Green synthesis of pure copper oxide nanoparticles using Quercus infectoria galls extract, thermal behavior and their antimicrobial effects

Abstract

In this work, a facile and fast green synthesis of highly stable and well-dispersed copper oxide nanoparticles (CuO-NPs) was successfully carried out using aqueous extract of galls of Quercus infectoria (Q. infectoria) as a reducing and capping agent along with ultrasonic irradiation. XRD pattern indicated the formation of the end-centered monoclinic structure of highly pure CuO-NPs with a crystallite size of 30 nm. SEM image of CuO-NPs exhibited spherical morphology with an average size of 20 nm. Energy-dispersive X-ray spectroscopy clearly demonstrated the presence of copper and oxygen elements that confirms the purity of biosynthesized copper oxide nanoparticles. TEM image revealed that the morphology of CuO-NPs was spherical. Antibacterial activity of the Q. infectoria galls extract and CuO-NPs was evaluated against two Gram-positive bacteria and four Gram-negative bacteria. The novelty of this study is that for the first time galls of Q. infectoria were used for the synthesis of CuO-NPs. The results confirmed that CuO-NPs have been successfully synthesized in a fast, cost effectively, eco-environmentally friendly, nontoxic and also easy method. Antibacterial assays revealed that CuO-NPs are potentially a good source of antimicrobial activity and demonstrating its importance for applying in biomedicine, packaging and general usage such as battery and ceramics.