Fabrication of MXene-Bi2WO6 heterojunction by Bi2Ti2O7 hinge for extraordinary LED-light-driven photocatalytic performance

Abstract

Heterojunction composites with intimate interfaces can shorten the diffusion distance, which leads to a shorter path for photogenerated carriers, thereby increasing photocatalytic activity. Herein, we report the fabrication of Ti3C2-Bi2WO6 (TC-BW) heterojunctions hinged by Bi2Ti2O7 joints via an in situ hydrothermal reaction of Ti3C2 in the presence of Na2WO4 and Bi(NO3)(3). The TC-BW was characterized using X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), and Raman spectroscopy. TC-BW showed superior photocatalytic activity (productivity over 15TC-WB reaches up to 5.0 mmol(reacted BA)g(cat.)(-1)h(-1)) in the oxidation of benzyl alcohol using light-emitting diode (LED) light, arising from the surface defects and intimate heterojunction interface between the Ti3C2 MXene and Bi2WO6 nanosheets. TC-BW heterojunctions provide an enhanced separation efficiency of photogenerated charges, which in turn yields superior photocatalytic activity. Furthermore, it is well substantiated by density functional theory (DFT) calculations. In summary, this study elucidates the preparation of heterojunction composites with intimate interfaces for highly efficient photooxidation.