Solar-driven co-evolution of H₂ and H₂O₂ from pure water splitting over emerging photocatalysts: Detailed mechanism and future outlook

Abstract

Hydrogen (H₂) energy is projected as a rising star to support the future society, and hydrogen peroxide (H₂O₂) is widely utilized as a raw material in medical and chemical fields. Photocatalytic water splitting might enable an entire and sustainable environment for natural H₂ evolution and concurrent H₂O₂ production, thus receiving increasing attention and realizing continuous achievements in recent years. However, such a reaction still suffers from the lacking of welldesigned photocatalytic systems with abundant active sites, and the efficiency is still far away from the standard of industrial-scale application. Benefiting from constant experimental and theoretical investigations, this choke point has been considered by constructing diverse photocatalysts with modulated electronic, chemical, and physical properties. In this sense, this review critically outlines the state-of-the-art progress on water splitting for H₂ and H₂O₂ production over discovered photocatalytic systems, including titanium dioxide, carbon nitride, metal sulfides, etc. The general principles, including the thermodynamics and kinetics analysis, emerging issues, and corresponding strategies, are discussed. Significantly, some lessons drawn from the previous literature concerning simultaneous H₂ and H₂O₂ production are proposed, and the main challenges in the future developments are summarized and clearly considered. This review aims to give a deep understanding of the photocatalytic water splitting for H₂ and H₂O₂ co-evolution and show some solutions to the future challenges in this field.

Keywords

H₂ evolution / H₂O₂ generation / photocatalysts / water splitting

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2023 2023 The Authors. PhotoMat published by University of Shanghai for Science and Technology and Wiley-VCH GmbH.