Green Hydrogen Production from Ethanol Electrolysis Using Co/Ni Bimetallic Nanoparticles-Incorporated Carbon Nanofibers

Abstract

This manuscript presents a novel approach for green hydrogen production through ethanol electrolysis using Co/Ni bimetallic nanoparticles-incorporated carbon nanofibers (CNFs). The synthesis method involves the electrospinning of a sol-gel comprising nickel acetate, cobalt acetate, and poly(vinyl alcohol), followed by vacuum drying at 60°C overnight and subsequent calcination in a vacuum atmosphere. X-ray diffraction (XRD) analysis revealed the decomposition of acetate precursors, resulting in the formation of zero-valent metal nanoparticles (NPs). Transmission electron microscopy (TEM) confirmed the alloy composition of the NPs. Electrochemical measurements demonstrated the effective utilization of the proposed nanofibers as anode materials in ethanol electrooxidation reactions for hydrogen production at low voltage. Optimization of the metallic nanoparticle composition was found to significantly enhance performance. For instance, Ni- and Ni_0.9Co_0.1-doped CNFs exhibited current densities of 37 and 142 mA/cm², respectively. Especially, Ni_0.1Co_0.9-doped CNFs displayed a remarkably low onset potential of -50 mV vs. Ag/AgCl. Moreover, Ni_0.9Co_0.1-doped CNFs exhibited the ability to recover hydrogen from ethanol solutions from 0.1 to 5 M, attributed to the observed active layer regeneration. The versatility of ethanol as a feedstock, derived from biomass fermentation, positions the proposed anode materials as sustainable catalysts for green hydrogen production from agricultural sources. This work underscores the potential of Co/Ni bimetallic nanoparticles-incorporated CNFs in advancing the field of renewable energy and promoting sustainable H₂ generation.