MoS₂-Based Electrocatalysts Across Major Water-Related Energy Reactions: Advances, Challenges, and Future Prospects

Water electrochemical reactions have garnered increasing attention due to their central role in sustainable energy conversion. Amid the intensifying global energy crisis, the development of renewable pathways for green hydrogen production has become imperative. Numerous materials have been investigated as electrocatalysts for water splitting and fuel cell technologies, with molybdenum disulphide (MoS₂) emerging as a particularly promising candidate owing to its versatility in major aqueous electrochemical processes. This review provides an integrated perspective on recent advances in MoS₂ as a multifunctional electrocatalyst for hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction and hydrogen oxidation reaction, the key half-reactions that govern water splitting and fuel cell systems. The kinetics of these reactions, governed by the Sabatier principle, can be optimised through careful control of proton-coupled electron transfer pathways. MoS₂ has attracted significant attention not only as a non-noble catalyst but also as a robust support for constructing highly active catalytic systems. Its layered framework, tuneable electronic structure and inherent defect sites provide a versatile platform that can be engineered into efficient catalytic systems, enhancing reaction kinetics, intermediate binding and overall activity. This review examines and compares the activity of MoS₂-based catalysts and summarises recent progress and challenges in their development as electrocatalysts for water-related energy applications.