Interface strain engineering of Ir clusters on ultrathin NiO nanosheets for electrochemical water splitting over 1800 hours

Strain engineering of two-dimensional(2D)material interfaces represents a powerful strategy for enhanc-ing the electrocatalytic activity of water splitting.However,maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge.The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets(NSs)derived from metal organic frameworks(lr@NiO/C_(BDc)),which displays a high activity and stability under all pH conditions,and even a change of only 1%in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions.Through combined experimental and computational studies,we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/CBDC catalyst,arising from its increased Ir and Ni vacancy formation energies,and hence suppressing its leach-ing.Moreover,strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by op-timizing its electronic structure and coordination environment.This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.

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 m V)at 50 m A cm^-2 and a small Tafel slope(67.4 m V dec^-1).And the EG-Ni(OH)2@CeO2 also maintained stable for up to 60 h at 10,20,and 30 m A 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.