Piezo-photocatalytic-Fenton-like ternary coupling system for enhanced resourceful conversion of organic pollutants

Greenhouse gas emissions from wastewater treatment remain a formidable challenge in reducing global carbon footprints. Here, we present a novel Co-MoS₂/ZnO (Co-ZOM)-mediated ternary coupling system integrating piezo-photocatalytic and Fenton-like processes, achieving efficient conversion of organic pollutants into carbon monoxide (CO) with minimized greenhouse gas outputs. The Co-ZOM-2 catalyst delivers an outstanding CO yield of 114.8 µmol·g^-1·h^-1, markedly surpassing the performance of previously reported systems (∼40.7 µmol·g^-1·h^-1), and achieves 16.6 % phenol conversion efficiency within 14 hours via a unique sequential oxidation-reduction pathway, where pollutants are first oxidized and then intermediate carbonates are selectively reduced to CO. The inclusion of ZnO maintains a neutral pH environment, effectively preventing potential damage to both equipment and ecosystems associated with highly acidic conditions. Notably, the ternary system demonstrates robust performance in high-salt wastewater matrices, showcasing its practical applicability. Moreover, Life Cycle Assessment (LCA) indicates that it reduces carbon emissions and lowers cumulative environmental impact compared to conventional Fenton-like methods. These findings underscore the system's potential for wastewater valorization, aligning with circular economy principles.