Rational Construction of a WS₂/CoS₂ Heterostructure Electrocatalyst for Efficient Hydrogen Evolution at All pH Values

The exploitation of economic, highly active, and perdurable electrocatalysts for the hydrogen evolution reaction (HER) over the entire pH range is required for production of hydrogen energy. Hence, we demonstrate unique self-supported heterogeneous WS₂/CoS₂ nanosheet arrays on carbon cloth substrates (WS₂/CoS₂/CC) derived from cobalt-based metal-organic frameworks as efficient pH-universal electrocatalysts using a facile fabrication process. Owing to the special heterostructure that can accelerate the charge transfer, the WS₂/CoS₂/CC exhibits impressive HER activities with long-term durability in pH-universal electrolytes. In 0.5 M H₂SO₄, 1.0 M phosphate buffer solution, and 1.0 M KOH, it only requires overpotentials of 146, 175, and 122 mV, respectively, to achieve a current density of 10 mA cm^-2. The rational construction of such a heterostructure provides a promising way to obtain pH-universal electrocatalysts for energy storage and conversion.