Selective hydroxyl generation for efficient pollutant degradation by electronic structure modulation at Fe sites.

Hydrogen peroxide (HO) is an important green oxidant in the field of sewage treatment, and how to improve its activation efficiency and generate free radicals with stronger oxidation performance is a key issue in current research. Herein, we synthesized a Cu-doped α-FeO catalyst (7% Cu-FeO) for activation of HO under visible light for degradation of organic pollutants. The introduction of a Cu dopant changed the d-band center of Fe closer to the Fermi level, which enhanced the adsorption and activation of the Fe site for HO, and the cleavage pathway of HO changed from heterolytic cleavage to homolytic cleavage, thereby improving the selectivity of •OH generation. In addition, Cu doping also promoted the light absorption ability of α-FeO and the separation of hole-electron pairs, which enhanced its photocatalytic activities. Benefiting from the high selectivity of •OH, 7% Cu-FeO exhibited efficient degradation activities against ciprofloxacin, the degradation rate was 3.6 times as much as that of α-FeO, and it had good degradation efficiency for a variety of organic pollutants.