HERs in an acidic medium over MoS2 nanosheets: from fundamentals to synthesis and the recent progress

Abstract

The generation of sustainable and eco-friendly energy is the lifeline of modern civilization. Electrocatalytic water splitting producing molecular hydrogen using inexpensive, non-noble metal, and eco-friendly materials is a promising and sustainable approach that can minimize the dependency on fossil fuels and the carbon footprint of society. However, there are some major obstacles such as complex/sluggish reaction pathway, high overpotential, low catalyst durability, limited faradic efficiency and pricey catalyst (Pt, Ir, and Ru) in the process of constructing commercial electrochemical HER systems, and hence, there is an immediate need for fabricating a cost-viable non-precious HER electrocatalyst. In addition to the widespread use of 2D metal chalcogenides, in particular MoS₂, this layered electrocatalyst shows robust catalytic performance towards hydrogen evolution reactions under grating acidic conditions. However, its catalytic efficiency is still inferior to that of the standard catalyst (Pt). Thus, through this Mini review, we try to cover the fundamentals, underlying catalytic mechanism, activity evaluating parameters, future opportunities, and associated challenges with MoS₂ electrocatalysts and adopted advanced strategies for subduing the shortcomings. Furthermore, different edge and basal plane modification strategies, various developed MoS₂ preparation techniques, and characteristic advantages of MoS₂ nanosheets towards HERs are also briefly discussed. Additionally, the review provides a comprehensive collection of the latest pioneering research outcomes on layered MoS₂ for HER applications, particularly in acidic electrolytes. The included state-of-the-art MoS₂ catalytic performance, synthesis procedure, and advanced modification methods will act as a guiding tool to tune other materials accordingly to achieve the benchmark activity and turn the dream of H₂-fuel commercialization in an environmentally sustainable manner, i.e. by non-noble metal-based HER electrocatalysis.