Effective periodate activation by peculiar Cu2O nanocrystal for antibiotics degradation: The critical role of structure and underlying mechanism study

Exploring efficient catalyst and unveiling relevant intrinsic mechanism for pollutants control based on periodate (PI) activation is urgently required. Herein, an effective catalyst Cu2O with peculiar exposed facets and crystal edges was firstly developed to activate PI towards antibiotic wastewater degradation. Intriguingly, Cu2O nanocrystals with {100}+ {111} co-exposed facets together with their shared crystal edges exhibited the intrinsic high catalytic activity, and 88.90% of tetracycline (20 mg L-1) could be rapidly degraded within 5 min with kobs= 0.378 min-1, which outperformed the {100}, {110}, {111} solely exposed ones or {100}+ {110}, {100}+ {110}+ {111} co-exposed ones. A comprehensive mechanism study revealed that the crystal edges of {100}/{111} in Cu2O nanocrystals are conducive to better electron transfer, charge separation, and PI adsorption properties, thus triggering highly efficient PI activation over other crystal edges exposed nanocrystals. Besides, {100}/{111} crystal edges in Cu2O crystal made the PI activation-induced antibiotic degradation change from the non-radical/radical mixed reaction to 1O2 (75.71%) dominated nonradical reaction. This work provides systematical insights into constructing effective catalysts for wastewater treatment via structure engineering.