Highly Efficient FeIII‐initiated Self‐cycled Fenton System in Piezo‐catalytic Process for Organic Pollutants Degradation

Abstract Piezo‐catalytic self‐Fenton (PSF) system has been emerging as a promising technique for wastewater treatment, while the competing O 2 reductive hydrogen peroxide (H 2 O 2 ) production and Fe III reduction seriously limited the reaction kinetics. Here, we develop a two‐electron water oxidative H 2 O 2 production (WOR−H 2 O 2 ) coupled with Fe III reduction over a Fe III /BiOIO 3 piezo‐catalyst for highly efficient PSF. It is found that the presence of Fe III can simultaneously initiate the WOR−H 2 O 2 and reduction of Fe III to Fe II , thereby enabling a rapid reaction kinetics towards subsequent Fenton reaction of H 2 O 2 /Fe II . The Fe III initiating PSF system offers exceptional self‐recyclable degradation of pollutants with a degradation rate constant for sulfamethoxazole (SMZ) over 3.5 times as that of the classic Fe II ‐PSF system. This study offers a new perspective for constructing efficient PSF systems and shatters the preconceived notion of Fe III in the Fenton reaction.