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The development and design of low-cost, high-performance catalysts with small overpotentials for hydrogen evolution in the universal-pH range still represent defiance for replacing the high-cost Pt metal catalysts and future energy technology. Herein, we designed a new electrocatalyst, N-doped carbon hollow nanospheres loaded with Ru/Mo2C Schottky junctions (denoted as Ru/Mo2C@NC), through a one-step approach by polymerization-induced self-assembly of a Mo–polydopamine hollow framework modified with ruthenium (Ru) in alkaline solution followed by in situ carbonization at high temperature. In 1 M KOH, the Ru/Mo2C@NC (Ru wt% = 3.93%) catalyst exhibits superb HER activity with a small overpotential at 10 mA cm−2 (η10 = 13 mV), a low Tafel slope of 33.24 mV dec−1, and long-term temporal stability for 72 h. Besides, the fabricated catalyst also displays low overpotentials of 21 and 41 mV to realize 10 mA cm−2 in both 0.5 M H2SO4 and 1 M PBS media, respectively, which are smaller and better than those of 20% Pt/C (26 and 59 mV). According to density functional theory (DFT) calculations, the introduction of metallic Ru into Mo2C has succeeded in constructing new active sites for H with optimal adsorption/desorption ability (ΔGH* = −0.09 eV) and maintaining relatively low water dissociation (ΔGb = 0.35 eV) in alkaline medium, endowing the composite with superb HER activity in the universal-pH range. Additionally, the outstanding catalytic HER performance is also fundamentally related to the effective influence of separating and transferring electrons from Mo2C to Ru via the Schottky junction. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) are commonly used to create complex hollow structures for energy applications. This study presents a simple method to produce a novel hollow nanoprism Co@C hierarchical composite from ZIF-67 through high-temperature treatment at 800 °C. This composite serves as a platform for Ru nanoparticle deposition, forming RuCo@C hollow nanoprism (RuCo@C HNP). As an electrocatalyst in 1 M KOH, RuCo@C HNP exhibits excellent hydrogen evolution reaction (HER) performance, with a low overpotential of 32 mV to reach 10 mA cm -2 , a Tafel slope of 39.67 mV dec -1 , a high turnover frequency (TOF) of 3.83 s -1 at η 200 , and stable performance over 50 h. It also achieves a low η 10 of 266 mV for the oxygen evolution reaction (OER) with a Tafel slope of 45.22 mV dec -1 . Density functional theory (DFT) calculations reveal that Ru doping in Ni/Co maintains a low water dissociation barrier, reduces the energy barrier for the OER rate-determining step, and creates active sites for H*, enhancing adsorption/desorption abilities. These results are attributed to the synergy between Co and Ru and the hollow prism structure's increased surface area. This method for synthesizing hollow structures using ZIF composites shows promise for applications in the energy sector., (© 2024 Wiley-VCH GmbH.)