Indirect Z‐scheme TiO₂/BC/g‐C₃N₄ for efficient photocatalytic reduction of Cr(VI) in aqueous solution

Abstract

BACKGROUNDNowadays, there is an increasing concern regarding the rising issue of Cr(VI) pollution in aqueous solutions. It is crucial to find an effective technology for the removal of Cr(VI) in aqueous solutions. In this work, a novel TiO2/BC/g‐C3N4 heterostructure photocatalyst was successfully prepared by a simple hydrothermal method and characterized by SEM, TEM, XRD, BET, FT‐IR, PL, UV‐vis DRS, and XPS analysis. The photocatalytic reduction behavior of Cr(VI) on the TiO2/BC/g‐C3N4 heterostructure was investigated under visible light irradiation, and the possible mechanism of photocatalytic reduction of Cr(VI) was elucidated.RESULTSThe TiO2/BC/g‐C3N4 heterostructure photocatalyst exhibited better photo‐reduction activity for Cr(VI) under visible light irradiation. After 100 minutes irradiation with visible light, the TiO2/BC/g‐C3N4 photocatalyst achieved a removal efficiency of 89% for Cr(VI). Compared with TiO2, TiO2/BC, and TiO2/g‐C3N4, the photocatalytic removal efficiency of Cr(VI) on the TiO2/BC/g‐C3N4 increase by 40%, 20%, and 10% respectively. The photocatalytic reduction of Cr(VI) was depened on the initial concentration of Cr(VI), catalyst dosage, pH value, and atmosphere. Moreover, the TiO2/BC/g‐C3N4 presented excellent stability and reusability after five cycles.CONCLUSIONThe TiO2/BC/g‐C3N4 heterojunction enables highly efficient photocatalytic reduction of Cr(VI) under visible light irradiation. This enhancement is primarily attributed to the construction of an indirect Z‐scheme TiO2/BC/g‐C3N4 heterojunction, which significantly improves the separation efficiency of photo‐ generated charge carriers during the photochemical process. Furthermore, the presence of BC enhances the adsorption performance of Cr(VI) on the TiO2/BC/g‐C3N4, thereby facilitating its photocatalytic reduction.This article is protected by copyright. All rights reserved.