Synthesis of MXene/COF/Cu2O heterojunction for photocatalytic bactericidal activity and mechanism evaluation

Reasonably combining the advantages of heterojunction constructed by a variety of two-dimensional materials and metal oxide nanoparticles (NPs) is an effective strategy to improve the efficiency of photocatalytic sterilization. In this work, TpPa-1-COF, as a stable semiconductor, was in situ grown on Ti3C2-MXene through the Schiff base reaction and anchored with Cu2O NPs to obtain an efficient photocatalytic bactericide. Electrochemical impedance spectroscopy and photoluminescence spectra of nanocomposites showed that the photogenerated carrier migration rate as well as the production of reactive oxygen species was improved and the carrier life was prolonged. The work function at the interface was analyzed by using the first principle calculation based on density functional theory. Both TpPa-1/Ti3C2 interface and Ti3C2/Cu2O interface had large built-in electric field to promote the migration of carriers between layers, so as to realize efficient photocatalysis and reduce photo-corrosion. The obtained Ti3C2/TpPa-1/ Cu2O nanocomposites showed excellent antibacterial rates against S. aureus and P. aeruginosa, which were antibacterial rates of 98.90% and 99.62% and were increased by 50% and 33% compared with pure TpPa-1-COF. It provides a new idea for the development of photocatalytic bactericides in the field of marine antifouling.