The dual gain strategy of introducing nickel doping and anchoring amorphous iron oxyhydroxide nanosheets on ZIF-67 achieves an efficient oxygen evolution reaction

A ZIF-67@Ni@FeOOH composite material was synthesized using nickel-doped ZIF-67 as a precursor and was electrochemically characterized as an efficient oxygen evolution reaction (OER) catalyst. The results indicated that Ni doping preserved the polyhedral structure of ZIF-67 while enhancing its OER activity. The introduction of amorphous FeOOH nanosheets allowed ZIF-67@Ni@FeOOH to not only retain its original polyhedral structure but also develop a hollow interior and self-remodeling surface, resulting in numerous defects. These features contribute to improved charge transfer efficiency and enhanced conductivity of the material. The dual enhancement effect is achieved by combining the doping strategy with structural defect engineering. The synergistic effects of Co, Ni, and Fe species further boost OER performance. The ZIF-67@Ni@FeOOH catalyst exhibited remarkable OER efficacy, with the lowest overpotential at a current density of 10 mA cm−2 being 329 mV and a low Tafel slope of 42.95 mV dec−1. In situ Raman spectroscopy revealed that high-valence hydroxyl oxides, specifically NiOOH and CoOOH, present on the composite surface were the active species for OER. This study offers a promising approach for developing economically viable electrocatalysts with superior efficiency for OER.