Synergistic redox reactions toward co-production of H₂O₂ and value-added chemicals: Dual-functional photocatalysis to achieving sustainability

Integrating H2O2 evolution with oxidative organic synthesis in a semiconductor-driven photoredox reaction is highly attractive since H2O2 and high-value chemicals can be concurrently produced using solar light as the only energy input. The dual-functional photocatalytic approach, free from sacrificial agents, enables simultaneous production of H2O2 and high-value organic chemicals. This strategy promises a green and sustainable organic synthesis with minimal greenhouse gas emissions. In this review, we first elucidate the fundamental principles of cooperative photoredox integration of H2O2 synthesis and selective organic oxidation with simultaneous utilization of photoexcited electrons and holes over semiconductor-based photocatalysts. Afterwards, a thorough review on the recent advancements of cooperative photoredox synthesis of H2O2 and value-added chemicals is presented. Notably, in-depth discussions and insights into the techniques for unravelling the photoredox reaction mechanisms are elucidated. Finally, critical challenges and prospects in this thriving field are comprehensively discussed. It is envisioned that this review will serve as a pivotal guidance on the rational design of such dual-functional photocatalytic system, thereby further stimulating the development of economical and environmentally benign H2O2 and high-value chemicals production.