https://repository.auw.edu.bd/handle/123456789/787 Tue, 09 Jun 2026 21:05:45 GMT 2026-06-09T21:05:45Z https://repository.auw.edu.bd/handle/123456789/958 Structural, Morphological, Optical, and Antibacterial Activities of Zinc Oxide Nanopowders: A Comparative Study of Green and Soft Chemical Synthesis Saravanakumar, K. Zinc oxide, a well-known inorganic metal oxide in nanoparticle form, has outstanding antibacterial properties. In this work, the authors focus on determining ZnO nanoparticles’ structural, optical, and antibacterial activity. A simple soft chemical route synthesizes C-ZnO nanoparticles chemically, while the green synthesis method is used to prepare G-ZnO nanoparticles. Ocimum tenuiorum leaf extract was used to prepare G-ZnO nanopowders. ese samples are investigated and compared in terms of their structural, morphological, optical, and antibacterial properties. According to XRD investigations, the synthesized ZnO nano- powders possess a hexagonal structure. e particle size of G-ZnO is smaller than that of C-ZnO nanoparticles. e XPS result revealed the binding and interactions between molecules. e FTIR study conrmed the presence of molecules and their vi- brations. UV-vis-DRS spectroscopy was used to investigate optical properties such as reectance and band gap. e grain size of the G-ZnO nanopowders was decreased, and oxygen vacancy was produced. e antibacterial eciency of plant extracts against two dierent bacterial strains, S. aureus (Gram-positive) and E.coli (Gram-negative), has been studied and reported. Sat, 01 Jan 2022 00:00:00 GMT https://repository.auw.edu.bd/handle/123456789/958 2022-01-01T00:00:00Z https://repository.auw.edu.bd/handle/123456789/957 Ni2+ Ion Sensing by a Semicarbazone Derivative of Piperidin-4-one: A Spectrofluorimetric Study Selvakumare, P. Mosae Nickel ions are toxic to the environment and they are also relevant in biology. Fluorescence sensing is a sensitive method and metal sensing can be carried out employing cheaper and easy-to-synthesize molecules that possess fluorescence emission. Therefore, the development of newer and simply-synthesized chemosensor molecules for nickel ions in aqueous media is required. We report, in this paper, a simple semicarbazone derivative of a piperidin-4-one as a nickel ion sensor in water. The compound forms a 1:1 stoichiometric complex with nickel ions. The association constant value is 4.04 × 104 mol-1 dm3 . The nickel ion-selectivity of the compound is explored employing UV-Vis and fluorescence spectroscopy. Ni2+ ion-chelation enhances the fluorescence of the chemosensor molecule. The Ni2+ detection limit of the chemosensor was 1 × 10-7 mol dm-3 . The compound also forms a 1:2 inclusion complex with β-cyclodextrin. The structure of the complex is proposed. Host: guest complex formation of β-cyclodextrin with the piperidin-4-one derivative results in the interference of the host molecule with the chelation of Ni2+ ions. As an extension of the application of the piperidin-4-one derivative, we demonstrate the Ni(II) ion filtration by incorporating the compound with a polysulfone film. Sat, 01 Jan 2022 00:00:00 GMT https://repository.auw.edu.bd/handle/123456789/957 2022-01-01T00:00:00Z