TiO2/Ti3C2/g-C3N4 ternary heterojunction for photocatalytic hydrogen evolution.

Photocatalytic hydrogen (H2) generation derived by water has been considered as a renewable energy to solve environmental problems and global energy crises. Thus, it is necessary to explore the most effective photocatalysts by using multi-cocatalysts, due to an intimate interaction between different components. Therefore, we already synthesized the TiO2/Ti3C2/g-C3N4 (TTC) photocatalyst from g-C3N4 and Ti3C2 MXene via a calcination technique, and applied this composite for H2 evolution. By making use of titanium atom from Ti3C2 MXene, titanium dioxide (TiO2) was in-body developed, which leads to form a close heterostructure between metallic material and semiconductors. Besides, g-C3N4 amorphous with highly surface area also contributes to harvest light irradiation during photocatalytic activity. The optimized TTC-450 heterostructure showed a super H2 generation efficiency than those of pure g-C3N4 and other samples. Besides, TTC-450 sample also exhibited great recyclability after 4 runs. The proposed mechanism illustrates the efficient movement of generated electrons in TTC system, which leads to high H2 evolution efficiency. Moreover, the obtained results consistently emphasize the TiO2/Ti3C2/g-C3N4 composite would be a unique material for H2 production and broaden applications of MXene materials.