Abstract

The present study reports the synthesis of Mangifera indica leaf extract mediated copper oxide nanoparticles (CuO NPs) via a biological method. CuO NPs are characterized for crystal structure and crystallite-size determination, absorption peak, particle size and morphological analysis, elemental composition, and functional groups’ identification using XRD, UV-visible spectroscopy, HRTEM, FESEM, EDX, and FTIR. CuO NPs show an absorption peak at a wavelength of 338 nm with a calculated band gap energy of 2.2 eV, using Tauc’s plot. XRD pattern depicts monoclinic phase ~18 nm average crystallite-size NPs. FESEM and HRTEM micrographs confirm the needle shaped CuO NPs with a 5:40 nm aspect ratio. The EDX spectrum, depicting the Cu and O peaks, shows that the particles are free from any type of impurity. FTIR analysis elucidates the role of bioactive chemicals in the extract in the successful formation of CuO NPs. The photoluminescence study reveals the existence of violet, green, orange, yellow and red emission bands. Additionally, CuO NPs exhibit an electrical conductivity of 1.37 × 10 −7 Sm −1 and 5. 31 × 10 −7 Sm −1 at 100 °C and 200 °C. Thus, environmentally friendly, non-toxic, green-synthesized CuO NPs hold significant potential for applications in resistive sensors, solar cells, and optoelectronics devices.