Direct conversion of carbon dioxide to multicarbon products remains as a grand challenge in electrochemical CO₂ reduction. Various forms of oxidized copper have been demonstrated as electrocatalysts ...that still require large overpotentials. Here, we show that an ensemble of Cu nanoparticles (NPs) enables selective formation of C₂–C₃ products at low overpotentials. Densely packed Cu NP ensembles underwent structural transformation during electrolysis into electrocatalytically active cube-like particles intermixed with smaller nanoparticles. Ethylene, ethanol, and n-propanol are the major C₂–C₃ products with onset potential at −0.53 V (vs. reversible hydrogen electrode, RHE) and C₂–C₃ faradaic efficiency (FE) reaching 50% at only −0.75 V. Thus, the catalyst exhibits selective generation of C₂–C₃ hydrocarbons and oxygenates at considerably lowered overpotentials in neutral pH aqueous media. In addition, this approach suggests new opportunities in realizing multicarbon product formation from CO₂, where the majority of efforts has been to use oxidized copper-based materials. Robust catalytic performance is demonstrated by 10 h of stable operation with C₂–C₃ current density 10 mA/cm² (at −0.75 V), rendering it attractive for solar-to-fuel applications. Tafel analysis suggests reductive CO coupling as a rate determining step for C₂ products, while n-propanol (C₃) production seems to have a discrete pathway.
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•Green synthesis of CuNPs by leaf extract of C. paniculatus.•CuNPs showed characteristic peak at 269 nm with particle size of 2−10 nm.•CuNPs Characterized via UV–vis spectroscopy, ...FT-IR, SEM-EDS, TEM, and DLS analysis.•Antifungal activity tested against F. oxysporum.•Photocatalytic degradation of organic dye methylene blue using CuNPs.
This research aimed to explore the eco-friendly green synthesis of copper nanoparticles (CuNPs) using Celastrus paniculatus leaves extract. Primarily, the biosynthesized CuNPs characterized by UV–vis spectroscopy showed an absorption peak at 269 nm. Further, The SEM and TEM studies revealed the spherical shape of particles with size ranged between 2−10 nm with an average particle diameter of 5 nm. FT-IR analysis confirmed the presence of functional groups OH, CC and CH triggers the synthesis of CuNPs. The negative zeta potential -22.2 mV indicated the stability of CuNPs was confirmed by DLS and the composition and purity by EDS studies. Further, the photocatalytic property of the CuNPs was divulged by their methylene blue dye degradation potential. The reaction kinetics followed pseudo-first-order with k-values (rate constant) 0.0172 min−1. In addition, this material was found to be a good antifungal agent against plant pathogenic fungi Fusarium oxysporum showed 76.29 ± 1.52 maximum mycelial inhibition.
To date, copper is the only monometallic catalyst that can electrochemically reduce CO2 into high value and energy‐dense products, such as hydrocarbons and alcohols. In recent years, great efforts ...have been directed towards understanding how its nanoscale structure affects activity and selectivity for the electrochemical CO2 reduction reaction (CO2RR). Furthermore, many attempts have been made to improve these two properties. Nevertheless, to advance towards applied systems, the stability of the catalysts during electrolysis is of great significance. This aspect, however, remains less investigated and discussed across the CO2RR literature. In this Minireview, the recent progress on understanding the stability of copper‐based catalysts is summarized, along with the very few proposed degradation mechanisms. Finally, our perspective on the topic is given.
The CO2 electroreduction reaction has recently gained in popularity. Cu is still the only monometallic catalyst that can effectively produce interesting molecules, such as hydrocarbons and alcohols. Many breakthroughs have been on the so‐called structure–activity/selectivity relationships. However, the stability of Cu‐based electrodes and nanoscale degradation mechanisms are still in their infancy.
•A cost effective and highly efficient method was devised for cotton treatments.•Presence of the trimetallic nanoparticles onto cotton fabric in one bath.•The resultant treated cotton fabric gives ...multifunctional properties.
