Fabrication of highly dispersed bimetallic Ni-Mo@CNFs by sol–gel assisted electrospinning for methanol oxidation electrocatalysis

Abstract

The development of efficient electrocatalysts using low-cost nanostructured transition metals as an alternative to noble metals is receiving strong interest in the field of clean and sustainable energy technology. In this study, highly dispersed bimetallic nickel-molybdenum nanoparticles on electrospun carbon nanofibers (Ni-Mo/CNFs) were prepared using a sol-gel-assisted electrospinning technique followed by calcination. The chemical composition of the Ni-Mo/CNFs with different ratios of Mo and their morphology have been characterized by various techniques. The SEM and TEM images revealed that the Ni0.6Mo0.4/CNFs had a nanofibrous morphology, the Ni-Mo nanoparticles were highly dispersed over carbon nanofibers, and the average particle size was 9.02 nm. The Mo ratio plays a crucial role in enhancing the electrochemical performance, and Ni0.6Mo0.4/CNFs showed higher electrocatalytic activity than other samples. The maximum current density of Ni0.6Mo0.4/CNFs was 10 and 43.89 mA/cm2 for the methanol oxidation at 0.45 and 0.75 V vs. Ag/AgCl, respectively, and the onset potential was 0.31 V. The synergistic effect between Ni and Mo NPs and the morphology and structure of substrate (CNFs) were responsible for its electrochemical performance.