Structural and Electronic Optimization of MoS₂ Edges for Hydrogen Evolution

The activity and accessibility of MoS₂ edge sites are critical to deliver high hydrogen evolution reaction (HER) efficiency. Here, a porous carbon network confining ultrasmall N-doped MoS₂ nanocrystals (N-MoS₂/CN) is fabricated by a self-templating strategy, which realizes synergistically structural and electronic modulations of MoS₂ edges. Experiments and density functional theory calculations demonstrate that the N dopants could activate MoS₂ edges for HER, while the porous carbon network could deliver high accessibility of the active sites from N-MoS₂ nanocrystals. Consequently, N-MoS₂/CN possesses superior HER activity with an overpotential of 114 mV at 10 mA cm^-2 and excellent stability over 10 h, delivering one of best MoS₂-based HER electrocatalysts. Moreover, this study opens a new venue for optimizing materials with enhanced accessible catalytic sites for energy-related applications.