Ti 3 C 2 MXene cocatalyst supported Ti 3 C 2 /SrTiO 3 /g-C 3 N 4 heterojunctions with efficient electron transfer for photocatalytic H 2 production

Previous studies on photocatalytic technology have shown that doping co-catalysts and constructing composite heterojunctions are effective strategies for improving the photocatalyst performance. The Ti 3 C 2 /SrTiO 3 /g-C 3 N 4 composite photocatalyst with a gradient heterostructure was prepared by the high-temperature calcination method with Ti 3 C 2 as the co-catalyst. The effects of g-C 3 N 4 content on the microstructure and hydrogen evolution rate of the Ti 3 C 2 /SrTiO 3 /g-C 3 N 4 composites were investigated under simulated sunlight. The results showed that the photocatalyst with 60 wt% of g-C 3 N 4 had the optimal hydrogen evolution rate of 1733.13 μmol g −1 h −1 after simulated sunlight irradiation for 4 h, which was approximately 3.3 times higher than that of Ti 3 C 2 /SrTiO 3 . After four photocatalytic hydrogen evolution cycles, no significant decrease in the hydrogen evolution rate of the Ti 3 C 2 /SrTiO 3 /g-C 3 N 4 composite was observed. This work may serve as a rational reference on the synergistic effect of heterostructures and cocatalysts to improve the separation effect of electron–hole pairs, thus improving the hydrogen evolution effect of the catalyst.