Recent Advancements in Halide and Oxide Double Perovskites as Heterogeneous Photocatalysts for Solar-Driven Photocatalytic Water Splitting and CO2 Reduction

Abstract

With many intriguing advantages, including cost-effective and outstanding optoelectronic properties such as high carrier mobility, low exciton binding energy, suitable band structure, and long carrier lifetime, all-inorganic lead-based halide perovskites (LHPs) have elicited great interest in optoelectronic fields, particularly in the photocatalysis field. However, the high toxicity and notorious instability of LHPs upon exposure to moisture, light, oxygen, and heat are significant barriers to their practical applications, prompting the development of stable lead-free perovskites. Among the various strategies, the chemical transmutations of two divalent Pb[Formula: see text] ions into one monovalent and one trivalent to form metal halide double perovskites (MHDPs) and their analogous metal oxide double perovskites (MODPs) have emerged as promising alternatives to replace the LHPs owing to their intrinsic chemical stability, eco-friendliness, comparable optoelectronic properties to the LHPs, and high catalytic activity. In this review, we elaborately discuss the recent advancements in MHDP and MODP semiconductor photocatalysts by briefly introducing their underlying fundamentals, such as history, chemical configurations, crystalline structures, electronic structures, and optical properties. Subsequently, we emphasize their contemporary applications in photocatalytic water splitting and CO2 reduction. Finally, we outline some perspectives and challenges in developing MHDPs and MODPs. We anticipated that this review might shed light on designing stable and efficient MHDP and MODP semiconductor photocatalysts for a wide range of solar applications.