BiOBr/Ti3C2 nanocomposites prepared via an octanol solvothermal method to achieve enhanced visible photocatalytic properties

Abstract

BiOBr nanospheres grown in situ on lamellar Ti₃C₂ were synthesised in an octanol solvothermal system to obtain BiOBr/Ti₃C₂ heterojunction composites with high visible photocatalytic activity (OBT). The composition, crystal structure and morphology of OBT were characterised using X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The photoelectrochemical properties of OBT were tested via UV-vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy and transient photocurrents. Results showed that the BiOBr prepared with octanol demonstrates loose nanospheres with a diameter of approximately 2 μm and clear characteristic peak intensity of the (110) crystal plane. Compared with pure-phase BiOBr and BiOBr/Ti₃C₂ heterojunction synthesis with an ethylene glycol solvothermal method (EBT), the increased visible-light response threshold of the OBT band gap and the significantly enhanced photogenerated current density of OBT effectively improve the oxidation efficiency of the aromatic ring structure. The rhodamine B degradation rate of OBT is approximately 10% higher than that of EBT. Trapping agent experiments confirmed the dominant role of ˙O₂⁻ in OBT photocatalytic processes. The results of this study can provide a basis for the analysis of the photocatalytic mechanism of OBT.