Enhanced Photocatalytic Removal of Hexavalent Chromium over BiTiO/RGO Polyhedral Microstructure Photocatalysts.

A BiTiO/RGO photocatalyst with polyhedron microstructure was fabricated via the template-free hydrothermal method, and the visible-light-induced photocatalytic activity of the prepared BiTiO was also evaluated by the photocatalytic reduction of heavy metal pollutants. The structures and optical properties of the prepared BiTiO/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 BiTiO polyhedral microstructure were analyzed. The enhanced photocatalytic performances of BiTiO/RGO were observed which were ascribed to the combination of the BiTiO microstructure 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.