Partially amorphous NiFe-based bimetallic hydroxide nanocatalyst for efficient oxygen evolution reaction

Exploring high-efficiency earth-abundant electrocatalysts facilitates advances in sustainable energy conversion and storage. Herein, partially amorphous NiFe hydroxide nanoparticles were synthesized via a facile solvothermal method for application as a highly efficient and stable electrocatalyst to produce oxygen by water decomposition. The partially amorphous phase and tunable component ratio of the NiFe-based hydroxide nanoparticles contributed to their excellent electrocatalytic oxygen evolution reaction (OER) activity. Overpotentials of 265 and 296 mV were required to deliver current densities of 10 and 50 mA cm−2, respectively, and the Tafel slope was as low as 58.6 mV dec−1 in 1.0 M KOH. Besides, the OER performance of the nanoparticles was stable for more than 35 h. Ex situ Raman spectroscopic and electrochemical analyses revealed that the defect sites were the electrochemically formed in the metal hydroxide. The proposed approach provides a reliable method for enhancing the performance of other NiFe-based catalysts for water oxidation.