Amorphous P‐CoOX Promotes the Formation of Hypervalent Ni Species in NiFe LDHs by Amorphous/Crystalline Interfaces for Excellent Catalytic Performance of Oxygen Evolution Reaction

Abstract Water electrolysis has become an attractive hydrogen production method. Oxygen evolution reaction (OER) is a bottleneck of water splitting as its four‐electron transfer procedure presents sluggish reaction kinetics. Designing composite catalysts with high performance for efficient OER still remains a huge challenge. Here, the P‐doped cobalt oxide/NiFe layered double hydroxides (P‐CoO X /NiFe LDHs) composite catalysts with amorphous/crystalline interfaces are successfully prepared for OER by hydrothermal‐electrodeposition combined method. The results of electrochemical characterizations, operando Raman spectra, and DFT theoretical calculations have demonstrated the electrons in the P‐CoO X /NiFe LDHs heterointerfaces are easily transferred from Ni 2+ to Co 3+ because that the amorphous configuration of P‐CoO X can well induce Ni‐O‐Co orbital coupling. The electron transfer of Ni 2+ to the surrounding Fe 3+ and Co 3+ will lead to the unoccupied e g orbitals of Ni 3+ that can promote water dissociation and accelerate * OOH migration to improve OER catalytic performance. The optimized P‐CoO X /NiFe LDHs exhibit superior catalytic performance for OER with a very low overpotential of 265 mV at 300 mA cm −2 and excellent long‐term stability of 500 h with almost no attenuation at 100 mA cm −2 . This work will provide a new method to design high‐performance NiFe LDHs‐based catalysts for OER.