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

Piezo-catalytic self-Fenton (PSF) system has been emerging as a promising technique for wastewater treatment, while the competing O-2 reductive hydrogen peroxide (H2O2) production and Fe-III reduction seriously limited the reaction kinetics. Here, we develop a two-electron water oxidative H2O2 production (WOR-H2O2) coupled with Fe-III reduction over a Fe-III/BiOIO3 piezo-catalyst for highly efficient PSF. It is found that the presence of Fe-III can simultaneously initiate the WOR-H2O2 and reduction of Fe-III to Fe-II, thereby enabling a rapid reaction kinetics towards subsequent Fenton reaction of H2O2/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.

Automated summary

By using Fe-III/BiOIO3 piezo-catalyst, this study develops a highly efficient PSF system that combines two-electron water oxidative H2O2 production with Fe-III reduction. Fe-III can initiate both the water oxidative reaction and the reduction to Fe-II, thereby enabling a rapid Fenton reaction of H2O2/Fe-II. The Fe-III initiating PSF system shows exceptional self-recyclable degradation of pollutants.