A BiOCl film synthesis from Bi2O3 film and its UV and visible light photocatalytic activity

A facile method was proposed to prepare BiOCl film on a Ti substrate using Bi2O3 film reacting with Cl- in acidic condition. The as-prepared BiOCl film was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM) and UV-vis diffuse reflectance spectra (UV-vis DRS). The BiOCl film owned a hierarchical nanostructure and a nucleation-dissolution-recrystallization growth mechanism was observed according to the FESEM at different reaction time. The photocatalytic activity of the BiOCl film was investigated by degradation of 50 mL 5 mg L-1 Rhodamine B (RB) solution under UV and visible light, strong adsorption capacity (more than 10% RB adsorbed on the surface before light on) and excellent photocatalytic performance were observed. 100% and more than 90% color removal efficiencies were achieved under UV and visible light in 120 min and 180 min, better than that obtained by TiO2 film, especially under visible light. Meanwhile more than 90% and 70% TOC could also be removed under UV and visible light in the same condition. The analysis of RB photocatalytic degradation mechanisms suggested that the prepared BiOCl film exhibited high activity for direct semiconductor photoexcitation RB degradation under UV light, while it also possessed superior activity for indirect RB photosensitization degradation under visible light. The prepared BiOCl film also exhibited excellent photocatalytic activity for other dye solutions and possessed the potential application in wastewater treatment. (C) 2013 Elsevier B.V. All rights reserved.