Recent progress on earth abundant electrocatalysts for hydrogen evolution reaction (HER) in alkaline medium to achieve efficient water splitting – A review

Developing earth-abundant-electrocatalysts for hydrogen evolution reaction is one of the promising ways to achieve efficient water-splitting for hydrogen production (a clean chemical fuel). This paper reviews the activity, stability and durability for hydrogen evolution reaction in alkaline medium of different types of recently reported potential electrocatalysts such as Ni, Co, NiCo, Fe, Cu, W, Mo, Se, Mn, Zn, V, and metal free based earth-abundant-electrocatalysts. Further, this paper reviews the strategies used to achieve the remarkably low overpotential (including η10: ≤ 35 mV), high long term stability (including ≥ 100 h) and high durability (including ≥ 5000 cycles) of potential earth-abundant-electrocatalysts for hydrogen evolution reaction in alkaline medium and those are better or well comparable with the state-of-the-art, noble, Pt/C electrocatalyst. Finally, this paper summarizes the efficient strategies such as preparing porous structured materials, preparing nanostructured materials with superaerophobic surface, preparing nanostructured materials, preparing carbon composites/integrating electrocatalysts with carbon, preparing amorphous materials, preparing materials with oxygen vacancies/defects, preparing metal chalcogenides, preparing bimetallic/multi-metallic materials, doping metals or heteroatoms, preparing electrocatalysts with core-shell structure, decorating electrocatalysts with amines, preparing homo-junction/heterojunction structured materials, preparing hollow structured materials, and preparing boron-rich surface to enhance the activity, stability, and durability for HER.