A La^3+-Cu/Pt modified electrode was fabricated by electrodepositing process in CuS04 solution by adding a small amount of lanthium compound, and it was employed for direct current (DC) amperometric detection of sp...A La^3+-Cu/Pt modified electrode was fabricated by electrodepositing process in CuS04 solution by adding a small amount of lanthium compound, and it was employed for direct current (DC) amperometric detection of spectinomycin by anion-exchange chromatography. Without derivatization, this method can simultaneously determine the main component and impurities in spectinomycin pharmaceutical raw material. Ease of preparation, being applied in DC detection mode and good catalytic stability confirmed the interests of this modified electrode as amperometric sensor for the determination of spectinomycin.展开更多
Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the ...Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon(TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.展开更多
Al(OH)_3 modified nickel slag adsorbent was prepared by sintering technology. The structure of the sample was characterized by BET, XRD, IR, SEM and EDAX. The sample's adsorption performance of Pb^(2+) and Cu^(...Al(OH)_3 modified nickel slag adsorbent was prepared by sintering technology. The structure of the sample was characterized by BET, XRD, IR, SEM and EDAX. The sample's adsorption performance of Pb^(2+) and Cu^(2+) from aqueous solution was studied. Results indicated that the adsorbent is a loose and porous mesoporous material. Its surface had mass aluminosilicate, high-activity γ-Al_2O_3 and its p H ranges from 4 to 12 that all have negative charges. The BET surface of the adsorbent is 23.90 m^2/g. Furthermore, its surface contains rich oxygenic functional groups, which could not only provide abundant adsorption sites for Pb^(2+) and Cu^(2+), but also improve the adsorption performance of Pb^(2+) and Cu^(2+) from waste water through the complexation of heavy metal ions. The best p H values selected in the adsorption of Pb^(2+) and Cu^(2+) are 6 and 5, respectively. With the increase of the initial concentration of simulated solution, the adsorption capacities of Pb^(2+) and Cu^(2+) gradually increased but the removal rates showed a downward trend. The competitive adsorption results of Pb^(2+) and Cu^(2+) showed that Pb^(2+) has better preferential adsorption than Cu^(2+).展开更多
Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to i...Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.展开更多
Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for f...Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.展开更多
基金supported by National Natural Science Foundation of China(No.20775070)Zhejiang Provincial Natural Science Foundation of China(No.Y407153)sponsored by Zhejiang Provincial Assay Foundation of China(No.2007F70017)
文摘A La^3+-Cu/Pt modified electrode was fabricated by electrodepositing process in CuS04 solution by adding a small amount of lanthium compound, and it was employed for direct current (DC) amperometric detection of spectinomycin by anion-exchange chromatography. Without derivatization, this method can simultaneously determine the main component and impurities in spectinomycin pharmaceutical raw material. Ease of preparation, being applied in DC detection mode and good catalytic stability confirmed the interests of this modified electrode as amperometric sensor for the determination of spectinomycin.
文摘Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon(TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.
基金Supported by the National Natural Science Foundation of China(Nos.51102047&51472050)
文摘Al(OH)_3 modified nickel slag adsorbent was prepared by sintering technology. The structure of the sample was characterized by BET, XRD, IR, SEM and EDAX. The sample's adsorption performance of Pb^(2+) and Cu^(2+) from aqueous solution was studied. Results indicated that the adsorbent is a loose and porous mesoporous material. Its surface had mass aluminosilicate, high-activity γ-Al_2O_3 and its p H ranges from 4 to 12 that all have negative charges. The BET surface of the adsorbent is 23.90 m^2/g. Furthermore, its surface contains rich oxygenic functional groups, which could not only provide abundant adsorption sites for Pb^(2+) and Cu^(2+), but also improve the adsorption performance of Pb^(2+) and Cu^(2+) from waste water through the complexation of heavy metal ions. The best p H values selected in the adsorption of Pb^(2+) and Cu^(2+) are 6 and 5, respectively. With the increase of the initial concentration of simulated solution, the adsorption capacities of Pb^(2+) and Cu^(2+) gradually increased but the removal rates showed a downward trend. The competitive adsorption results of Pb^(2+) and Cu^(2+) showed that Pb^(2+) has better preferential adsorption than Cu^(2+).
基金supported by the Climate Change Response Project (NRF-2019M1A2A2065612)the Brainlink Project (NRF2022H1D3A3A01081140)+3 种基金the NRF-2021R1A4A3027878 and the No. RS-2023-00212273 funded by the Ministry of Science and ICT of Korea via National Research Foundationresearch funds from Hanhwa Solutions Chemicals (1.220029.01)UNIST (1.190013.01)supported by the Institute for Basic Science (IBS-R019-D1)。
文摘Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.
基金This work was supported by the following projects:INTERNATIONAL COOPERATION Projects of the Ministry of Science and Technology(2014DFE60170)the Strategic Japanese-Swiss Science and Technology Program from the Swiss National Science Foundation(project No.IZJSZ2_180176)+4 种基金the Sino-Swiss Science and Technology Cooperation(SSSTC)2016 project from the Swiss National Science Foundation(project No.IZLCZ2_170294)the National Natural Science Foundation of China(Grant No.61674084)the Overseas Expertise Introduction Project for DisciplineInnovation of Higher Education of China(Grant No.B16027)Tianjin Science and Technology Project(Grant No.18ZXJMTG00220)the Fundamental Research Fund for the Central Universities of China.
文摘Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.