In situ sulfuration synthesis of heterostructure MoS2-Mo2C@C for boosting the photocatalytic H2 production activity of TiO2

Hexagonal molybdenum carbide (Mo2C) with a similar structure to Pt as a cocatalyst has been extensively researched in the field of photocatalytic hydrogen evolution. However, owing to its limited hydrogen-evolution active sites, Mo2C-modified photocatalysts always possess a relatively poor hydrogen evolution rate. Considering that the unsaturated sulfur atoms of MoS2 easily adsorb H+ ions as hydrogen-evolution active sites, in this study, MoS2 was introduced into Mo2C@C to generate heterostructure MoS2-Mo2C@C for enhancing the photocatalytic hydrogen-production performance of TiO2. The heterostructure MoS2-Mo2C@C nanoparticles by the in situ sulfuration of Mo2C under high temperature were modified on the TiO2 surface through a simple sonication method. The experimental results showed that the maximum hydrogen-production rate of MoS2-Mo2C@C/TiO2 achieved 1160 mu mol h(-1) g(-1) (AQE = 3.48%), which was 116, 1.9, and 3.9 times higher than that of TiO2, Mo2C@C/TiO2, and MoS2@C/TiO2, respectively. The enhanced activity of MoS2-Mo2C@C/TiO2 is ascribed to the fact that the more unsaturated S atoms of MoS2-Mo2C@C, as hydrogen-generation active centers in addition to Mo sites, can efficiently adsorb H+ ions to enhance the hydrogen-production rate. This work provides a novel path for designing the heterostructure cocatalysts in the photocatalytic H-2-evolution field.

Automated summary

By introducing MoS2 into Mo2C@C, a heterostructure MoS2-Mo2C@C was formed to enhance the photocatalytic hydrogen-production performance of TiO2, which significantly increased the maximum hydrogen-production rate.