Electrodeposited Nickel/Chromium(III) Oxide Nanostructure-Modified Pencil Graphite Electrode for Enhanced Electrocatalytic Hydrogen Evolution Reaction Activity

Electrolysis of water in acidic solutions is typically used in the production of electrocatalytic hydrogen. Herein, we proposed the electrochemical fabrication of the nickel/chromium(III) oxide (Ni/Cr 2 O 3 ) nanostructure-modified pencil graphite electrode (PGE) for use as an electrode in hydrogen evolution reaction (HER) in 0.5 M sulfuric acid solution. The optimal combination of nanostructures was determined based on the highest electrocatalytic performance for HER. After determining the ideal experimental conditions for fabrication of Cr 2 O 3, Ni nanoparticles were electrochemically deposited on the Cr 2 O 3 nanostructure-modified PGE to prepare a low-cost electrocatalyst. The Ni/Cr 2 O 3 nanostructure-modified PGEs were characterized through X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Linear sweep voltammetry, Tafel polarization curves, and electrochemical impedance spectroscopy were used for determining H + reduction (Had formation) in acidic solution on modified and unmodified electrode surfaces. This study involves the fabrication of a low-cost, stable, and highly electroactive electrode material for hydrogen production in the electrolysis of water.