Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
Phys Chem Chem Phys. 2013 Jun 14;15(22):8772-8. doi: 10.1039/c3cp50318f. Epub 2013 Apr 30.
There is intense interest in developing new novel nanostructured photoanodes for water splitting. It is therefore important that methods to analyze the effect of nanostructuring on water splitting yields are developed in order to rationalize the relative merits of this approach for different materials. In this study the dependence of charge separation efficiency (η(sep)) on potential during photoelectrochemical water splitting at pH 2 has been quantified in a model electrode system (nanocrystalline, mesoporous TiO2) using two independent methods. These are (i) analysis of incident photon conversion efficiency (IPCE) measurements and (ii) transient absorption (TA) spectroscopy measurements. The techniques provide good agreement with each other and show that a low maximum value of η(sep) (~0.18) is the primary cause of the low IPCE for water oxidation on these nc-TiO2 electrodes.
人们对于开发新型的用于水分解的纳米结构光阳极有着浓厚的兴趣。因此，开发出分析纳米结构化对水分解产率影响的方法非常重要，以便为不同材料的这种方法的相对优点提供合理化的解释。在这项研究中，通过两种独立的方法（i）分析光电流转换效率（IPCE）测量和（ii）瞬态吸收（TA）光谱测量，在模型电极系统（纳米晶、介孔 TiO2）中量化了在 pH 2 下光电化学水分解过程中电荷分离效率（η(sep)）随电势的变化。这些技术彼此之间具有很好的一致性，并且表明低最大 η(sep)值（约 0.18）是这些 nc-TiO2 电极上水氧化的低 IPCE 的主要原因。
