Recent advances in CoSe2 electrocatalysts for hydrogen evolution reaction

Hydrogen as a sustainable alternative fuel is recognized as a primary choice for future energy supply due to its high gravimetric energy density and zero carbon emission upon combustion. Electrochemical water splitting is a promising strategy for effective and sustainable hydrogen production. Nowadays, research is focused on developing non-precious, stable, and highly efficient electrocatalysts for hydrogen evolution reaction (HER). Among them, CoSe2 has attracted tremendous attention as HER electrocatalyst due to its unique electronic configuration that ensures fast charge transport, excellent catalytic activity, and good chemical stability. So far, a lot of reviews on electrocatalytic water splitting based on transition metal dichalcogenides and cobalt-based materials are reported. However, the review on CoSe2 electrocatalyst for hydrogen evolution reaction is limited up-to-date. Hence in the present review, a comprehensive literature survey on CoSe2 electrocatalyst for hydrogen evolution reaction is done and reported. In this review, the crystal structures of CoSe2, their phase transformation strategy, their hydrogen evolution reaction mechanism in acidic and alkaline electrolytes are highlighted. The various synthesis procedures adopted to produce CoSe2 based materials, the relation between its structure and composition with their electrocatalytic activities are discussed. Moreover, the effective ways to enhance the electrocatalytic performance of CoSe2 based materials such as its morphological modification, constructing heterostructures, and heteroatom doping are reviewed.