Effect of fine-tuned growth temperature on structural, morphological, and electrical properties of Cu₂O nanoparticles as candidates for supercapacitor applications

Abstract Cuprous oxide (Cu 2 O) nanoparticles are promising candidates for optoelectronic and energy applications owing to their unique p-type semiconducting properties. This study investigates the effects of precisely controlled synthesis temperatures (45°, 55°, 65°, and 75 °C) on the structural, morphological, and electrical characteristics of Cu 2 O nanoparticles synthesized through a coprecipitation method. X-ray diffraction (XRD) analysis confirms high crystallinity with an average crystallite size of approximately 29 nm, while transmission electron microscopy (TEM) reveals an average particle size of about 50 nm. Scanning electron microscopy (SEM) demonstrates a morphological evolution from spherical to cubic structures with increasing aging temperature. The electrical properties were investigated through AC conductivity and dielectric measurements over a temperature range of 300 K to 550 K and frequencies from 100 Hz to 5 MHz. The results show that Cu 2 O nanoparticles enhance supercapacitor performance through their high dielectric constant at low frequencies, improved energy storage capabilities, and increased AC conductivity for efficient charge transport. Their temperature-dependent behavior and ability to minimize energy losses make them ideal candidates for high-frequency and high-temperature applications. This work demonstrates the exceptional dielectric properties of Cu 2 O nanoparticles and their significant sensitivity to subtle changes in growth temperature, enabling the optimization of their characteristics for supercapacitor energy applications and emerging optoelectronic devices.