Construction of Ordered Atomic Donor–Acceptor Architectures in bcc IrGa Intermetallic Compounds toward Highly Electroactive and Stable Overall Water Splitting

摘要

Benefiting from ordered atomic structures and strong d-orbital interactions,intermetallic compounds (IMCs) are promising electrocatalysts for hydrogenevolution reaction (HER) and oxygen evolution reaction (OER). Herein, thebody-centered cubic IrGa IMCs with atomic donor–acceptor architectures aresynthesized and anchored on the nitrogen-doped reduced graphene oxide(i.e., IrGa/N-rGO). Structural characterizations and theoretical calculationsreveal that the electron-rich Ir sites are atomically dispersed in IrGa/N-rGO,facilitating the electron transfer between Ir atoms and adsorbed species,which can efficiently decrease the energy barriers of the potential determiningstep for both HER and OER. Impressively, the IrGa/N-rGO‖IrGa/N-rGOexhibits excellent performance for overall water splitting in alkaline medium,requiring a low cell voltage of 1.51 V to achieve 10 mA cm~(?2), meanwhile,exhibiting no significant degradation for 100 h. This work demonstrates thatthe rational design of noble metal electrocatalysts with donor–acceptor architecturesis beneficial for catalytic reactions in energy conversion applications.