Cascading H2O2 photosynthesis and Fenton reaction for self-sufficient photo-Fenton reactions: A review of recent advances

Fenton reaction has gained tremendous attention in the field of non-selective pollutant degradation, as ^•OH with powerful oxidizing capacity can be produced via H₂O₂ activation. However, the widespread application is limited by the continuous consumption of commercial H₂O₂ with high price. As an alternative strategy, self-sufficient photo-Fenton reaction (SSPFR) has been explored, where oxidant H₂O₂ was in-situ produced inside the system for subsequent Fenton reactions, rather than external addition. Benefiting from the low cost, high H₂O₂ utilization efficiency, and low risk in H₂O₂ storage and transportation, SSPFR became a hotpot in scientific research, and developed rapidly in recent years. Herein, we critically reviewed the state-of-the-art development of SSPFR, in which the fundamental mechanism and catalytic process were firstly introduced. Then, SSPFR reaction was divided into three cascade steps: in-situ H₂O₂ production, H₂O₂ activation, and reactive oxygen species utilization. This paper reviewed the research progress in every step, and proposes corresponding potential strategies to accelerate the reaction rate. Finally, conclusions and prospects of SSPFR for the removal of organic pollutants were proposed. This study provides a valuable resource for researchers to construct novel and efficient SSPFR systems.