Green synthesis of ZnO nanoparticles by pineapple peel extract from various alkali sources

ABSTRACT Zinc oxide nanoparticles (ZnO NPs) are concerned as potential materials due to their wide-ranging applications. The green synthesis of ZnO NPs using of plant extract as capping agent has been attracted much of interest of reserachers. Pineapple peel wastes are aboundance in Thailand and its extract contained high levels of phytochemical compounds (flavonoids and their derivatives). In this study, pineapple extract was used as a capping agent in ZnO NP synthesis, and KOH and a lye solution were used as reducing agents for comparison. The XRD patterns exhibit pure-phase ZnO with high crystallinity. The averages of the most petite crystalline sizes obtained from the Scherrer equation calculation of the prepared ZnO powder are 64.61 and 65.41 nm for KOH solution and lye use, respectively. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of ZnO particles and pineapple extract residue in the as-received powder. Scanning electron microscope (SEM) images and transmission electron microscope (TEM) images showed the nano-size of the synthesized particles. The flower-like ZnO-NPs from a 0.06 M zinc precursor and KOH solution exhibited fascinating optical properties. Finally, all the results showed that lye from wood ash could be applied in ZnO nanoparticle synthesis using pineapple peel extract.