Contror of Surface Structure and Effect of Cocatalyst Aiming at Water Splitting over Photocatalyst

Abstract

Activities of photocatalytic water splitting were improved by control of surface morphologies and loading of new cocatalysts. Doping of Ca, Sr and Ba into NaTaO₃ photocatalysts led to formation of fine crystals and control of surface morphologies such as construction of nano-step structure. The photocatalytic activities for water splitting were improved by the doping. Photocatalytic overall water splitting on K₄Nb₆O₁₇, Sr₂Nb₂O₇, KTaO₃, NaTaO₃, and NaTaO₃ doped with La photocatalysts were promoted by loading of nano-sized gold particles. The nano-sized Au worked as an active site for H₂ evolution. An IrO₂ cocatalyst which was photodeposited from an aqueous solution containing nitrate ions was also effective for overall water splitting. IrO₂ functioned as an active site for O₂ evolution.