Honeycomb-like hollow carbon loaded with ruthenium nanoparticles as high-performance HER electrocatalysts

Abstract

Electrolysis of water to produce hydrogen is an effective way to prepare green hydrogen, and hydrogen evolution reaction (HER) catalysts play a very important role in the reaction. We obtained a honeycomb-like hollow carbon material through simple etching of ZIF8, which can uniformly load a low content of ruthenium nanoparticles, fully expose active sites and react with electrolytes, thereby improving its catalytic performance. ICP-OES shows that the ruthenium content is only 0.73 wt%. The HER catalytic performance of Ru/HNC is excellent, and it also has good acid-base adaptability. For Ru/HNC, in 1 M KOH, the overpotential is only 44 mV at 10 mA cm⁻², almost equivalent to that of Pt/C (31 mV). At higher current densities, its performance even exceeds that of Pt/C; the overpotential is 194 mV and 286 mV at 100 mA cm⁻² and 200 mA cm⁻², respectively. Under the same conditions, for Pt/C, the overpotential is 197 mV and 330 mV at 100 mA cm⁻² and 200 mA cm⁻², respectively. Under acidic conditions, Ru/HNC also exhibits excellent HER catalytic performance. The overpotential is 71 mV, 148 mV and 194 mV at 10 mA cm⁻², 100 mA cm⁻² and 200 mA cm⁻², respectively. In the water-splitting test, the decomposition voltage only needs 1.51 V at 10 mA cm⁻² (1.64 V, 100 mA cm⁻²).