Role of capping agent on structure, composition and optical properties of ZnO nano-thin films for antibacterial...

In this study, rice extract mediated Zinc Oxide nano thin films were successfully synthesized from Zinc precursors through an eco-friendly, sustainable, and economical method. The synthesized ZnO nano thin films were thoroughly characterized using various analytical and spectroscopic techniques. X-ray diffraction (XRD) analysis confirmed the polycrystalline nature of the synthesized samples with a hexagonal wurtzite crystal structure. The undoped ZnO nano thin films predominantly exhibited the (101) plane, while the rice extract mediated ZnO nano thin films showed a preferred orientation along the (002) plane. The average crystallite size of the sample was estimated to be around 50 nm by XRD analysis. Scanning electron microscopy represent the needle-like structures with improved uniformity on addition 1.5 g rice extract mediated- ZnO thin films. Energy dispersive X-ray analysis proceeds composition of elements presents in the samples. Ultra violet visible spectroscopic measurements showed the shift in value of band gap in between 3.03 and 2.98 eV. Antibacterial studies against Escherichia coli demonstrated a gradual improvement in activity with increasing rice content, with ZOI of 13.33 ± 0.33 mm at 1.5 g mediated thin film. Similarly, enhanced inhibition was observed against Staphylococcus aureus, with the 1.5 g sample showing ZOI of 16.67 ± 0.88 mm.