Extending MoS2-based materials into the catalysis of non-acidic hydrogen evolution: challenges, progress, and perspectives

Water splitting is regarded as among the most prospective methods of generating green hydrogen. Switching electrolytes of water electrolysis from acidic to non-acidic ones will enable the use of noble-metal-free electrocatalysts and mitigate material corrosion, thus lowering the capital cost of water electrolyzers and improving their operational stability. However, increasing electrolyte pH will degrade the hydrogen evolution reaction (HER) activity because of the reduced concentration of H _3 O ^+ as reactants, making non-acidic HER sluggish. To accelerate HER, MoS _2 -based materials with the advantages of unique atomistic structure, low cost, and high abundance have been considered prospective electrocatalysts to substitute for Pt in acid. Great efforts are being spent on extending MoS _2 -based materials into the catalysis of non-acidic HER, and their further development requires clarification of the existing challenges and current progress. However, it has not yet been discussed for non-acidic HER on MoS _2 -based electrocatalysts. To mitigate the disparity, we systematically overview MoS _2 -based electrocatalysts for non-acidic HER, covering catalytic mechanisms, modulation strategies, materials development, current challenges, research progress, and perspectives. This review will contribute to the rational design of MoS _2 -based materials for high-performance HER in non-acidic conditions.