Ti3C2 MXene-derived carbon-doped TiO2 coupled with g-C3N4 as the visible-light photocatalysts for photocatalytic H2 generation

Photocatalytic hydrogen production is a fascinating clean energy technology to solve the environmental issues and energy crisis. Herein, Ti3C2, a member of MXene, is successfully designed as a precursor for preparing C-TiO2/g-C3N4 photocatalyst without extra carbon addition, and the C-TiO2/g-C3N4 photocatalysts exhibit drastically improved photocatalytic hydrogen generation activity. When the mass ratio of Ti3C2 to g-C3N4 is 10 wt% in the composite, the prepared C-TiO2/g-C3N4 composite photocatalyst shows the highest photocatalytic H2 production activity as high as of 1409 μmol/h/g, which is about 8 times and 24 times higher than the activity of pure g-C3N4 and C-TiO2, respectively. The possible mechanism is assumed that the achieved intimate heterojunction between the Ti3C2 MXene-derived C-doped TiO2 and g-C3N4 can efficiently facilitate the photogenerated charge transfer and inhibit the recombination of electronics and holes, which markedly enhanced photocatalytic hydrogen production activity of C-TiO2/g-C3N4 photocatalysts under visible light.