NiCo Nanolayered Double Hydroxides on Fe/Ni Metal–Organic Frameworks for Oxygen Evolution

Modulation of oxygen intermediates in the oxygen evolution reaction (OER) tends to be an effective method for intensifying OER activity. In this paper, NiCo nanolayered double hydroxide (NC-LDH)-decorated FeNi bimetallic metal–organic framework (FN-MIL) heterostructures were constructed for enhanced OER performance. Various characteristics including Raman and Fourier-transform infrared spectra, X-ray diffraction patterns, scanning and transmission electron microscopy images, and X-ray photoelectron spectroscopy spectra help to explore the composition and microstructure. The band gap of samples was discussed using Mott–Schottky curves and Tauc plots to analyze the interfacial electron transfer driven by the energy level difference, resulting in the formation of electron-rich and electron-deficient regions at the interface and realizing the directed modulation of oxygen intermediates. The as-prepared composite catalyst revealed excellent OER performance, long-term stability, a high faradic efficiency of 97.8%, and a low potential of 244 mV at 10 mA cm–2 (without iR-compensation). Interestingly, the catalyst maintained high OER activity in seawater containing 1 M KOH due to its favorable resistance to chloride ions, suggesting an appealing prospect in practical application.