Strong interaction heterointerface of NiFe oxyhydroxide/cerium oxide for efficient and stable water oxidation

NiFe oxyhydroxides (NiFeO x H y ) are the benchmark catalysts for alkaline oxygen evolution reaction (OER), however, it is still challenging for these electrocatalysts to achieve both high activity and long-term stability. Herein, we demonstrate that strong interaction heterointerface of NiFeO x H y /cerium oxide (CeO 2 ) can control the reconstruction process of NiFeO x H y and the reaction pathway of OER, which simultaneously improves the activity and stability of the catalyst. Interestingly, after electrochemical activation, with and without CeO 2 , NiFeO x H y oxyhydroxides exhibit completely different structures, with the former being uniformly distributed ultrafine nanosheets and the latter being spherical agglomerates of larger sized nanosheets. The strong heterointerface interaction induces the electrons of Ni and Fe to shift to Ce. The optimized catalyst exhibits a low overpotential of 240 mV at 100 mA cm −2 with the durability over 2000 h at 200 mA cm −2 . The OER mechanism studies indicate that NiFeO x H y /CeO 2 heterointerface follows lattice oxygen oxidation mechanism with accelerated kinetics.