Efficient optimization of nickel-cerium interface by constructing ethylene glycol ligand environment for fast water oxidation reaction kinetics

As a half-reaction to obtain high-efficiency and stable water-splitting, oxygen evolution reaction (OER) is a slow-kinetics process involving a four-electron (4e-) transfer process and therefore requires catalysts to fasten electron transfer. Here, we rationally optimized an interface material of ceria nanoparticles and nickel hydroxide by adsorbing ethylene glycol (EG-Ni(OH)2@CeO2), which produced ultrasmall nanosheets uniformly attached onto carbon cloth substrate. According to the characterization and density functional theory (DFT), the ethylene glycol-induced nickel-cerium interface had strong electron interaction, generating numerous of Ni(3-δ)+ active sites, reducing the energy reaction barrier, and promoting the electron-transport kinetics in the catalytic system. EG-Ni(OH)2@CeO2 showed excellent OER performance, with a low overpotential (335 mV) at 50 mA cm-2 and a small Tafel slope (67.4 mV dec-1). And the EG-Ni(OH)2@CeO2 also maintained stable for up to 60 h at 10, 20, and 30 mA cm-2. Overall, this research shows the significance of the interface engineering of metal materials based on organic-solvent adsorption to improve the electrocatalytic OER process.