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

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.