Facile Synthesis and Characterization of Copper Phosphide Nanoparticles as Efficient Electrocatalyst for Hydrogen and Oxygen Evolution Reaction

Abstract

Electrocatalytic water splitting has been considered as one of the most significant and sustainable approaches for hydrogen production. To make the process more efficient and affordable, there is a need to develop robust, cheap, highly active and stable electrocatalysts. Herein, facile synthesis of copper phosphide nanoparticles (Cu₃P NPs) with size ranging from 30 to 80 nm was carried out by using solvothermal process. Variety of characterization techniques like FTIR, XRD, Raman spectroscopy, dynamic light scattering and SEM–EDX, verified the successful synthesis of Cu₃P NPs with spherical morphology. Three-electrode system containing glassy carbon, platinum mesh and Hg/HgO as working, counter and reference electrode, respectively, was used for the electrochemical characterization. Electrochemical studies, i.e., CV, LSV and chronoamperometric analysis, revealed efficiency and stability of electrocatalyst for electrolysis of water including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Briefly, the Cu₃P NPs exhibited an excellent OER activity, achieving the current density of 10 mA cm⁻² with an overpotential of 450 mV. Tafel slope value 63 mV dec⁻¹ suggested fast OER reaction kinetics. The Cu₃P catalyst also exhibited significant HER activity, approaching a current density of 10 mA cm⁻² with an overpotential of 447 mV. Fast HER reaction kinetics was observed with a Tafel slope value of 132 mV dec⁻¹. Moreover, the chronoamperometric studies revealed the stability of electrocatalyst providing favorable conditions for sustainable, long-term oxygen and hydrogen production.