Carboxylate-mediated proton transfer promotes water oxidation on spindle-like Ce-doped FeCo hydroxide

Abstract

The proton transfer plays a crucial, yet not well-control, role in enhancing the oxygen evolution reaction (OER) performance of transition metal (TM) (oxy) hydroxide materials. Herein, we take Ce-doped FeCo layered double hydroxide (Ce-FeCo LDH) nanosheets in situ growth on spindle-like MIL-88A, as a model system to demonstrate enhancing OER activity through the promotion of proton transfer by forming the carboxylate ligands coordinated with TM atoms. The carboxyl group-functionalized MIL-88A@Ce-FeCo LDH core–shell hybrid catalyst, fabricated by the one-pot reflux method, is made up of Ce-FeCo LDH as active component and carboxylate ligands as a proton acceptor. Specifically, the uncoordinated carboxylate ligands serve as relays to promote proton transfer and deprotonation efficiency. As a result, this core–shell structured hybrid exhibits superior OER activity while maintaining excellent durability. This work provides a facile method to reserve carboxylates as the station of proton transfer on TM-based catalyst to promote water splitting.