Catalytic activity for the hydrogen evolution reaction of edges in Janus monolayer MoXY (X/Y = S, Se, and Te)

Monolayer transition metal dichalcogenides (TMDs) have been regarded as the most promising low-cost alternatives to noble metals as catalysts for the hydrogen evolution reaction (HER). However, their limited catalytically active sites for the HER hinder their practical application. In this paper, the catalytic performances of the edge sites of Janus monolayer MoXY (X/Y = S, Se and Te) were investigated using density functional theory. The results show that both the Mo-edge and chalcogen atomic edges of Janus monolayer MoXY are catalytically active for the HER; thus Janus monolayer MoXY exhibits better catalytic performance than monolayer MoS2. These results are useful for the improvement of the catalytic performance of TMDs by the formation of the Janus monolayer MoXY.