Discovery of efficient visible-light driven oxygen evolution photocatalysts: Automated high-throughput computational screening of MA2Z4

Abstract

Photocatalytic oxygen evolution reaction (OER) by 2D semiconductors is a promising strategy for efficient energy conversion. The newly discovered 2D semiconductors MA(2)Z(4) (M = transition metal, e.g., Mo, W; A = C, Si, and Ge; Z = N, P, and As) have shown characteristics of promising photocatalytic OER catalysts. Herein, an automated high-throughput workflow is proposed to efficiently screen MA(2)Z(4) photocatalytic OER catalysts, and further reveal the theoretical mechanism. The four criteria of semi-conductivity, bandgap width/band edge position, structural stability, and free energy change, are proposed to screen MA(2)Z(4) catalysts thermodynamically. The exciton properties and carrier mobility of these MA(2)Z(4) are further studied to explore the high-efficiency photocatalytic OER MA(2)Z(4) with low exciton binding energy and high effective mass ratio. It is found that the bandgap width of MA(2)Z(4) mainly depends on the strength of M-Z bonding and the redistribution of electrons, while the catalytic effect is closely related to the adsorption capacity of O atom. In particular, beta-ZrSi2N4 and beta-HfSi2N4 are screened as efficient photocatalytic OER catalysts. This work develops a fully automated method and contributes to a complete framework for screening high-efficiency photocatalytic OER catalysts.