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 Cu 2 WS 4 -CoPc composite piezocatalyst that enables efficient in situ H 2 O 2 production and pollutant degradation via enhanced oxygen activation. The introduction of CoPc induces interfacial electron transfer from Cu 2 WS 4 to CoPc and promotes O 2 activation through d-p orbital hybridization between Co and O 2 , as confirmed by density functional theory calculations showing a decrease in O 2 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 Cu 2 WS 4 -CoPc generates H 2 O 2 via a two-electron oxygen reduction pathway, with superoxide radicals (·O 2 − ) as the key intermediate, achieving a yield of 183.4 µM within 30 min, which far exceeds that of pristine Cu 2 WS 4 . Moreover, the catalyst degrades ciprofloxacin with a rate constant of 0.059 min −1 , approximately 4.5 times higher than pure Cu 2 WS 4 , and zebrafish toxicity assays confirm effective detoxification of degradation intermediates. This study provides a new strategy for enhancing piezocatalytic H 2 O 2 synthesis through strengthened oxygen activation and lays a theoretical foundation for designing efficient, environmentally benign water treatment technologies.