Novel BiOCl/TiO2 hierarchical composites: Synthesis, characterization and application on photocatalysis

In this paper, a novel BiOCl/TiO2 hierarchical composite was successfully synthesized by a facile one-pot solvothermal synthesis with the aid of polyvinylpyrrolidone (PVP). Then, the as-prepared composite was characterized by field-emitting scanning electron microscope (FESEM), transmission electron microscopy (TEM), N-2 adsorption/desorption, X-ray power diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and electrochemical impedance spectroscopy (EIS), respectively. Research shows that this novel composite exhibits superior visible-light response, enhanced photo activity and photostability for the formation of the BiOCl/TiO2 heterojunctions. Especially, the rate constant of the photocatalyst with the molar ratio of anatase TiO2 about 30% for decomposing RhB, can reach about 0.1510 min(-1), is far superior to commercial P25, as-prepared anatase TiO2 nanopartides and tetragonal BiOCl alone. In addition, the superoxide radicals (center dot O2-) and photogenerated holes (h(+)) were demonstrated to be the main active radicals in this photodegradation process. This study further reveals that the enhanced photoactivity of this photocatalyst should be ascribed to the successful formation of BiOCl/TiO2 heterojunctions and the rapid migration of the interface charges. (C) 2016 Elsevier B.V. All rights reserved.