Derivative-extremum analysis(DEA) of j-E curves is a newly proposed method of half wave potential(E1/2) and activation feature extraction from steady-state voltammetry. Here, the DEA is demonstrated to be valid in the...Derivative-extremum analysis(DEA) of j-E curves is a newly proposed method of half wave potential(E1/2) and activation feature extraction from steady-state voltammetry. Here, the DEA is demonstrated to be valid in the full range of reversibility using numerical simulations with a derived universal electrode equation, providing a novel perspective of electrochemical kinetics in the reversibility domain. The results reveal that E1/2is a better choice of the reference potential instead of equilibrium potential(Eeq) in electrode equations, especially since Eeqis meaningless in an irreversible case. The equations referenced with standard potential, E1/2and Eeq, are summarized in three tables, and their applications in parameter determinations are specified. Finally, reversibility is proved to be a relative measure between kinetic slowness and mass transport of electroactive species, and the reversibility classifications are proposed according to the DEA feature in the reversibility domain. This work, based on the DEA principle, refines the electrode equation forms and generalizes their applicability in the full range of reversibility.展开更多
Nano-emulsion,a kinetically stable system of nanosized oil droplets in water has been numerously used as a medium for biological and medicinal processes.It is also used as a solubilizing medium for compounds or molecu...Nano-emulsion,a kinetically stable system of nanosized oil droplets in water has been numerously used as a medium for biological and medicinal processes.It is also used as a solubilizing medium for compounds or molecules that are insoluble or poorly soluble in aqueous medium in addition to its use as a penetration enhancer in dermatological processes.Ferrocene,a metallocene that is known to be quite insoluble in aqueous medium is liberally soluble in the prepared oil-in-water nano-emulsion.In this medium,ferrocene undergoes a quasi-reversible reaction process and its relevant electrochemical kinetic parameters such as the heterogeneous rate constant,ko,the formal redox potential,Eo,the half-wave potential,E1/2,the electron transfer coefficient,α,and its diffusion coefficient,D,are determined in this medium.These important electrochemical parameters including the observed current function have been used to formulate a plausible mechanism for the oxidation of ferrocene in the formulated nano-emulsion.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 52131003, 52170059, 51808526, 51727812)。
文摘Derivative-extremum analysis(DEA) of j-E curves is a newly proposed method of half wave potential(E1/2) and activation feature extraction from steady-state voltammetry. Here, the DEA is demonstrated to be valid in the full range of reversibility using numerical simulations with a derived universal electrode equation, providing a novel perspective of electrochemical kinetics in the reversibility domain. The results reveal that E1/2is a better choice of the reference potential instead of equilibrium potential(Eeq) in electrode equations, especially since Eeqis meaningless in an irreversible case. The equations referenced with standard potential, E1/2and Eeq, are summarized in three tables, and their applications in parameter determinations are specified. Finally, reversibility is proved to be a relative measure between kinetic slowness and mass transport of electroactive species, and the reversibility classifications are proposed according to the DEA feature in the reversibility domain. This work, based on the DEA principle, refines the electrode equation forms and generalizes their applicability in the full range of reversibility.
基金The author is grateful to the Department of Chemistry of Morgan State University for its support of this work.
文摘Nano-emulsion,a kinetically stable system of nanosized oil droplets in water has been numerously used as a medium for biological and medicinal processes.It is also used as a solubilizing medium for compounds or molecules that are insoluble or poorly soluble in aqueous medium in addition to its use as a penetration enhancer in dermatological processes.Ferrocene,a metallocene that is known to be quite insoluble in aqueous medium is liberally soluble in the prepared oil-in-water nano-emulsion.In this medium,ferrocene undergoes a quasi-reversible reaction process and its relevant electrochemical kinetic parameters such as the heterogeneous rate constant,ko,the formal redox potential,Eo,the half-wave potential,E1/2,the electron transfer coefficient,α,and its diffusion coefficient,D,are determined in this medium.These important electrochemical parameters including the observed current function have been used to formulate a plausible mechanism for the oxidation of ferrocene in the formulated nano-emulsion.
