Enhanced HO utilization efficiency in Fenton-like system for degradation of emerging contaminants: Oxygen vacancy-mediated activation of O.

Hydrogen peroxide (HO) is the most commonly used oxidant in advanced oxidation processes for emerging organic contaminant degradation. However, the activation of HO to generate reactive oxygen species is always accompanied by O generation resulting in HO waste. Here, we prepare a Ti doped MnO/FeO ternary catalyst (Ti-MnO/FeO) to create abundant oxygen vacancies (OVs), which yields electron delocalization impacts on enhancing the electrical conductivity, accelerating the activation of O to produce HO. In Ti-MnO/FeO/HO system, OVs-mediated O/O/HO redox cycles trigger the activation of locally generated O, boost the regeneration of O and on site produce HO for replenishment. This leads to a 100% removal of tiamulin in 30 min at an unprecedented HO utilization efficiency of 96.0%, which is 24 folds higher than that with FeO/HO. Importantly, further integration of Ti-MnO/FeO catalysts into membrane filtration achieved high rejections of tiamulin (> 83.9%) from real surface water during a continuous 12-h operation, demonstrating broad pH adaptability, excellent catalytic stability and leaching resistance. This work demonstrates a feasible strategy for developing OVs-rich catalysts for improving HO utilization efficiency via activation of locally generated oxygen during the Haber-Weiss reaction.