Efficient Hydrogen Evolution Catalyst Constructed by Pt-Modified Ni3S2/MoS2 with Optimized Kinetics Across the Full pH Range

Abstract

Electrocatalyst materials play a crucial role in determining the efficiency of the hydrogen evolution reaction (HER), directly influencing the overall effectiveness of energy conversion technologies. Ni3S2/MoS2 heterostructures hold substantial promise as bifunctional catalysts, owing to their synergistic electronic characteristics and plentiful active sites. However, their catalytic efficacy is impeded by the relatively elevated chemisorption energy of hydrogen-containing intermediates, which constrains their functionality in different pH environments. In order to mitigate this limitation, trace amounts of Pt are introduced into the heterostructure, intending to enhance electronic transport and refining chemisorption energies, thereby facilitating significant enhancements in both hydrogen evolution reaction and oxygen evolution reaction activities over a wide pH range. It is revealed that the Pt-modified catalyst achieves exceptional HER performance, requiring merely 64 mV and 83 mV overpotentials to attain a current density of 100 mA cm⁻² in acidic and alkaline media, respectively. Furthermore, theoretical simulations corroborate that Pt modification optimizes local electronic configurations and augments electronic transfer, contributing to its superior catalytic performance. This investigation underscores the pivotal role of Pt modification in propelling the practical application of Ni3S2/MoS2 heterostructures as highly efficient and pH-universal bifunctional catalysts.