Facile synthesis of electrospun C@NiO/Ni nanofibers as an electrocatalyst for hydrogen evolution reaction

Abstract

Hydrogen evolution reaction (HER) is considered to be one of the most important electrochemical reactions from both fundamental and application perspective to produce hydrogen. Polyacrylonitrile (PAN) based carbon (C)@NiO/Ni nanofibers were fabricated via simple electrospinning method. The as-prepared C@NiO/Ni nanofibers were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy Energy Dispersive X-ray Spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Raman spectra. The SEM and TEM analyses revealed that NiO/Ni nanoparticles distributed on the PAN based carbon nanofibers. EDS, XPS and XRD results confirm the presence of the nanoparticles. The catalytic activity and durability of C@NiO/Ni nanofibers containing different weight ratio of Ni salt content (2%, 3%, & 4%) were examined for HER in 1 M KOH solution. It has been observed that C@NiO/Ni nanofibers containing Ni content (4%) showed the highest catalytic activity. It indicates that the catalytic activity of electrocatalyst can be enhanced by increasing the effective active sites. Noteworthy to mention here that the nanofibers catalyst reached a current density of 60 mA/cm2. The as-prepared catalyst showed remarkable stability up to 22 h and retained 99% of its initial activity even after 16 h of reaction.