Adsorbed Oxygen-Induced d-p Orbital Hybridization for Piezocatalytic H2O2 Production, Antibiotic Degradation and Detoxification.

Developing efficient water purification technologies without external chemical inputs is critical for treating emerging contaminants. Herein, we report a Cu2WS4-CoPc composite piezocatalyst that enables efficient in situ H2O2 production and pollutant degradation via enhanced oxygen activation. The introduction of CoPc induces interfacial electron transfer from Cu2WS4 to CoPc and promotes O2 activation through d-p orbital hybridization between Co and O2, as confirmed by density functional theory calculations showing a decrease in O2 adsorption energy from +1.2 to -0.3 eV. Consequently, the composite exhibits significantly enhanced piezoelectric response, with increased piezoelectric constant and effective longitudinal piezoelectric coefficient. The optimized Cu2WS4-CoPc generates H2O2 via a two-electron oxygen reduction pathway, with superoxide radicals (·O2 -) as the key intermediate, achieving a yield of 183.4 µM within 30 min, which far exceeds that of pristine Cu2WS4. Moreover, the catalyst degrades ciprofloxacin with a rate constant of 0.059 min-1, approximately 4.5 times higher than pure Cu2WS4, and zebrafish toxicity assays confirm effective detoxification of degradation intermediates. This study provides a new strategy for enhancing piezocatalytic H2O2 synthesis through strengthened oxygen activation and lays a theoretical foundation for designing efficient, environmentally benign water treatment technologies.