Doping Ba into strontium titanate for enhanced photocatalytic oxygen evolution over its supported Au-based catalysts

Developing efficient catalysts for photocatalytic oxygen evolution reaction (OER), the sluggish step of solar light driven water splitting, is significant for improving solar light utilization efficiency and accelerating the overall reaction rate. In this study, strontium barium titanate was synthesized and adopted as support of Au-based catalyst for OER. It was found that, the Au-based catalyst with a trace amount of Ba doping into strontium titanate as support (Au/Sr0.96Ba0.04TiO3) exhibited high OER catalytic activity, 4.8 times and 2.0 times higher than those obtained over Au/SrTiO3 and Au/BaTiO3, respectively. Energy level analysis indicated that Sr0.96Ba0.04TiO3 possessed suitable band positions, and the hot electrons transferred from Au to its conduction band owned moderate transfer rate and reduction potential, which ultimately resulted in high OER reaction rate. This study provides a simple way to promote the reaction rate of a catalyst in OER via doping method.