A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOO...A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOOH,M=Fe,Co,Ni)as a model system,we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction(OER).Among the photoanodes with the three different electrocatalysts,the best OER activity,with a low-onset potential of∼1.01 VRHE,a high photocurrent density of 24.10 mA cm^(-2)at 1.23 VRHE,and a remarkable saturation photocurrent density of 38.82 mA cm^(-2),was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight(100 mW cm^(-2))in 1 M KOH electrolyte.The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport,provides a larger number of surface active sites,and results in higher OER activity,compared to other electrocatalysts.This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.展开更多
This paper is a report of an empirical study of the 'washback' effects of CET-4 on College English teaching and learning in three ordinary teachers' colleges. The results of the study show that, in the fir...This paper is a report of an empirical study of the 'washback' effects of CET-4 on College English teaching and learning in three ordinary teachers' colleges. The results of the study show that, in the first three and half terms, college English teachers can basically develop students' competence in listening, speaking, reading and writing under the guidance of College English Curriculum Requirements (2004), and the influence of CET-4 on College English teaching is not very great; that, in test preparation classes, the skills trained, activities conducted and materials used are solely consistent with those required in CET-4 and the normal teaching is broken; that the nature of the impact of CET-4 on a variety of aspects of College English teaching and learning is both positive and negative, but there are more positive than negative effects; that CET-4 can, to some degree, promote the teaching and learning of College English; and that, according to the implementation of College English Curriculum Requirements (2004) and CET reform, there is an obvious increase in the time spent on listening, speaking, reading and writing in classes, especially listening and speaking.展开更多
According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on...According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on the surface of a curved electrode is derived,which takes account of the effects of local stress and the radius of mean curvature. From this relationship, the overpotential is found to be proportional to hydrostatic stress and the activation volume under the condition of open circuit. The conditions for the deposition of the material made solely from solute atoms and the formation of surface pits and porous structures are obtained,using the generalized Butler-Volmer relationship.展开更多
文摘A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOOH,M=Fe,Co,Ni)as a model system,we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction(OER).Among the photoanodes with the three different electrocatalysts,the best OER activity,with a low-onset potential of∼1.01 VRHE,a high photocurrent density of 24.10 mA cm^(-2)at 1.23 VRHE,and a remarkable saturation photocurrent density of 38.82 mA cm^(-2),was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight(100 mW cm^(-2))in 1 M KOH electrolyte.The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport,provides a larger number of surface active sites,and results in higher OER activity,compared to other electrocatalysts.This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.
基金The work has been sponsored by the Project of Anhui University Top-quality Courses -College English( No.JIAOMIGAO[2004] 70) .
文摘This paper is a report of an empirical study of the 'washback' effects of CET-4 on College English teaching and learning in three ordinary teachers' colleges. The results of the study show that, in the first three and half terms, college English teachers can basically develop students' competence in listening, speaking, reading and writing under the guidance of College English Curriculum Requirements (2004), and the influence of CET-4 on College English teaching is not very great; that, in test preparation classes, the skills trained, activities conducted and materials used are solely consistent with those required in CET-4 and the normal teaching is broken; that the nature of the impact of CET-4 on a variety of aspects of College English teaching and learning is both positive and negative, but there are more positive than negative effects; that CET-4 can, to some degree, promote the teaching and learning of College English; and that, according to the implementation of College English Curriculum Requirements (2004) and CET reform, there is an obvious increase in the time spent on listening, speaking, reading and writing in classes, especially listening and speaking.
文摘According to the principle of thermal activation process, the energy state of a material under the action of stress is a function of local stress. A generalized Butler-Volmer relationship for the electrode reaction on the surface of a curved electrode is derived,which takes account of the effects of local stress and the radius of mean curvature. From this relationship, the overpotential is found to be proportional to hydrostatic stress and the activation volume under the condition of open circuit. The conditions for the deposition of the material made solely from solute atoms and the formation of surface pits and porous structures are obtained,using the generalized Butler-Volmer relationship.
