Photocatalytic H2 Evolution on TiO2 Assembled with Ti3C2 MXene and Metallic 1T-WS2 as Co-catalysts

The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3 C2 MXene and metallic octahedral（IT） phase tungsten disulfide（WS2） act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3 C2 MXenes and 1 T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3 C2 composite.Thus,a distinctive 1 T-WS2@TiO2@Ti3 C2 composite with double metallic co-catalysts was achieved,and the content of IT phase reaches 73%.The photocatalytic H2 evolution performance of 1 T-WS2@TiO2@Ti3 C2 composite with an optimized 15 wt% WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3 C2 MXene and 1 T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1 T-WS2 on the surface of TiO2@Ti3 C2 composite enhances the Brunauer-Emmett-Teller surface area and boosts the density of active site.