Hetero-phase MoC-Mo2C nanoparticles for enhanced photocatalytic H2-production activity of TiO2

Hexagonal molybdenum carbide (Mo2C) as an effective non-noble cocatalyst is intensively researched in the photocatalytic H-2-evolution field owing to its Pt-like H+-adsorption ability and good conductivity. However, hexagonal Mo2C-modified photocatalysts possess a limited H-2-evolution rate because of the weak H-desorption ability. To further improve the activity, cubic MoC was introduced into Mo2C to form the carbon-modified MoC-Mo2C nanoparticles (MoC-Mo2C@C) by a calcination method. The resultant MoC-Mo2C@C (ca. 5 nm) was eventually coupled with TiO2 to acquire high-efficiency TiO2/MoC-Mo2C@C by electrostatic self-assembly. The highest H2-generation rate of TiO2/MoC-Mo2C@C reached of 918 mu mol.h(-1).g(-1), which was 91.8, 2.7, and 1.5 times than that of the TiO2, TiO2/MoC@C, and TiO2/Mo2C@C, respectively. The enhanced rate of TiO2 attributes to the carbon layer as cocatalyst to transmit electrons and the hetero-phase MoC-Mo2C as H-2-generation active sites to boost H-2-evolution reaction. This research offers a novel insight to design photocatalytic materials for energy applications.

Automated summary

This study introduces a novel approach to enhance the photocatalytic activity for hydrogen evolution by introducing MoC into Mo2C to form carbon-modified nanoparticles, which are eventually coupled with TiO2 through electrostatic self-assembly. The results show that the carbon layer and hetero-phase MoC-Mo2C structure significantly improve the H2 generation rate, leading to a high-efficiency TiO2/MoC-Mo2C@C photocatalyst.