Boosted Oxygen Evolution Reaction in Bimetallic Alloy Nanoparticles/Carbon Composite via Simple One-Step Molten Salt-Assisted Synthesis

Abstract

The growing need for energy conversion technologies has stimulated the development of innovative electrocatalysts designed explicitly for oxygen evolution reactions (OER). Nonprecious metal/carbon-based composites are widely studied for this purpose due to their low cost and unique structures. However, conventional methods for preparing transition metal/carbon composites are often cumbersome and time-consuming. These methods have other disadvantages, such as poor catalyst uniformity, limited potential for surface modification, and excessive oxidation of metal particles. In this work, we employed a simple one-step molten salt (MS) method to synthesize FeNi alloy/carbon composites. The sample prepared by the MS strategy, with an optimal Fe/Ni ratio, performs a low overpotential of 279.4 mV at a current density of 10 mA cm^–2 and a small Tafel slope of 45.7 mV dec^–1. Compared with the sample prepared through traditional pyrolysis, the sample prepared by the MS method demonstrates modulated and optimized surface characteristics for both the carbon support and metallic particles. Furthermore, the synthetic process enables the uniform growth of alloy particles on the carbon substrate. These structural improvements result in abundant defects and active sites, significantly enhancing OER activity. Overall, this work highlights the role of the MS method in promoting the catalytic activity of FeNi alloy/carbon composites. This research contributes to advancing non-noble metal electrocatalysts for future catalytic applications.