对再生式光电化学电极的开路电位及其稳定性的探讨

ON THE OPEN CIRCUIT POTENTIAL AND STABILITYOF REGENERATIVE PHOTOELECTRO-CHEMICAL ELECTRODES

光电化学电极的开路电位及其稳定性与电解质溶液的性质有关。光电极的开路电位与照射在电极上光的强度呈半对数关系。实验表明:对n-型半导体电极,随着溶液中氧化态浓度的增加光电位向正方向移动,而改变溶液中还原态的浓度对光电位影响不大。本文根据电极过程的基本原理解释了这些事实。在某些电解质溶液中还观察到光电极光生电位的滞后现象,文中用费米能级分裂的概念对出现这一现象的原因进行了讨论。

Both the open circuit potential and stability of an illuminated photo-electrochemical electrode depend on the composition of electrolytic solution in which the electrode is immersed. The open circuit potential varies linearly with the logarithm of light intensity. The potentials of n-type semiconductor photoelectrodes shift to more positive values as the concentrations of oxidants in solutions increase, but they are almost unaffected by the concentrations of the reductants. Formula of photopotential was derived to explain these phenomena. Hysterisis of photopotential was observed in certain solutions. This phenomenon is explained by the split of Fermi-levels within surface layers of illuminated photoelectrodes.