In Situ Synthesis of Mo2C Nanoparticles on Graphene Nanosheets for Enhanced Photocatalytic H2-Production Activity of TiO2

Molybdenum carbide (Mo 2 C) has been proven to be the most promising candidate for the H 2 -evolution cocatalyst due to the similar H + -adsorption ability to Pt. However, owing to its limited electrical conductivity, the Mo 2 C-modified photocatalysts usually exhibit a low H 2 -evolution performance. Considering the perfect electron mobility of graphene nanosheets, in this article, Mo 2 C nanoparticles (ca. 5 nm) were in-situ and evenly grown on the reduced graphene oxide (rGO) to prepare the graphene-modified Mo 2 C (rGO-Mo 2 C) nanoparticles to improve the photocatalytic hydrogen-generation rate of TiO 2 . Herein, the rGO-Mo 2 C is obtained by the direct calcination of graphene oxide (GO) as the carbon source and (NH 4 ) 6 Mo 7 O 24 at 800 °C, which is further coupled with the TiO 2 to synthesize the efficient TiO 2 /rGO-Mo 2 C photocatalyst. The greatest hydrogen-generation activity of TiO 2 /rGO-Mo 2 C achieved 880 μmol h –1 g –1 (AQE = 2.64%), which was 5.5 and 88 times higher than that of TiO 2 /rGO and TiO 2, respectively. The boosted performance of TiO 2 /rGO-Mo 2 C can be attributed to the synergetic action that the rGO nanosheets can act as electron media to promote the photoelectron transfer, and the Mo 2 C nanoparticles can serve as active centers to improve the interfacial hydrogen-generation reaction. This work can provide a new synthesis strategy for the design of efficient cocatalysts for potential applications.