Synergistic engineering of MoS2 via dual-metal doping strategy towards hydrogen evolution reaction.

• Improve the electric conductivity of the MoS 2 by Cu dopant. • Realize the phase transition of MoS 2 from 2H phase to 1T phase by Pd dopant. • Increase active site density via synergistic effects of Cu and Pd doping. • Improve HER intrinsic activity of MoS 2 via synergistic effects. Molybdenum disulfide (MoS 2) is reckoned as one of the most positive low-cost HER catalysts to replace platinum-based precious metals in acid media. Unfortunately, some issues preclude MoS 2 from being truly applicable including limited active sites, poor conductivity and lack of intrinsic activity. Herein, we report a Cu, Pd co-doped MoS 2 nanomaterial as an efficient and stable HER electrocatalysts, which partially resolve the above-mentioned problems and leads to high overall performance. Specifically, we improve the electric conductivity of the MoS 2 by Cu dopant and realize the phase transition of MoS 2 from pristine 2H phase to stable 1T phase by Pd dopant. More importantly, we increase active site density to facilitate fast electrocatalytic Faradaic process via synergistic effects of Cu and Pd doping, and tune electronic energy states of MoS 2 to improve HER intrinsic activity. In acidic media, the performance of Cu-Pd-MoS 2 catalyst in terms of a low overpotential (−93 mV) at 10 mA cm−2, a small Tafel slope of 77 mV dec−1, and an excellent stability is better than that of single-doped catalysts. [ABSTRACT FROM AUTHOR]