A facile method, cost-effective and highly efficient with shortened-time operation was devised for unprecedented modification of cotton fabrics. This modification induced the formation of metallic and metal oxide nanoparticles within cotton fabrics in such a way that cotton samples loaded with AgNPs- or AgNPs/ZnONPs or AgNPs/ZnONPs/CuNPs respectively. Presence of the trimetallic nanoparticles concomitantly within microstructural features of cotton imparts durable antibacterial, UV protection and conductivity properties to yield ultimately cotton fabrics with multifunctional performance. The nanoparticles were formed and stabilized independently by Polymethylol compound (PMC) and functionalized polyethyleneimine (FPEI) as per one bath. The results obtained proved that the solution of these metal compounds are turned from colourless to yellow and black green colour up on addition of PMC or FPEI compound. It was found that UV–vis spectra display maximum surface plasmon peak of around 410–415 confirming the successful synthesis of AgNPs stabilized by PMC or FPEI chains. In addition, the results obtained indicated that the as formed nanoparticles are successfully deposited into the surface of cellulose fabrics and reveal changes in crystalline structure. Fabrics underwent structural changes during their treatments as per the designed practice exhibit multifunctional properties and manifold performance. The resultant treated cotton fabric gives good antibacterial properties event after 20 washing cycles additionally to the excellent ultra-violet properties and excellent electrical conductivity.
Nanocrystal (NC) morphology, which decides the number of active sites and catalytic efficiency, is strongly determined by the gases involved in synthesis, treatment, and reaction. Myriad ...investigations have been performed to understand the morphological response to the involved gases. However, most prior work is limited to low pressures, which is far beyond realistic conditions. A dynamic morphological evolution of palladium–copper (PdCu) NC within a nanoreactor is reported, with atmospheric pressure hydrogen at the atomic scale. In situ transmission electron microscopy (TEM) videos reveal that spherical PdCu particles transform into truncated cubes at high hydrogen pressure. First principles calculations demonstrate that the surface energies decline with hydrogen pressure, with a new order of γH‐001<γH‐110<γH‐111 at 1 bar. A comprehensive Wulff construction based on the corrected surface energies is perfectly consistent with the experiments. The work provides a microscopic insight into NC behaviors at realistic gas pressure and is promising for the shaping of nanocatalysts by gas‐assisted treatments.
In good shape: Deliberate surface faceting of palladium–copper alloyed nanocrystals was achieved by simple post‐synthetic treatment in atmospheric pressure hydrogen. Microscopic insight is provided for tailoring of the physical and chemical properties of catalytically significant palladium alloys.
•Cu-NPs diminish the Fusarium wilt severity and improve the plant growth.•Cu-NPs act as a growth promoter for tomato plants.•Cu-NPs could be used in soils where copper is deficient.
Both the ...effectiveness of copper nanoparticles (Cu-NPs) as a treatment for Fusarium wilt and the role of Cu-NPs in promoting tomato plant growth were studied. First, we evaluated the in vitro antifungal activity of Cu-NPs at different concentrations (0.1, 0.25, 0.5, 0.75, and 1.0 mg/mL) against Fusarium oxysporum f. sp. lycopersici (FOL). A strong inhibitory effect on mycelial FOL growth (67.3%) was observed with 0.5 mg/mL Cu-NPs compared to a commercial fungicide based on copper hydroxide, whose inhibitory effect was only 15.6%. Next, in in vivo experiments at the same concentration, Cu-NPs significantly diminished the symptoms of Fusarium wilt by 68 and 66.5% for incidence and severity, respectively. Moreover, the treatments with Cu-NPs increased the growth of tomato plants and particularly raised the chlorophyll content (from 19.3 to 28.6%). This is because Cu-NPs effectively deliver copper as a micronutrient for the plants, while the uncontrolled uptake of copper ions from the commercial fungicide (copper hydroxide) inhibits the healthy development of plants. Importantly, despite the principal function of Cu-NPs as a fungicide, Cu-NPs may be applied as fertilizer for tomato plants. Thus, the application of Cu-NPs effectively treats Fusarium wilt while promoting the growth of tomato plants. Therefore, these results suggest that copper nanomaterials may be used as both a source of micronutrients in cases of soil copper deficiency and as a fungicide. In terms of sustainability, this multifunctionality has the potential to positively impact the environment.
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•Efficient use of polymer waste as catalyst substrate.•Biopolymer coated sponge as host for synthesis of catalytic metal nanoparticles.•Reduction of environmental pollutants with high ...conversion rates.•Easy recovery of the catalyst and re-use.
