Developing Dipole-scheme Heterojunction Photocatalysts

TL;DR

This paper introduces a novel dipole-scheme heterojunction model for photocatalysts that enhances charge separation and redox reactions, leading to improved photocatalytic efficiency, demonstrated through first-principles calculations on PtSeTe/LiGaS2.

Contribution

The paper develops a new D-scheme heterojunction model and demonstrates its potential for high-efficiency photocatalysis using first-principles calculations.

Findings

Effective electron-hole separation via polarization field.

Enhanced photocatalytic redox reactions with large driving voltages.

High potential for hydrogen and oxygen evolution reactions.

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. The D-scheme heterojunction not only can effectively separate electrons and holes by a large polarization field, but also boosts photocatalytic redox reactions with large driving photovoltages and without any carrier loss. By means of first-principles and GW calculations, we propose a D-scheme heterojunction prototype with two real polar materials, PtSeTe/LiGaS2. This D-scheme photocatalyst exhibits a high capability of the photogenerated carrier separation and near-infrared light absorption. Moreover, our calculations of the Gibbs free energy imply a high ability of the hydrogen and oxygen evolution reaction by a large driving force. The proposed D-scheme photocatalytic model is generalized and paves a valuable route of significantly improving the photocatalytic efficiency.