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[Display omitted] The development of efficient catalysts for hydrogen evolution reaction (HER) from water splitting is one of the most promising strategies to achieve the goal of peak carbon dioxide emissions and carbon neutrality. Herein, Ru nanoclusters decorated MoSe 2 nanosheets supported on a Crepis tectorum fluff biomass-derived hollow carbon tube (Ru-MoSe 2 /CMT) are prepared as the HER catalysts in both alkaline and acidic conditions. The Ru modification induces the transformation of MoSe 2 from 2H phase to 1T phase. Benefiting from the strong water dissociation ability of Ru, Ru-MoSe 2 /CMT exhibits a low overpotential of 70 mV with a Tafel slope of 39 mV dec-1 in 1 M KOH. Furthermore, the assembled Ru-MoSe 2 /CMT || RuO 2 system with a low cell voltage of 1.54 V at 10 mA cm−2 exhibits outstanding overall water splitting performance superior to Pt/C || RuO 2 system. The Ru-MoSe 2 /CMT || RuO 2 system also achieves the excellent stability of up to 30 h in 1 M KOH. The synergy effect between Ru and MoSe 2 , as well as the improved electron transfer kinetics provided by the biomass-derived carbon substrate together contribute to the excellent HER activity of Ru-MoSe 2 /CMT. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoSe 2 -MoSe 2 (1–1)/rGO has good HER activity in both acidic and alkaline media. • The CoSe 2 -MoSe 2 (1–1) nanosheets uniformly decorate the rGO matrix. • DFT results verify CoSe 2 -MoSe 2 (1–1) heterostructure owns small band gap and ΔG H*. • The rGO matrix and heterojunction structure improve the electronic conductivity. It is important to develop novel energy to solve energy shortage and environmental problems. Hydrogen evolution reaction (HER) is envisaged as a viable technology that can be used to develop sustainable clean energy. Herein, we report a catalyst with CoSe 2 -MoSe 2 heterostructure grown on reduced graphene oxide with an optimum Co/Mo proportion of 1:1 (CoSe 2 -MoSe 2 (1–1)/rGO). It exhibits good HER activities in both acidic and alkaline conditions. The CoSe 2 -MoSe 2 (1–1)/rGO shows an overpotential of 107 mV at 10 mA cm−2 with a Tafel slope of 56 mV dec−1 under acidic condition. Meanwhile, CoSe 2 -MoSe 2 (1–1)/rGO also presents an overpotential of 182 mV at 10 mA cm−2 and with a Tafel slope of 89 mV dec−1 under alkaline condition. These impressive performances of the catalyst are mainly due to the excellent electronic transmission capability of rGO and the abundant active sites of CoSe 2 -MoSe 2 heterostructure as well as the optimized hydrogen adsorption energy of CoSe 2 -MoSe 2 interface. The design of CoSe 2 -MoSe 2 (1–1)/rGO provides a meaningful guide for manufacturing electrode in energy storage and conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeSe 2 -MoSe 2 (1-1)/rGO has good HER activity in both acidic and alkaline media. • FeSe 2 -MoSe 2 (1-1)/rGO has well stability in both acidic and alkaline media. • On the morphology, FeSe 2 -MoSe 2 nanoparticles uniformly decorate the rGO matrix. • DFT results verify the FeSe 2 -MoSe 2 (1-1)/rGO owns small work function. It is of great significance to develop inexpensive and high-efficiency electrocatalysts for the hydrogen evolution reaction (HER). In this work, we synthesized iron molybdenum selenide (FeSe 2 -MoSe 2) loaded on reduced graphene oxide (FeSe 2 -MoSe 2 /rGO) by a one-step hydrothermal method. We further optimized the Fe/Mo ratio and determined the best ratio to be 1-1. In acidic (or alkaline) solution, the optimized FeSe 2 -MoSe 2 (1-1)/rGO has a small Tafel slope of 55 (or 80) mV dec−1 and needs an overpotential of 101 (or 178) mV to achieve 10 mA cm−2. These good properties are mainly due to the structure of bimetallic selenides combining rGO. Moreover, rGO enhances the electrical conductivity. Furthermore, the synergistic effect between FeSe 2 -MoSe 2 (1-1) and rGO results in better HER performance. Density functional theory (DFT) calculation proves that FeSe 2 -MoSe 2 (1-1)/rGO has a small work function. Based on our reasonable design and analysis, FeSe 2 -MoSe 2 (1-1)/rGO is expected to be an efficient and robust catalyst for large-scale applications. [ABSTRACT FROM AUTHOR]