The insights into facet-dependent catalytic performance of Cu2O in peroxymonosulfate activation for effective degradation of antibiotics

It was of great significance to improve the performance of catalysts in peroxymonosulfate (PMS) activation for water pollution control. Herein, Cu2O-based catalysts with different exposed facets were synthesized by a feasible method, and later employed for activating PMS to conduct the degradation tests of tetracycline (TC). With the increase of exposed (1 0 0) facet, the specific surface area of Cu2O was improved and the interface charge transfer resistance was reduced. More interestingly, benefiting from the exposure of (1 0 0) facet, the electron-donating ability of Cu2O was boosted, and the adsorption energy of PMS over Cu2O was also reduced, thereby creating favorable conditions for PMS activation. As guessed, Cu2O-1 with (1 0 0) facet can quickly activate PMS to achieve the effective degradation of TC, and the highest removal efficiency of TC over Cu2O-1 can be up to 97.56 % within 15 min. Furthermore, Cu2O-1 with good anti-interference showed satisfactory reusability, and the degradation intermediates of TC were the low toxic or nontoxic. In the Cu2O-1/PMS system, various reactive oxygen species were detected, including SO4•–, OH•, O2•– and 1O2, and wherein the contribution of 1O2 to TC degradation was the greatest. In short, current work shared some valuable insights into persulfate-based advanced oxidation processes.