Ce‐Modified Ni(OH)2 Nanoflowers Supported on NiSe2 Octahedra Nanoparticles as High‐Efficient Oxygen Evolution Electrocatalyst

Abstract Exploring and developing high‐efficiency electrocatalysts for the oxygen evolution reaction (OER) is desirable yet challenging for cost‐effective transformation of renewable electricity into fuels and chemicals. Herein, a self‐supported electrode of nanoflower‐like Ce‐modified Ni(OH) 2 grown on high‐conductivity NiSe 2 octahedra nanoparticles is designed and fabricated for the first time. By virtue of i) the high conductivity of the NiSe 2 support for favorable electron transfer; ii) the open porous structure from the nanoflower‐like Ce‐modified Ni(OH) 2 for beneficial mass transport; iii) Ce doping for efficiently optimizing the energetics for OER intermediates based on density functional theory simulations; and iv) Ce(OH) 3 embedding for efficacious oxygen ion exchange and electronic transmission, the electrode exhibits remarkable OER activity with a very low overpotential of 158 mV at 10 mA cm −2 and Tafel slope of 27 mV dec −1 , which outperform almost all OER electrocatalysts.