Multidimensional engineering of MoS2 electrocatalysts: Bridging edge-site activation, phase modulation, and defect control for efficient hydrogen evolution

Molybdenum disulfide (MoS 2 ) is a transition metal compound with a layered structure and unique physical and chemical properties, which has been widely explored as a catalyst for the electrocatalytic hydrogen evolution reaction (HER). The crystal structure of MoS 2 consists of an S–Mo–S layer, in which the edge sites are considered to be catalytically active. However, challenges are still faced regarding the defect control, stability, electrical conductivity, and large-scale synthesis of MoS 2 . This review summarizes the use of MoS 2 in HER and explores its advantages as a catalyst for hydrogen generation, as well as outlines challenges and strategies to improve its catalytic efficiency. Particular focus has been given to summarizing various methods for the activation of edge sites to improve the electrocatalytic performance of MoS 2 . In addition, nanostructuring of MoS 2 , doping and heterostructures, phase transition control, surface modification, and advanced synthesis technologies to improve edge site activation and overall catalytic performance have been reviewed. Further, the potential of MoS 2 in practical HER applications, future research directions, and comparison with other electrocatalytic reactions have been elaborated. Although MoS 2 is widely regarded as a competitive electrocatalyst for hydrogen production, further research work is needed to harness its potential in the electrolyzes for hydrogen energy.