The hydrogen spillover mechanism and electronic regulation of dual sites between sub-nanometer Ru particles and Fe3C for efficient water splitting performance at industrial current density

Constructing dual active sites, adjusting electronic structures at interfaces and optimizing the adsorption energy of intermediates can effectively enhance water electrolysis performance. A novel Fe 3 C-Ru/NFs bifunctional catalyst is successfully synthesized via an electrospinning-carbonization method, in which sub-nanometer Ru particles coupled with Fe 3 C. Experimental results indicate that Fe 3 C-Ru/NFs catalyst delivers exceptional HER (18 mV@10 mA cm −2 , 202 mV@500 mA cm −2 ) and OER (263 mV@10 mA cm −2 , 382 mV@500 mA cm −2 ) performance in 1 M KOH solution. Moreover, Fe 3 C-Ru/NFs catalyst was employed as a bifunctional electrode in an overall water electrolyzer, resulting in a lower cell voltage and excellent stability (1.87 V, 150 h @ 500 mA cm −2 ). Density Functional Theory (DFT) calculation shows that the synergy between Ru and Fe sites can enhance electron transfer, and initiate a hydrogen spillover mechanism, and optimize intermediate adsorption energies, finally accelerating both HER and OER processes. This work offers valuable insights into developing low-cost, high-efficiency water electrolysis catalysts, demonstrating the significant potential for practical applications.