MXene-derived C-doped TiO2/Ti3C2 heterojunction as a high-performance visible-light photocatalyst

Fabrication TiO2 with conductive two-dimensional materials is an effective strategy to improve its photocatalytic activity. Herein, a well-defined carbon-doped TiO2/Ti3C2 heterojunction is constructed via in situ controllable oxidation of Ti3C2 MXene in carbon dioxide. The formed C-doped TiO2 nanoparticles as the photocatalyst uniformly disperse on the surface of Ti3C2 MXene and generate electrons and holes under irradiation. The two-dimensional Ti3C2 MXene, owing to its excellent conductivity, acts as the electron transport channels and accelerates the separation of photogenerated electrons and holes. Meanwhile, due to its large specific surface area and good solubility, Ti3C2 MXene may facilitate to enhance the adsorption of pollutant on the photocatalyst as well as the absorption of photocatalyst for visible light. Therefore, the unique merits of TiO2 and Ti3C2 MXene are integrated to deliver the composites high photocatalytic activity. The proper content of Ti3C2 MXene and TiO2 in the composite is crucial for enhancing the photocatalytic performance, which can be effectively tuned by varying the oxidation temperature. In this work, C-doped TiO2/Ti3C2 oxidized at 400 °C presents the optimum photocatalytic performance.