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Electrochemical water splitting by electricity from the renewable power sources is one of the most promising pathways for green and sustainable hydrogen production. The key is to synthesize earth-abundant and noble-metal-free electrocatalysts with outstanding hydrogen evolution reaction (HER) activity and durability in wide-pH electrolytes by simple and cost-effective methods. Herein, we reported a one-step synthesis of uniform, ultrafine molybdenum carbide (Mo 2 C) and molybdenum nitride (Mo 2 N) hybrid [together as Mo 2 (CN)] inserted carbon nanosheets as efficient electrocatalyst for HER. The as-synthesized catalyst showed an excellent HER activity in acid medium, and even superior performance was obtained in the alkaline medium. The optimal Mo 2 (CN) annealed at 750 °C showed an overpotential of −80 mV at 10 mA cm −2 and a Tafel slope of 40 mV dec −1 ; the former strikingly outperforms commercial 20% Pt/C materials (−112 mV). Moreover, Mo 2 (CN) gave an onset voltage of −33 mV and overpotential of −202 mV at 100 mA cm −2 with merely a mass loading of 0.2 mg cm −2 , which are, to date, among the best records for Mo-based catalysts in both media. The nanosheet structure providing large active area and quick charge transfer, and the synergistic effects between Mo 2 C and Mo 2 N toward HER are ascribed to the outstanding electrocatalytic activity according to the capacitive current and turnover frequency analysis. The remarkable catalytic activity and operational durability in wide pH ranges guarantee their potential for highly efficient hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • DFT calculation reveals the highly zincophilic properties of N,O dual-doping sites. • Zn deposition can be regulated by functionalized carbon nanofiber (CNF) interlayers. • The modified Zn anodes exhibit excellent plating/stripping reversibility. • Interfacial transport kinetics was studied by in-situ EIS technique. Although the intrinsic safety, low cost, and high theoretical energy densities have made the Aqueous zinc-ion batteries (AZIBs) to be a promising candidate in the application of energy storage fields. However, battery failure caused by the dendrite formation has become the major issue that disrupt their practical application. To solve that, herein, we report a unique interface strategy for regulating the interfacial electrodeposition kinetics and inhibiting dendrite formation through covering a N,O co-doped Carbon nanofiber (CNF) interlayers on Zn metal anode surface. Such CNF interlayers with robust zincophilicity can effectively capture the Zn ions, and guiding the regular Zn electrodeposition in the anode-electrolyte interface, which have been demonstrated by both theoretical calculation and experimental results. Significantly, the electrochemical tests confirmed that the cell modified with CNF interlayers exhibits a high Zn plating/stripping reversibility with a low nucleation overpotential. Notably, the modified cell enables steadily operating for 1200 h with a low overpotential of 59.5 mV at a high current density of 5 mA cm−2 (1 mAh cm−2). Moreover, the rate capability and cyclic stability of Zn-MnO 2 full battery can be greatly improved after covering the CNF interlayers on the Zn metal anode surface. This work is highly expected to provide a new route to enable dendrite-free Zn metal anodes and high-performance AZIBs. [ABSTRACT FROM AUTHOR]