In this work,
zinc oxide particles (ZnO NPs) green synthesis with the application of
black tea extract (BT) is presented. A thorough investigation of the properties of the extract and the obtained materials was conducted by using Fourier transform infrared spectroscopy (FTIR), liquid chromatography-mass spectrometry (LC-MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and quadrupole mass spectroscopy (QMS). The obtained results indicated that the amount of used BT strongly influenced the morphology, chemical, and crystalline structure of the obtained particles. The investigation demonstrated that the substance present in
black tea (BT) extract, which was adsorbed on the ZnO surface, was in fact
gallic acid. It was found that
gallic acid controls the crystallization process of ZnO by temporarily blocking the
zinc cations. Additionally, these organic molecules interact with the
hydroxide group of the precipitant. This blocks the
dehydration process stabilizing the
zinc hydroxide forms and hinders its transformation into
zinc oxide. Performed measurements indicated that obtained ZnO particles have great
antioxidant and antimicrobial properties, which are significantly correlated with ZnO-
gallic acid interactions.