Surface modify BiOBr/Mn-Ti3C2Tx to enhance the carrier separation efficiency and weak electron utilization for photo-assisted peroxymonosulfate activation to degrade emerging contaminants

Abstract

The low separation efficiency and light utilization of photogenerated carriers are one of the key problems in photocatalysis. This, Mn-Ti3C2Tx was prepared by surface modification of Ti3C2Tx, BiOBr/Mn-Ti3C2Tx composite photocatalysts were synthesized through in situ ion modification. The synergy of surface modification and built-in electric field improves carrier separation efficiency and weak electron utilization. This can promote electrocatalytic reduction of peroxymonosulfate (PMS) to produce SO4·- and improve electron utilization. The various photovoltaic properties characterization found that BiOBr/Mn-Ti3C2Tx exhibited superior light capture ability and carrier separation efficiency compared to BiOBr/Ti3C2Tx, and thus had more efficient photocatalytic degradation performance, which was found to be increased from 90.88% to 98.29% using emerging contaminants as the target pollutant. Secondly, the migration path of carriers in BiOBr/Mn-Ti3C2Tx was analyzed by In Situ Irradiated X-Ray Photoelectron Spectroscopy (ISI-XPS) as well as the proposed mechanism of ciprofloxacin (CIP) degradation by BiOBr/Mn-Ti3C2Tx photo-assisted activation of PMS. The possible pathways of CIP degradation were further explored by liquid chromatograph mass spectrometer (LC-MS), revealing that the BiOBr/Mn-Ti3C2Tx photocatalytic degradation pathways. In this work, a strategy of surface modification and built-in electric field synergy is proposed to improve the photogenerated carrier separation and light utilization efficiency for enhancing the emerging contaminants removal.