Hydrothermally synthesized Ni₃V₂O₈ nanoparticles with horny surfaces for HER and supercapacitor application

This paper describes the hydrothermal synthesis of Ni₃V₂O₈ nanoparticles for supercapacitor and hydrogen evolution study. The surface microstructure of Ni₃V₂O₈ nanoparticles reveals an excellent areal-specific capacitance of 1.09 F cm⁻² at a current density of 1 mA cm⁻² and an energy density of 24 mWh cm⁻² at a power density of 200 mW cm⁻². In addition to supercapacitor performance, the Ni₃V₂O₈ electrode revels well in hydrogen evolution reaction in 1 M KOH electrolyte. The Ni₃V₂O₈ electrode exhibits a 175 mV over potential at 10 mA cm⁻² current density and a 154 deg/mV Tafel slope before stabilization. According to the electrochemical impedance spectroscopy, the series resistance (R_s) is 3.89 Ω and the charge transfer resistance (R_ct) is 5.62 Ω. The series resistance of the Ni₃V₂O₈ electrode is the same, but R_ct climbs to 6.45 Ω after 5 h of stability.