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

Abstract Hydrogen (H 2 ) energy is projected as a rising star to support the future society, and hydrogen peroxide (H 2 O 2 ) is widely utilized as a raw material in medical and chemical fields. Photocatalytic water splitting might enable an entire and sustainable environment for natural H 2 evolution and concurrent H 2 O 2 production, thus receiving increasing attention and realizing continuous achievements in recent years. However, such a reaction still suffers from the lacking of well‐designed 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 H 2 and H 2 O 2 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 H 2 and H 2 O 2 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 H 2 and H 2 O 2 co‐evolution and show some solutions to the future challenges in this field.