Preparation of novel p-n heterojunction Bi2O2CO3/BiOBr photocatalysts with enhanced visible light photocatalytic activity

In this study, a novel Bi2O2CO3/BiOBr p-n heterojunction was synthesized, via a two-step solvothermal method. The p-n interface was formed by loading Bi2O2CO3 nanoparticles on the surface of BiOBr nanosheets. The crystal structure, morphology, and optical property of the as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-vis diffuse reflectance spectroscopy, respectively. The obtained Bi2O2CO3/BiOBr p-n heterojunction composites exhibited the superior photocatalytic activity for the degrading rhodamine B (RhB) under visible light irradiation as compared with Bi2O2CO3 and BiOBr. Four times cycling experiments demonstrated that the composites had good photostability and recyclability. The enhanced photocatalytic activity of Bi2O2CO3/BiOBr composites was mainly attributed to the formation of p-n heterojunction between Bi2O2CO3 and BiOBr, thereby resulting in faster transfer of the photoinduced electron-hole pairs through their interface. Radical trapping experiments confirmed that h(+) and O-center dot(2)- were two main active species in the photocatalytic process. The possible mechanism of the enhanced photocatalytic activity was proposed, which revealed the transfer of the charge carriers and the formation of the active species in photocatalytic process. (C) 2017 Elsevier B.V. All rights reserved.