Impact of lattice defects on water oxidation properties in SnNb2O6 photoanode prepared by pulsed-laser deposition method

SnNb2O6 is one of the promising photoanode materials for photoelectrochemical water splitting. We prepared the SnNb2O6 thin-film photoanode with various Sn/Nb ratios by a pulsed-laser deposition method and investigated impacts of lattice defects in the SnNb2O6 photoanode on the water oxidation property. Photoelectrochemical measurements and Raman spectroscopy analyses for the SnNb2O6 photoanodes presented that the water oxidation property can be improved by suppressing the formation of the acceptor site caused by the substitution of Sn4+ for the Nb5+ site in the crystal lattice of SnNb2O6. This study provides material’s design strategy based on defect chemistry to realize an efficient SnNb2O6 photoanode used for the photoelectrochemical cell, which can operate without an external bias.