Construction of BiOBr/Ti3C2/exfoliated montmorillonite Schottky junction: New insights into exfoliated montmorillonite for inducing MXene oxygen functionalization and enhancing photocatalytic activity

Abstract

Currently, poor stability and excessive –F terminal groups of Ti3C2 MXene notably restrains the synthesis and potentiality exploitation of MXene-based photocatalysts. Herein we offered facile and cost-effective tactics by introducing exfoliated montmorillonite (MMTex) to efficiently inhibit oxidation of Ti3C2 during the hydrothermal synthesis process, simultaneously weakening the adverse effects of surface –F terminations and achieving surface oxygen (O) functionalization of Ti3C2. Ternary BiOBr/Ti3C2/MMTex was first fabricated via microsphere BiOBr assembled on O-functionalized MMTex/Ti3C2 using in-situ coprecipitation coupling with microwave hydrothermal method. Representative characterizations demonstrated that BiOBr/Ti3C2/MMTex possessed a stable hybrid structure, intimate interfacial coupling and superior photoelectric performance. Enhanced generation of •OH and •O2– radicals over the BiOBr/Ti3C2/MMTex photocatalysis system were confirmed in comparison to that of pristine BiOBr and BiOBr/Ti3C2, which owed to excellent separation and migration of photogenerated charges achieved by synergetic effects of Schottky barrier and Charges repulsion. Thus, BiOBr/Ti3C2/MMTex achieved superior degradation for multiple organic pollutants. Furthermore, the enhanced photocatalytic mechanisms, three plausible CIP degradation pathways, and detailed assessments of the biological toxicity of intermediates were proposed. The study provides a novelty option to exploit efficient and stable MXene-based photocatalysts by utilizing low-priced montmorillonite for environmental remediation.