Developing Dipole-scheme heterojunction photocatalysts

Abstract

The high recombination rate of photogenerated carriers is the bottleneck of photocatalysis, severely limiting the photocatalytic efficiency. Here, we develop a dipole-scheme (D-scheme for short) photocatalytic model and materials realization from first-principles dipole calculations. The D-scheme heterojunction not only can effectively separate electrons and holes by large polarization fields, but also boosts photocatalytic redox reactions with high driving photovoltages and with less carrier loss. After developing the D-scheme model, we then theoretically propose a D-scheme heterojunction prototype with two real polar materials, PtSeTe/LiGaS2. Such D-scheme photocatalyst exhibits a high capability of the photogenerated carrier separation and near-infrared light absorption. Moreover, our calculations of Gibbs free energies imply a high ability of hydrogen evolution reaction and oxygen evolution reaction by a large driving force. The proposed D-scheme photocatalytic model is generalized and paves a valuable route for significantly improving the photocatalytic efficiency.