Boosting electrocatalytic activity of Ru for hydrogen evolution through engineering Ru on multiple interfaces of 1T-MoS2 and carbon

Abstract

Ru is considered as highly efficient Pt-free catalyst in hydrogen evolution reaction (HER) due to its fast water dissociation kinetics. However, its strong affinity to OH* and H* greatly limits its HER performance. Herein, Ru nanoparticles (NPs) anchored on the mixed substrates of MoS2 (different 1T contents) and carbon fiber paper (Ru@MoS2-1T%/CFP) is designed and synthesized with three kinds of interfaces (MoS2/CFP, Ru/CFP, and Ru/MoS2) as excellent electrocatalyst for HER. Particularly, the Ru2@MoS2-85%/CFP presents superb HER performance with overpotential of 19 mV at 10 mA cm−2, a low Tafel slope of 29 mV dec–1 and stability of up to 10 days, outperforming reported Ru-based catalysts and Pt/C. The experimental and DFT studies disclose that the hydroxyl migration-assisted dissociation of water and interface-engineering desorption of H2 process, occurring at the mutually hybridized interface sites of Ru/MoS2/CFP, simultaneously speed Volmer/Tafel processes. Compared to Ru, the stronger interaction of 1T-MoS2 to OH* makes OH* migrate from Ru to MoS2, alleviating the poisoning of Ru sites. Also, only Ru NPs close to the interface of 1T-MoS2/CFP can achieve an optimal hydrogen adsorption energy for high HER performance. This designed strategy provides a novel idea for preparing supported Ru catalysts for excellent HER performance.