Ruthenium nanoparticles loaded on N/P co-doped carbon sphere derived from sphere cross-linked hydrogel for highly improved hydrogen evolution reaction

Abstract

Developing efficient and stable catalysts for hydrogen evolution reaction (HER) in electrolysis water is crucially significant but challenging. With enhanced hydrogen bonding energy as well as a reasonable price, ruthenium-based catalysts are one of the promising catalytic materials to replace Pt for HER. In this work, nitrogen and phosphorus co-doped carbon materials supporting ruthenium nanoparticles (Ru/NPC) are prepared by two pyrolysis processes and then used as a HER efficient catalyst. In alkaline media, Ru/NPC-2 requires only a low overpotential of 64 mV to achieve the current density of 10 mA cm−2, and shows a small Tafel slope of about 76 mV dec-1 and long-lasting stability. The introduction of Ru effectively increases the electrochemical active area of the catalytic material as well as promotes sufficient contact between the surface of the catalyst and the electrolyte, thereby exposing more active sites. In addition, the normalized results show that the synergistic effect among phosphorus, nitrogen, and ruthenium effectively enhances the intrinsic activity of active sites. Therefore, Ru/NPC exhibits outstanding HER catalytic performance. This work fully demonstrates the advantages of non-metallic element-doped carbon supports in enhancing the activity of ruthenium, and has an important reference for the subsequent development of carbon-supported high-efficiency electrocatalysts.