Green synthesis of copper oxide nanoparticles using black, green and tarragon tea and investigation of their photocatalytic activity for methylene blue

In this study, copper oxide nanoparticles (CuO-NPs) were obtained by biosynthesis using aqueous extracts of black tea (BT), green tea (GT) and tarragon tea (TT). The effect of extracts from leaves of plants on the reduction mechanism has been investigated. The amount of polyphenol as using reducing agent in the extracts from the plants was determined according to the Folin-Ciocalteu's method. Total phenolic acid amounts of the extracts of BT, GT and TT were found as 59.18, 42.81 and 49.83 mg/L, respectively. Properties of synthesized CuO-NPs using these extracts were examined by UV-visible spectroscopy, Fourier infrared transformation spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Atomic Force Microscopy (AFM) analysis. In addition, prepared CuO-NPs were used in methylene blue (MB) removal as a photocatalyst. According to AFM results, average size of CuO-NPs was determined ranging from 10 to 12 nm. Regarding photocatalytic activity, prepared CuO-NPs from BT, GT and TT removed 89%, 87% and 90% of dye in 360 min, respectively. In the photocatalytic removal study, the reaction kinetics were investigated with zero, first and second order kinetics.