Lattice strain-mediated MoSe₂ enable superior piezocatalysis activity for upcycling of organic pollutants

Piezocatalytic upcycling of organic pollutants in wastewater into value-added chemicals rather than CO₂ is a dual solution to the environmental and energy crisis, but due to the rapid recombination of piezoelectric electron-hole pairs and the significant reaction barriers for intermediate adsorption and dissociation, which result in a sluggish reaction kinetics. Here, we present a MoSe₂ piezocatalyst with lattice strain that collaboratively regulates d-band center and the orbitals hybridization between metal sites and *CO₂ as well as *COOH intermediates to achieve rapid conversion of carbon intermediate to critical *COOH intermediates, accelerating the overall carbon reduction with a lower reaction energy barrier. Mechanism study reveals that lattice strain can regulate the local electronic structures of Mo sites, not only improve the adsorption and activation of carbon intermediate, but also inhibit the H* formation from the H₂O dissociation, thereby shifting the carbon reduction mechanism from H*-mediated reduction to proton-coupled electron transfer. Simultaneously, peroxymonosulfate acts as an important bridge to promote oxidation reaction and then provide a sufficient carbon source for CO formation. The lattice strained MoSe₂ exhibits CO production performance of 155.60 μmol·g^-1 and phenol degradation of 100%, 20 mg·L^-1. This work deepens the comprehension of how lattice strain influences carbon reduction, and simultaneously offers a feasible approach for recycling real wastewater through fuel production and synchronous advanced treatment.