Modulation of morphology and electronic structure on MoS₂-based electrocatalysts for water splitting

Electrocatalytic water splitting into hydrogen is one of the most favorable approaches to produce renewable energy. MoS₂ has received great research attention for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) due to its unique structure and ability to be chemically modified, enabling its electrocatalytic activity to be further enhanced or made comparable to that of Pt-based materials. In this review, we discuss the important fabrication approaches of MoS₂ ultrathin nanosheet (MoS₂ NS) to improve the intrinsic catalytic activity of bulk MoS₂. Moreover, several modification strategies involve either morphology modulation or electron structural modulation to improve the charge transfer kinetics, including doping, vacancy, and heterojunction construction or single-atom anchor. Our perspectives on the key challenges and future directions of developing high-performance MoS₂-based electrocatalysts for overall water splitting are also discussed.