Abstract
Environmental pollution from persistent pharmaceuticals like carbamazepine (CBZ) poses severe risks to aquatic ecosystems and human health, yet conventional treatments struggle with low concentrations and secondary pollution. Piezo-photocatalysis, which harnesses mechanical and solar energies to drive charge separation, offers a promising alternative using materials such as molybdenum disulfide (MoS(2)), whose layered structure enables tunable piezoelectricity but is hindered by rapid electron-hole recombination and structural instability. However, the mechanistic role of oxygen doping in repairing sulfur vacancies and enhancing symmetry-breaking for improved performance remains underexplored. Here we show that hydrothermally synthesized oxygen-doped MoS(2) (O(5)-MoS(2)) fully degrades 2 mg L(-1) CBZ in 25 min under combined ultrasound and visible light, achieving a rate constant (k (obs)) of 0.13 min(-1)-11.4 times higher than undoped MoS(2). This stems from oxygen substitution narrowing the bandgap to 1.94 eV, boosting the piezoelectric coefficient to 63 p.m. V(-1) (versus 26 p.m. V(-1)), and generating a 0.19 V built-in potential that drives charge separation, as confirmed by 4.18 μA cm(-2) synergistic photocurrents, density functional theory calculations revealing heightened Mo-O charge transfer (2.08-2.36 e(-)), and finite element simulations of deformation-induced fields. Over five cycles, O(5)-MoS(2) retains 100 % efficiency with minimal Mo leaching (1.9 %), reducing product toxicity across fish, daphnid, and algal models. These findings delineate oxygen doping's dual role in defect mitigation and polarization enhancement, paving the way for robust piezo-photocatalytic systems in real-world water purification.