N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to...N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to characterize.Limited understanding of doping-derived EDL structure hinders insight into the structure-performance relations and the rational design of high-performance materials.Thus,we analyzed the mass and chemical composition variation of EDL within electrochemical operation by electrochemical quartz crystal microbalance,in-situ X-ray photoelectron spectroscopy,and time-offlight secondary ion mass spectrometry.We found that N-doping triggers specifically adsorbed propylene carbonate solvent in the inner Helmholtz plane(IHP),which prevents ion rearrangement and enhances the migration of cations.However,this specific adsorption accelerated solvent decomposition,rendering rapid performance degradation in practical devices.This work reveals that the surface chemistry of electrodes can cause specific adsorption of solvents and change the EDL structure,which complements the classical EDL theory and provide guidance for practical applications.展开更多
A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated....A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated. The electrogeneration of O ·- 2 was only obtained at the Pt electrode in this medium system. The different electrochemical behaviour of O 2 at Pt electrode and Au electrode were explained in terms of the different adsorptions of DSAB, which was confirmed by quartz crystal microbalance(QCM). The frequency responses for the reduction of O 2 at Pt electrode and Au electrodes were compared by electrochemical quartz crystal microbalance(EQCM), suggesting that the electrogenerated O ·- 2 was adsorbed on the surface of the Pt electrode. The one-electron reduction of oxygen in this system was also confirmed by using chronocoulometry. The scavenging activities of two kinds of antioxidants(ascorbic acid and cysteine) were examined and compared.展开更多
基金the National Science Foundation for Excellent Young Scholars of China(21922815)the National Natural Science Foundation of China(22179139)+2 种基金the National Key Research and Development Program of China(2020YFB1505800)the Youth Innovation Promotion Association of CAS(2019178)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of the CAS(XDA21000000)。
文摘N-doped porous carbon has been extensively investigated for broad electrochemical applications.The performance is significantly impacted by the electrochemical double layer(EDL),which is material dependent and hard to characterize.Limited understanding of doping-derived EDL structure hinders insight into the structure-performance relations and the rational design of high-performance materials.Thus,we analyzed the mass and chemical composition variation of EDL within electrochemical operation by electrochemical quartz crystal microbalance,in-situ X-ray photoelectron spectroscopy,and time-offlight secondary ion mass spectrometry.We found that N-doping triggers specifically adsorbed propylene carbonate solvent in the inner Helmholtz plane(IHP),which prevents ion rearrangement and enhances the migration of cations.However,this specific adsorption accelerated solvent decomposition,rendering rapid performance degradation in practical devices.This work reveals that the surface chemistry of electrodes can cause specific adsorption of solvents and change the EDL structure,which complements the classical EDL theory and provide guidance for practical applications.
文摘A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated. The electrogeneration of O ·- 2 was only obtained at the Pt electrode in this medium system. The different electrochemical behaviour of O 2 at Pt electrode and Au electrode were explained in terms of the different adsorptions of DSAB, which was confirmed by quartz crystal microbalance(QCM). The frequency responses for the reduction of O 2 at Pt electrode and Au electrodes were compared by electrochemical quartz crystal microbalance(EQCM), suggesting that the electrogenerated O ·- 2 was adsorbed on the surface of the Pt electrode. The one-electron reduction of oxygen in this system was also confirmed by using chronocoulometry. The scavenging activities of two kinds of antioxidants(ascorbic acid and cysteine) were examined and compared.
