Ultrasound-assisted two-step water-bath synthesis of g-C3N4/BiOBr composites: visible light-driven photocatalysis, sterilization, and reaction mechanism
The g-C3N4/BiOBr photocatalysts with different weight ratios were prepared by a two-step ultrasound-assisted water-bath deposition method. The materials were subsequently characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) method, Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (DRS). The photocatalytic activities of all samples were evaluated by degradation of Rhodamine B (RhB) and Escherichia coli (E. coli) under visible light driven. The results revealed that C8B2 exhibited the highest photocatalytic activity among the samples tested herein. Moreover, electrochemical tests (the Mott-Schottky curve (MS), the electrochemical impedance spectroscopy (EIS), and Tafel tests) and free radical trapping experiments were employed to analyze the flow direction of photogenerated carriers in g-C3N4/BiOBr and the mechanism of the photocatalytic reaction.