Synergistic effect of In2+ doping in MoS2 nanosheets for rapid hydrogen production

Abstract

The advancement of outstanding durability nanocatalysts is a major step in solving the pressing global issues of energy depletion and environmental degradation. Green hydrogen generation through the efficient water electrolysis is the strategic solution. Herein, the high yield liquid phase exfoliation approach is used to create the In_xMo_1-xS₂ (x = 0, 0.05, 0.1) nanosheets. In_xMo_1-xS₂ nanosheets have excellent phase purity with hexagonal crystal structure with (002) preferred orientation. In acidic water (0.5 M H₂SO₄), improved hydrogen evolution reaction (HER) with low overpotential of 103 mV versus RHE has been obtained by bimetal In_xMo_1-xS₂ nanosheets based electrocatalysts because of their increased electrochemical surface area and synergistic impact. Non-noble In_xMo_1-xS₂ electrodes demonstrate accelerated due to modified chemical environment around Mo-sites by In-doping. In-dopants increases the density of electrons around Mo-sites due to low its electronegativity, which leads to presence of additional empty d-orbitals and decreases the charge transfer resistance from 276 Ω for pristine MoS₂ to 20 Ω for In_0.05Mo_0.95S₂. For determining the optimal HER activity, Gibbs free energy calculations are carried out throughout the reaction route using density functional theory. The current study offers a more thorough understanding of how indium doping can supply catalytic active sites for improved HER performance. This research demonstrates the potential of energy saving hydrogen generation using In_xMo_1-xS₂ nanosheets.