Electrodeposition of amorphous molybdenum sulfide thin film for electrochemical hydrogen evolution reaction

Amorphous molybdenum sulfide (MoS(x)) is a highly active noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER). The MoS(x) was prepared by electrochemical deposition at room temperature. Low-cost precursors of Mo and S were adopted to synthesize thiomolybdates solution as the electrolyte. It replaces the expensive (NH)(2)MoS(4) and avoid the poison gas (H(2)S) to generate or employ. The (MoO(2)S(2))(2−), (MoOS(3))(2−) and (MoS(4))(2−) ions were determined by UV–VIS spectroscopy. The electrodeposition of MoS(x) was confirmed with XRD, XPS and SEM. The electrocatalyst activity was measured by polarization curve. The electrolyte contained (MoO(2)S(2))(2−) ion and (MoOS(3))(2−) ion electrodeposit the MoS(x) thin film displays a relatively high activity for HER with low overpotential of 211 mV at a current density of 10 mA cm(−2), a relatively high current density of 21.03 mA cm(−2) at η = 250 mV, a small Tafel slope of 55 mV dec(−1). The added sodium dodecyl sulfate (SDS) can efficient improve the stability of the MoS(x) film catalyst. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13065-019-0600-0) contains supplementary material, which is available to authorized users.