Cu2o/Wo3 S-Scheme Heterojunctions for Photocatalytic Degradation of Levofloxacin Based on Coordination Activation

Abstract

A set of Cu2O nanocluster/WO3  nanosheets S-scheme heterojunctions (CNS) containing different Cu2O contents were constructed for photocatalytic degradation of levofloxacin (LVX). The typical CNS-5 composite (5 wt% Cu2O nanocluster/WO3 nanosheets) achieves optimal LVX degradation efficiency of 97.9% within 80 min, which is much higher than WO3 (27.1%). The CNS heterojunctions confirmed by XPS and UPS results can facilitate the separation of photogenerated carriers and modulate their electronic structure. FTIR results find that the C-N of piperazine ring and C=O of carboxylic acid in LVX are coordinated with W5+ sites to build the electronic bridge between the photocatalyst and LVX, greatly promoting the further degradation. This work proposes a possible degradation mechanism coupling selective coordination activation with S-type heterojunctions and offer a new view to understand the degradation of antibiotics at molecular level.

Keywords: Keywords: Cu2O/WO3 S-scheme heterojunction, interfacial interaction, levofloxacin photodegradation, coordination activation