Interfacial synergism in NiMoO4/FeOOH heterostructure for enhanced alkaline oxygen evolution and urea oxidation

FeOOH with excellent catalytic properties for oxygen evolution and also considered to be a true active site has attracted great interest in recent years. However, the intrinsic low conductivity limits its catalytic performance. Herein, a one‐dimensional core‐shell NiMoO4/FeOOH heterojunction with high OER activity and stability was developed. At current densities of 10 and 100 mA cm‐2, low overpotentials of 194 and 266 mV are need to drive oxygen evolution, meanwhile, the electrode exhibits high catalytic kinetics with small Tafel slopes of 53.4 mV dec‐1 and excellent stability over 100 hours. Further analysis showed that the ultrathin FeOOH layer (~5 nm) uniformly covered the surface of NiMoO4 nanorods, acting as an active species and facilitating the surface change transfer to the interior. The internal NiMoO4 cores, on the other hand, provides reliable electron transmission as a highly conductive medium, and can effectively overcome the low conductivity of FeOOH. DFT calculations further manifest the strong electronic interactions between NiMoO4 and FeOOH species. The NiMoO4 core serves as mass transport of active materials is beneficial to tune the adsorption energy of OH‐ on the surface of electrocatalysts.