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

Molybdenum carbide (Mo2C) 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 Mo2C-modified photocatalysts usually exhibit a low H-2-evolution performance. Considering the perfect electron mobility of graphene nanosheets, in this article, Mo2C nanoparticles (ca. 5 nm) were in-situ and evenly grown on the reduced graphene oxide (rGO) to prepare the graphenemodified Mo2C (rGO-Mo2C) nanoparticles to improve the photocatalytic hydrogen-generation rate of TiO2. Herein, the rGO-Mo2C is obtained by the direct calcination of graphene oxide (GO) as the carbon source and (NH4)(6)Mo7O24 at 800 degrees C, which is further coupled with the TiO2 to synthesize the efficient TiO2/rGO-Mo2C photocatalyst. The greatest hydrogen-generation activity of TiO2/rGO-Mo2C achieved 880 mu mol h(-1) g(-1)(AQE = 2.64%), which was 5.5 and 88 times higher than that of TiO2/rGO and TiO2, respectively. The boosted performance of TiO2/rGO-Mo2C can be attributed to the synergetic action that the rGO nanosheets can act as electron media to promote the photoelectron transfer, and the Mo2C 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.

Automated summary

The study introduces a new synthesis strategy for the design of efficient cocatalysts by preparing graphene-modified Mo2C nanoparticles to enhance the photocatalytic hydrogen-generation rate of TiO2. The TiO2/rGO-Mo2C photocatalyst exhibited significantly improved hydrogen-generation activity compared to TiO2/rGO and TiO2, attributed to the synergistic action of graphene nanosheets and Mo2C nanoparticles.