Immortally Dual Sites on Single-Atom Dispersed Electrocatalyst for High-Efficient Hydrogen/Oxygen Evolution Reaction

Abstract

Real bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) should be the ones that exhibit an immortal behavior during catalysis without structural transformation or surface reconstruction. Otherwise, they could be only termed as “pre-catalysts” rather than the real catalysts. Herein, single-atom dispersed catalysts (SACs) embedding atomically dispersed Ru onto nickel-vanadium layered double hydroxide matrix (termed as Ru/Ni3V-LDH) not only exhibit excellent HER activity (~ 54.3 fold mass activity vs. the commercial Pt/C) and OER activity, but also possess decent full-cell performance for overall water splitting (1.5 V@10 mA cm-2). Most importantly, in-situ XAS and Raman spectroscopic studies clarified that, unlike numerous bifunctional catalysts that have suffered from the structural reconstruction/transformation for adapting the HER/OER cycles, Ru/Ni3V-LDH is characteristic of immortally dual reactive sites  (i.e., Ru and Ni sites) for individual catalysis of electrochemical water splitting and could be termed as the real bifunctional electrocatalyst.