Transparent conductive oxides in photoanodes for solar water oxidation.

Rational designs of the conductive layer below photocatalytic films determine the efficiency of a photoanode for solar water oxidation. Generally, transparent conductive oxides (TCOs) are widely used as a conductive layer. In this mini review, the fundamentals of TCOs are explained and typical examples of nanoscale TCOs are presented for application in photoelectrochemical (PEC) water oxidation. In addition, hybrid structures formed by coating other photocatalysts on nanoscale TCOs are discussed. In the future, the nanostructured electrode may inspire the design of a series of optoelectronic applications.