Modulation of reaction pathway of Prussian blue analogues derived Zn-Fe double oxides towards organic pollutants oxidation

The radical-based Fenton-like reaction quenching by various inorganic anions or high concentration of organic matters restrict the practical value in future industrial application. Contrarily, the nonradical-dominated system could efficiently overcome above limitations and achieve excellent catalytic capacity under a wide category of water matrixes. Herein, a series of Zn-Fe double oxides were successfully fabricated via calcination of Zn1-xFex-Fe Prussian blue analogues under ambient atmosphere. Under the coexistence of visible light and peroxymonosulfate (PMS), Zn-Fe double oxides manifested excellent catalytic performance towards various organic pollutants oxidation with trace amount of iron leaching, and even showed superior contaminant decomposition efficiency under high concentration of organic matter and practical aqueous system. Confirmed by radical trapping experiment and electron paramagnetic resonance spectroscopy, the photo-induced electrons and holes can act as triggers to PMS activation and thereby transform reaction routes from radicals to singlet oxygen (1O2)-dominated nonradical pathway over the prepared Zn-Fe double oxides. This work provided new insights and comprehension into modulating radical and nonradical pathways of PMS-based advanced oxidation process for refractory contaminant oxidation via utilizing solar energy.