Oxynitride, Oxyfluoride, and Nitrofluoride Perovskites: Theoretical Evaluation of Photon Absorption Properties for Solar Water Splitting

Abstract

Photocatalytic water splitting represents a very promising but at the same time challenging contribution to a clean and renewable route to produce hydrogen fuel. Developing efficient and cost-effective photocatalysts for water splitting is a growing need. For this purpose, semiconductor photocatalysts have attracted much more attention due to their stability and low manufacturing cost. Here, we have systematically applied several state-of-the-art advanced first-principles-based methodologies, viz., hybrid density functional theory, many-body perturbation theory (G 0 W 0 ), and density functional perturbation theory (DFPT), to understand the electronic structure properties of ABX 2 Y perovskites. We have chosen the vast composition space of ABX 2 Y type perovskites where A and B are cations, and X and Y can be nitrogen, oxygen, or fluorine. These perovskites exhibit direct band gaps ranging from 1.6 to 3.3 eV. In addition, to evaluate the feasibility of the visible light catalytic performance, we have calculated the structural, electronic, and optical properties of ABX 2 Y perovskites. Furthermore, from the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) mechanism, BaInO 2 F, InSnO 2 N, CsPbO 2 F, and LaNbN 2 O are found as probable photocatalysts.