MoC quantum dots modified by CeO2 dispersed in ultra-thin carbon films for efficient photocatalytic hydrogen evolution

Abstract

MoC quantum dots are dispersed in a carbon film by the temperature-programmed method. The hybrid catalyst is obtained by the mixed solution method, and the hybrid catalyst is optimized by adjusting the content of CeO2 to obtain the composite catalyst 15%-COMCC with the best photocatalytic hydrogen evolution activity. SEM and TEM show that there is an intimate interface contact between CeO2 and MoC-QDs/C, which provides the basis for smooth electron transfer. It is proved by XPS that there is a strong interaction force between the catalysts, which provides a evidence for electron transfer between semiconductors. It is proved by electrochemistry that the introduction of CeO2 can effectively reduce the hydrogen evolution potential and provide powerful conditions for the hydrogen production of the hybrid catalyst. The carbon film has excellent conductivity, can effectively suppresses the recombination of photo-generated carriers, and accelerate the separation of carriers between the interfaces. MoC quantum dots with high dispersibility embedded in the carbon film provide a lot of active sites for photocatalytic hydrogen production. This research provides an effective strategy for the application of ultra-thin carbon film in photocatalytic hydrogen evolution, the loading of quantum dots, and the design and synthesis of non-noble metals.