In the present study, two catalysts based-on copper and nickel nanoparticles anchored on agarose-coated sponge (Cu-AG-sponge and Ni-AG-sponge) were prepared, respectively. Both catalysts were characterized by analytical techniques of thermogravimetric analysis energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). Spherical Cu and Ni nanoparticles on struts of AG-coated sponge were observed by FESEM and the samples’ elemental composition was confirmed by EDX technique. After characterization, the Cu-AG-sponge and Ni-AG-sponge catalysts were tested in 4-nitrophenol (4-NP) and methylene blue dye (MB) reduction in an aqueous medium. The reduction of the 4-NP to 4-aminophenol (4-AP) was achieved up to 95% using the NaBH4 reductant and Cu-AG-sponge and Ni-AG-sponge catalysts, respectively. Similarly, the rate of reduction of MB was faster for the Cu-AG-sponge as compared to the Ni-AG-sponge which was discussed based-on the catalyst morphology and other factors. The high rate of reactions for the 4-NP and MB reduction suggests that the Cu-AG-sponge and Ni-AG-sponge catalyst possess high catalytic efficiency, low cost and good reusability having the potential to be used in similar other reactions.
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•This review highlights current research using copper nanoparticles as catalyst.•Synthetic procedures in detail have been explained.•We have discussed the reactions including the ...mechanistic illustrations.•Synthetic scope is covered.
Copper nanoparticles have been explored as a new class of heterogeneous catalyst in various chemical transformations. This review surveys the most useful organic transformations which were carried out in the presence of copper nanoparticles as catalyst. Copper nanoparticle catalyzed reactions are advantageous over the conventional metal catalyzed reactions in terms of low catalyst loading, high atom economy, better yields, inexpensive, shorter reaction times and recyclability of the catalyst. From a mechanistic point of view, it has been shown that most of the transformations proceed via the formation of organometallic intermediates C-Cu-X during the interactions with copper nanoparticles.
In the present study copper nanoparticles (CuNPs) were prepared using Syzygium aromaticum (clove) bud extract through simple and eco-friendly green route. The synthesized nanoparticles were subjected ...to structural, morphological, optical and antimicrobial studies. The high crystalline nature of CuNPs with a face centered cubic phase is evident from the X-ray diffraction (XRD) pattern. Morphological studies were used to study the shape and size of the synthesized nanoparticles. Energy dispersive spectroscopy (EDS) attests the high intense metallic peak of copper (Cu) and low intense peaks of carbon (C), oxygen (O), chlorine (Cl) and phosphorus (P) elements due to the capping action of biomolecules of bud extract in CuNPs formation. The zeta (ζ) potential of the CuNPs attests the stability of the nanoparticles. Ultraviolet-visible (UV–vis) absorption spectrum shows the characteristic absorption peak of CuNPs. Fourier transform infrared spectroscopy (FTIR) analysis shows the presence of different functional groups at various positions. The antimicrobial activity was investigated against the selected pathogens using bio-CuNPs. The positive test results of zone of inhibitions of 8mm and 6mm were attained against Bacillus spp. and Penicillium spp., respectively.
Creating a sensor that can concurrently monitor multiple therapeutic drugs in complex media is a challenging yet essential endeavor. This study presents a novel biomolecule-free electrochemical ...platform for simultaneous and highly selective detection of methotrexate (MTR) and paracetamol (PRC) in various matrices, including pharmaceutical formulations, simulated blood samples, and water samples. The platform utilizes a multi-layered petal-shaped black phosphorous structure supported on 3D graphene, along with bio-synthesized copper nanoparticles (BP-3DGp@BCuN). Prior to the sensing study, the as-prepared BP-3DGp@BCuN nanocomposite was characterized using FESEM, EDX, FTIR, UV, XPS, Raman spectroscopy, BET, and XRD. Electrochemical studies of BP-3DGp@BCuN nanocomposite reveal a considerable enhancement of the current compared to pure BP or 3DGp. The petal-shaped black phosphorous comprising of 3DGp and BCuN provides a larger surface area, effective mass transport, and more active sites for the attachment of the target analytes that amplified the current signals and detection sensitivity. Furthermore, computational analysis proves that the BP-3DGp@BCuN nanocomposite has strong interaction with the target MTR and PRC compared to other modifiers. Under optimized conditions, the proposed sensing method shows a linear detection range of 0.05–70 µM and 0.5–210 µM with limit of detection (LOD) values of 0.045 nM and 0.36 nM, with high sensitivity of 37.40 and 14.94 μA μM−1 cm−2 for PRC and MTR respectively. The real-life application of the present sensor was examined in pharmaceutical formulations, simulated blood, and water samples.
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