Enhanced Photocatalytic Removal of Hexavalent Chromium over Bi12 TiO20/RGO Polyhedral Microstructure Photocatalysts

Abstract

A Bi12 TiO20/RGO photocatalyst with polyhedron microstructure was fabricated via the template-free hydrothermal method, and the visible-light-induced photocatalytic activity of the prepared Bi12 TiO20 was also evaluated by the photocatalytic reduction of heavy metal pollutants. The structures and optical properties of the prepared Bi12 TiO20/RGO were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–vis diffuse reflectance spectrum (UV–vis DRS). The effects of the reaction time and mineralizer concentration on the formation of the Bi12 TiO20 polyhedral microstructure were analyzed. The enhanced photocatalytic performances of Bi12 TiO20/RGO were observed which were ascribed to the combination of the Bi12 TiO20 microstruc-ture induced photogenerated charges and the RGO nanostructure as a photogenerated charges carrier. The effect of organic acids, p-hydroxybenzoic acid (PHBA), chloroacetic acid, and citric acid on the Cr(VI) photocatalytic reduction was also discussed. This work provides an insight into the design of the bismuth-based microstructure photocatalyst towards the application for environment purification of heavy metals.