoluminescence band at 572 nm (2.17 eV) associated with band-band transitions is detected. At a low excitation level, the emission of a free exciton n = 1 of the yellow exciton series is observed with simultaneous emission of an optical phonon. [ABSTRACT FROM AUTHOR]