Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode m...Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.展开更多
Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which ...Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive understanding.Herein,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a precursor.Experimental and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)O.At−0.6 V(vs.reversible hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).展开更多
Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples ac...Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal structure.XRD results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,respectively.The shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the nanoparticles.The transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host material.The energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.展开更多
A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutrali...A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutralization reaction between Cu(OH)_(2)and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in-situ-formed hydroxides and raise the local basicity.Remarkably,the optimal Nafionactivated Cu(OH)_(2)-derived Cu can efficiently suppress the hydrogen evolution reaction(HER)and improve the selectivity for multi-carbon products in the CO_(2)electroreduction reaction(eCO_(2)RR).The H2 Faradaic efficiency(FE)decreased to 11%at a current density of 300 mA/cm2(−0.76 V vs.RHE)in a flow cell,while the bare one with H2 had an FE of 40%.The total eCO_(2)RR FE reaches as high as 83%,along with an evidently increased C2H4 FE of 44%as compared with the bare one(24%),and good stability(8000 s),surpassing that of most of the reported Cu(OH)_(2)-derived Cu.The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO_(2)RR as acquired by felicitously introducing ionomer on the Cu(OH)_(2)-derived Cu surface.展开更多
Cu（OH）2 nanowires were prepared and incorporated into poly（vinylidene fluoride）（PVDF） to fabricate Cu（OH）2-PVDF ultrafiltration（UF） membrane via immersion precipitation phase inversion process. The effect of...Cu（OH）2 nanowires were prepared and incorporated into poly（vinylidene fluoride）（PVDF） to fabricate Cu（OH）2-PVDF ultrafiltration（UF） membrane via immersion precipitation phase inversion process. The effect of Cu（OH）2 nanowires on the morphology of membranes was investigated by X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared（FTIR） spectroscopy, atomic force microscopy（AFM）, scanning electron microscopy（SEM） and X-ray diffraction（XRD） measurements. The results showed that all the Cu（OH）2-PVDF membranes had wider fingerlike pore structure and better hydrophilicity, smoother surface than pristine PVDF membrane due to the incorporation of Cu（OH）2 nanowires. In addition, water flux and bovine serum albumin（BSA） rejection were also measured to investigate the filtration performance of membranes. The results indicated that all the Cu（OH）2-PVDF membranes had high water flux, outstanding BSA rejection and excellent antifouling properties. It is worth mentioning that the optimized performance could be obtained when the Cu（OH）2 nanowires content reached 1.2 wt%. Furthermore, the membrane with 1.2 wt% Cu（OH）2 nanowires showed outstanding oil-water emulsion separation capability.展开更多
基金The authors wish to acknowledge financial support from the Science and Technology Projects in Jilin Province Department of Education(Grant No.JJKH20220239KJ).
文摘Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.
基金Scientific Research Project in Anhui Jianzhu University(No.2023QDZ04).
文摘Electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NH_(3))offers a viable approach for sustainable NH_(3)production and environmental denitrification.Copper(Cu)possesses a distinctive electronic structure,which can augment the reaction kinetics of NO_(3)^(−)and impede hydrogen evolution reaction(HER),rendering it a promising contender for the electrosynthesis of NH_(3)from NO_(3)^(−).Nevertheless,the role of Cu_(2)O in copper-based catalysts still requires further investigation for a more comprehensive understanding.Herein,the Cu_(2)O/Cu(OH)_(2)heterostructures are successfully fabricated through liquid laser irradiation using CuO nanoparticles as a precursor.Experimental and theoretical researches reveal that Cu_(2)O/Cu(OH)_(2)heterostructure exhibits enhanced electrocatalytic performance for NO_(3)^(−)to NH_(3)because Cu(OH)_(2)promotes electron transfer and reduces the valence state of Cu active site in Cu_(2)O.At−0.6 V(vs.reversible hydrogen electrode(RHE)),the NH_(3)yield reaches its maximum at 1630.66±29.72μg·h^(−1)·mgcat^(−1),while the maximum of Faraday efficiency(FE)is 76.95%±5.51%.This study expands the technical scope of copper-based catalyst preparation and enhances the understanding of the electrocatalytic mechanism of NO_(3)^(−)to NH_(3).
文摘Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal structure.XRD results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,respectively.The shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the nanoparticles.The transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host material.The energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.
基金National Natural Science Foundation of China,Grant/Award Numbers:52201227,21972126,51872209,52072273Zhejiang Provincial Special Support Program for High-level Talents,Grant/Award Number:2019R52042Key Project of Zhejiang Provincial Natural Science Foundation,Grant/Award Number:LZ20B030001。
文摘A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutralization reaction between Cu(OH)_(2)and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in-situ-formed hydroxides and raise the local basicity.Remarkably,the optimal Nafionactivated Cu(OH)_(2)-derived Cu can efficiently suppress the hydrogen evolution reaction(HER)and improve the selectivity for multi-carbon products in the CO_(2)electroreduction reaction(eCO_(2)RR).The H2 Faradaic efficiency(FE)decreased to 11%at a current density of 300 mA/cm2(−0.76 V vs.RHE)in a flow cell,while the bare one with H2 had an FE of 40%.The total eCO_(2)RR FE reaches as high as 83%,along with an evidently increased C2H4 FE of 44%as compared with the bare one(24%),and good stability(8000 s),surpassing that of most of the reported Cu(OH)_(2)-derived Cu.The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO_(2)RR as acquired by felicitously introducing ionomer on the Cu(OH)_(2)-derived Cu surface.
基金financially supported by the Postdoctoral Science Foundation of China (No.2014M560802)the Natural Science Foundation of Education Department of Shaanxi Provincial Government (No.16JK1755)the State Key Laboratory of Chemical Engineering (No.SKL-ChE-16A04)
文摘Cu（OH）2 nanowires were prepared and incorporated into poly（vinylidene fluoride）（PVDF） to fabricate Cu（OH）2-PVDF ultrafiltration（UF） membrane via immersion precipitation phase inversion process. The effect of Cu（OH）2 nanowires on the morphology of membranes was investigated by X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared（FTIR） spectroscopy, atomic force microscopy（AFM）, scanning electron microscopy（SEM） and X-ray diffraction（XRD） measurements. The results showed that all the Cu（OH）2-PVDF membranes had wider fingerlike pore structure and better hydrophilicity, smoother surface than pristine PVDF membrane due to the incorporation of Cu（OH）2 nanowires. In addition, water flux and bovine serum albumin（BSA） rejection were also measured to investigate the filtration performance of membranes. The results indicated that all the Cu（OH）2-PVDF membranes had high water flux, outstanding BSA rejection and excellent antifouling properties. It is worth mentioning that the optimized performance could be obtained when the Cu（OH）2 nanowires content reached 1.2 wt%. Furthermore, the membrane with 1.2 wt% Cu（OH）2 nanowires showed outstanding oil-water emulsion separation capability.
