Self-cycling nanozymes: Cubic Cu2O-mediated peroxidase-like degradation and detoxification of tetracycline antibiotics.

The development of high-performance nanozyme for degrading tetracycline antibiotics (TCs) offers a promising strategy. In this work, the cubic Cu2O nanozymes were synthesized via a surfactant-free hydrothermal strategy. Consequently, the Cu2O nanozymes activated H2O2 to generate hydroxyl radicals (·OH), achieving efficient broad-spectrum degradation of TCs (including oxytetracycline, chlorotetracycline, and tetracycline). Significantly, the designed degradation system achieved >95% removal efficiency for all TCs within 60 min. Specifically, Density functional theory calculations unveiled that the Cu2O (111) facet drives homolytic H2O2 cleavage with a remarkably low activation barrier (-2.3 eV) to generate ·OH, while post-reaction characterization confirmed exceptional structural stability, sustaining >50% Cu(I) content and 92% ·OH activity over four cycles. Remarkably, the degradation system demonstrated efficient broad-spectrum removal (85.4-98.2%) in real water with concomitant detoxification through hydroxylation and ring-cleavage pathways. In conclusion, this work presents a practical nanozyme strategy for simultaneous antibiotic degradation and detoxification, to prevent secondary contamination.