1D mesoporous NiFe2O4 nanorods fabricated by electrospinning for efficient oxygen evolution reaction

Abstract

Designing and preparing efficient and stable oxygen evolution reaction (OER) catalysts is crucial to improve water splitting performance. One-dimensional (1D) structural catalysts have received increasing attention for the OER due to their unique structural characteristics. In this study, 1D mesoporous NiFe2O4 (NFO) spinel nanorods are fabricated by electrospinning, and the differences in physical structure and electrochemical performance of NFO nanorods prepared by different electrospinning precursors are investigated. It is found that the NFO nanorods prepared by precursor of nickel-iron hydroxide particles (denoted as NFOH) exhibit a diameter of approximately 200 nm and a surface area of 26.4 m2 g−1. In 1 M KOH solution, NFOH nanorods achieve low overpotentials of respective 316 mV and 396 mV to obtain current densities of 10 mA cm−2 and 50 mA cm−2, as well as a low Tafel slope of 67.2 mV dec−1, even lower than commercial NFO. Notably, the nanorods also demonstrate excellent long-term stability. The high OER activity can be attributed to the small nanoparticle size, abundant electrochemical active sites provided by the 1D mesoporous nanostructure, and increased conductivity, which promote charge/electron transfer and enhance the conversion of active species, thereby improving the efficiency of water electrolysis. This work may broaden the perspective and approach for the structural design of OER catalysts.