Boosting interfacial charge transfer and electricity generation for levofloxacin elimination in a self-driven bio-driven photoelectrocatalytic system

Abstract

Recently, molybdenum disulfide (MoS₂) has stimulated significant research interest as a promising electrode candidate in solar cells and energy conservation fields. Unfortunately, the short lower electron/hole migration lifetimes and easy agglomeration hamper its wide practical applications to some extent. Herein, interface engineering coupled with a bio-assisted photoelectrochemical (PEC) strategy is presented to construct a 0D MoS₂ quantum dot (QD)/1D TiO₂ nanotube electrode for pollutant elimination. Aimed at accelerating charge transfer over the 0D/1D composite interface, three types of coupling PEC models were developed to optimize the catalytic performance. The single chamber microbial fuel cell (SCMFC)-PEC integrated system was found to be the best alternative for levofloxacin (LEV) elimination (0.029 min⁻¹), and the sequential SCMFC-PEC further realized the whole system self-running independently. In addition, the interfacial electron migration and LEV degradation pathways were thoroughly investigated by LC/TOF/MS coupled with density functional theory (DFT) calculations to clearly elucidate the electron transfer paths, LEV-attacked sites and mineralization pathways in a joint sequential SCMFC-PEC system. As such, the constructed self-recycling system provides a new platform for bio-photo-electrochemical utilization, which could exhibit promising potential in environmental purification.