Studies on catalytic degradation of organic pollutants and anti-bacterial property using biosynthesized CuO nanostructures

Abstract Metal oxide nanostructures have become an inevitable class of materials explored for the environmental and biomedical applications. Thus there is a budding demand to develop a method that purge the need of toxic chemicals. It is a report on a novel and eco-friendly method for the rapid synthesis of copper oxide (CuO) nanostructures using Psidium guajava leaf extract. The synthesis route follows green protocols and exploits the phytochemicals present in the leaves. These nanostructures have been characterized by XRD, UV–vis spectroscopy, FTIR spectroscopy and TEM. BET specific surface area analysis reveals the information of availability of active surface sites in CuO nanostructures. Particle size obtained from XRD, TEM and BET studies are found to be ~ 17–20 nm. The XRD pattern, UV absorption at 270 nm and the characteristic IR bands in the region from 400 to 600 cm − 1 confirms the formation of nanostructured CuO. The catalytic activity of the synthesized CuO nanostructures has been evaluated by monitoring the degradation of the dyes methylene blue, methyl orange, methyl red and eosin yellow. The synthesized CuO nanostructures could also very effectively catalyze the reduction of the pollutants 2-NP, 3-NP and 4-NP to the corresponding amino compounds. The degradations are observed to be complete within 4–12 min. Anti-microbial activity of CuO nanocrystals against E. coli and S. aureus has also been assessed by agar well diffusion method. This study provides a promising route for the facile and cost-effective synthesis of bio-active CuO nanocatalysts which could find applications in biomedical field and waste water management.