Design Principles for Construction of Charge Transport Channels in Particle-Assembled Water-Splitting Photoelectrodes

Charge transport in a photoelectrode largely influences its solar-to-chemical energy conversion efficiency. Especially, particle-assembled photoanode films are always subject to poor interparticle electron transport. The electron transport channel between the particles is usually constructed by using a necking process, in order to overcome the poor interparticle electron transport. In this study, Sb-doped SnO2, as a transparent and degenerate semiconductor, has been found to act as a novel necking material for constructing electron transport channels in particle-assembled photoanode films. As a result, it greatly improves the water-splitting performances of particle-assembled alpha-Fe2O3 photoanodes. We have formulated design principles for construction of charge transport channels in particle-assembled water-splitting photoelectrodes.