“…H 2 is considered as an ideal sustainable energy source to reduce the use of fossil fuels, because it only generates H 2 O after combustion and possesses high energy density . The water electrolysis technique could transfer solar or wind energy into a hydrogen source through the hydrogen evolution reaction (HER), showing great potential for large-scale generation of H 2 . − To realize such an electrocatalysis H 2 generation route, the key is to explore highly active catalysts with low-price materials. The earth-rich transition metal materials receive intensive attention because of the efficient catalysis activity, diverse compounds, and tuned electronic structure. − For instance, transition-metal-based materials of nitrides, , phosphides, − sulfides, − selenides, , hydroxides, − and carbides , have been researched extensively.…”