Recent advances in ternary transition metal dichalcogenides for electrocatalytic hydrogen evolution reaction

Green hydrogen produced from water electrolysis using excess renewable electricity is not only a clean fuel but also an important chemical feedstock vital for global decarbonization and a circular carbon economy achieved through carbon dioxide capture and conversion. Transition metal dichalcogenides have recently emerged as efficient and low-cost electrocatalysts for sustainable green hydrogen production because they exhibit hydrogen binding energies comparable to platinum group metals, outstanding electrocatalytic activities, and high electrochemical stabilities over continued operation in the acidic medium. This article focuses on the synthesis, properties, and applications of ternary transition metal dichalcogenides in hydrogen evolution reaction with emphasis on structure - composition - activity relationships. Ternary transition metal dichalcogenides can either consist of two types of transition metals and a single chalcogen element or a single transition metal with two types of chalcogen elements. This allows numerous opportunities for fine-tuning of active sites, chalcogen substitutions, heteroatom doping, particle morphologies, and phase compositions to achieve optimal electrocatalytic activity, charge transfer resistance, porosity, and hydrogen evolution reaction kinetics. Molybdenumbased ternary transition metal dichalcogenides were identified to exhibit superior catalytic activity, stability, and cost-effectiveness compared to other transition metal dichalcogenides.