Kinetics of light-driven oxygen evolution at α-Fe2O3 electrodes

被引：272

作者：

Peter, Laurence M. ^{[1
]}

Wijayantha, K. G. Upul ^{[2
]}

Tahir, Asif A. ^{[2
]}

机构：

[1] Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England

[2] Univ Loughborough, Dept Chem, Loughborough LE11 3TU, Leics, England

来源：

FARADAY DISCUSSIONS | 2012年 / 155卷

基金：

英国工程与自然科学研究理事会;

关键词：

INTENSITY-MODULATED PHOTOCURRENT; PHOTOELECTROCHEMICAL IMPEDANCE SPECTROSCOPY; HEMATITE ALPHA-FE2O3; SEMICONDUCTOR ELECTRODES; HYDROGEN GENERATION; FERRATE(VI) ION; PASSIVE FILM; WATER; MECHANISM; IMPS;

D O I：

10.1039/c1fd00079a

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The kinetics of light-driven oxygen evolution at polycrystalline alpha-Fe2O3 layers prepared by aerosol-assisted chemical vapour deposition has been studied using intensity modulated photocurrent spectroscopy (IMPS). Analysis of the frequency-dependent IMPS response gives information about the competition between the 4-electron oxidation of water by photogenerated holes and losses due to electron-hole recombination via surface states. The very slow kinetics of oxygen evolution indicates the presence of a kinetic bottleneck in the overall process. Surface treatment of the alpha-Fe2O3 with dilute cobalt nitrate solution leads to a remarkable improvement in the photocurrent response, but contrary to expectation, the results of this study show that this is not due to catalysis of hole transfer but is instead the consequence of almost complete suppression of surface recombination.

引用

页码：309 / 322

页数：14

共 34 条

[1] Decoupling Feature Size and Functionality in Solution-Processed, Porous Hematite Electrodes for Solar Water Splitting [J].