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

• A BiOCl/TiO2 hierarchical composite was synthesized at the presence of PVP.
• The PVP plays an important role for enhancing the photoactivity.
• This hierarchical composite exhibits enhanced photoactivity and photostability.
• This hierarchical composite exhibits rapid migration of the interface charges.
• This BiOCl/TiO2 heterojunction exhibits superior visible-light absorption ability.

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), N2 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 photoactivity 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 nanoparticles and tetragonal BiOCl alone. In addition, the superoxide radicals (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.

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