Solid-State Self-Propagating Combustion Synthesis of Surface Oxidized Copper Nanoparticles and Specific Capacitance Studies

Abstract

In this study, surface-oxidized copper nanoparticles were synthesized through a time and energy-efficient solid-state self-propagating combustion (SSPC) reaction by making use of sodium borohydride (NaBH₄) and calcium carbonate (Cu₂(CO₃)(OH)₂). The microstructure, phase composition, and crystalline structure were examined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) studies. XRD and XPS analyses confirmed the formation of crystalline copper (Cu) and Cu₂O. The percentages of Cu₂O and Cu were calculated to be 13 and 87%, respectively; based on the XRD peak profile. TEM studies confirmed that the Cu nanoparticles (CuNPs) were surface oxidized with a Cu₂O layer of thickness 3–5 nm. Electrochemical studies using a three-electrode setup in a 1 M KOH aqueous solution demonstrated a specific capacitance of 144.44 F/g at 0.15 A/g.