Alloyed Ru0.48Re0.52 nanocatalysts with electronic structure regulation for intensified alkaline hydrogen evolution reaction

Abstract

Converting electricity into hydrogen is vital for harnessing concentrated renewable energy. To achieve this, cost-effective electrocatalysts capable of withstanding mildly corrosive alkaline hydrogen evolution reaction (HER) conditions are necessary. Ru shows potential as a substitute for Pt-based electrocatalysts due to its comparable hydrogen bond strength. However, improvements are needed to overcome obstacles in water dissociation and hydrogen desorption during alkaline HER. In this work, Ru was alloyed with Re which is water dissociation-efficient to induce a redistribution of electron density in Ru0.48Re0.52 nanoparticles (NPs). These Ru0.48Re0.52NPs exhibited superior hydrogen desorption, outperforming Pt, highlighting their effectiveness in HER. The Re component received electrons from adjacent Ru while maintaining low energy barriers for water decomposition. Additionally, self-aggregation of Ru0.48Re0.52NPs was prevented by incorporating reduced graphene oxide (rGO) support, resulting in improved conductivity and electrochemical durability in Ru0.48Re0.52NPs@rGO. Through various analyses, the optimal synthesis and electronic structure adjustments in Ru0.48Re0.52NPs@rGO were confirmed, which exhibited remarkable HER overpotentials with values of 14 and 74 mV at current densities of 10 and 100 mA cm−2, respectively, in a 1 M KOH solution. These findings establish Ru0.48Re0.52NPs@rGO as a universal approach for designing efficient electrocatalysts for HER, surpassing both the activity and cost of commercialized Pt/C.