RuCo alloy bimodal nanoparticles embedded in N-doped carbon: a superior pH-universal electrocatalyst outperforms benchmark Pt for the hydrogen evolution reaction

Abstract

Developing cost-effective and high-performance electrocatalysts for hydrogen evolution reaction (HER) in all pH conditions is of great significance for scalable and sustainable hydrogen production through electrochemical water splitting. Herein, a novel hybrid composed of RuCo alloy bimodal nanoparticles embedded in N-doped carbon was prepared from pillar-layered chiral metal–organic frameworks via one facile encapsulation-pyrolysis strategy. Due to the unique hybrid structure and composition, the optimized RuCo@NC-600 (prepared at a pyrolysis temperature of 600 °C) catalyst exhibits outstanding HER catalytic activities in alkaline, acidic, and neutral media. Remarkably, the RuCo@NC-600 achieves a current density of 10 mA cm⁻² at extremely low overpotentials of 34, 6 and 60 mV in 1.0 M KOH, 0.5 M H₂SO₄ and 1.0 M PBS solutions, respectively, superior to the benchmark Pt/C catalyst. In addition, a symmetric two-electrode alkaline electrolyzer device pairing RuCo@NC-600 as both cathode and anode displays excellent performance, along with an impressive stability without noticeable attenuation up to 120 h. This work paves the way to the rational development of efficient pH-universal HER electrocatalysts.