Browsing by Author "Thiripuranathar, G."

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Comparative study on the sustainable utilization of banana flowers mediated nanomaterials for pigment dye degradation via photo catalysis
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Gamage, V.; Thiripuranathar, G.; Nishshanka, U.; Priyantha, N.; Goonatilleke, M. D.; Guiton, B. S.; Jayanetti, S.
Dyeing is prevalent in the textile industry; however, they are often harm to the environment. Photodegradation plays a crucial role in dye removal by utilizing nanoparticles (NPs) as catalysts. These NPs effectively break down harmful dyes, thereby significantly reducing their environmental impact. Employing biogenic NPs not only reduces environmental burden associated with waste disposal but also enhances resource efficiency and conservation efforts. This study focuses on synthesizing silver NPs (Ag NPs), zinc oxide NPs (ZnO NPs), and silver-zinc oxide nanocomposite (Ag-ZnO NCs) derived from Banana Flower (BF), with a specific focus on evaluating their photocatalytic efficacy against IC orange pigment dye (PD), a commonly employed textile dye. The optimal conditions for synthesizing Ag NPs, ZnO NPs, and Ag-ZnO NCs with higher yields were identified by varying the conditions, such as ion precursor concentration, ratio of plant extract to ion solution, irradiation methods, pH, and incubation time. UV-Vis spectroscopy, FT-IR, SEM, TEM, EDS, and XRD analyses were utilized to characterize the NPs and NCs. The synthesized NMs were confirmed by surface plasmon resonance peaks: 400-430 nm for AgNPs, 350-360 nm for ZnO NPs, and 350–450 nm for Ag-ZnO NCs. FT-IR analysis identified bioactive compounds in the phytoextracts acting as reducing, capping, and stabilizing agents. Also, the stretching mode of the Zn-O bond in the range of 500–700 cm-1 confirms the synthesis of ZnO NPs. SEM analysis confirmed successful formation of Ag NPs, ZnO NPs, and Ag-ZnO NCs, with a spherical shape, flake, and nanoflower-shaped NMs, respectively. TEM images showed the coexistence of Ag on ZnO for NCs, with an average particle size of 97.1 nm. Further, the BF-mediated Ag NPs and ZnO NPs showed the particle size of 64.6 nm and 84.3 nm, respectively. XRD analysis indicated a hexagonal wurtzite structure for ZnO NPs and a face-centered structure for Ag NPs and both structures were present in Ag-ZnO NCs. The EDS analysis confirmed the chemical elements as Ag for Ag NPs and Zn and O for ZnO NPs while all three elements for NCs. Under the optimum operational conditions (pH, catalytic load, and dye concentration), the BF-mediated NMs were studied for the degradation of PD. The ZnO NPs synthesized using BF demonstrated exceptional photodegradation efficiency of 93.8 % at 7 hours while for Ag NPs and the NCs it was 10.6%, and 87.9 % respectively. This exceptional performance of BF-mediated ZnO NPs are due to the wide-bandgap semiconductor capabilities of the ZnO NPs, aligning with the absorption of solar light. In contrast, Ag NPs have lower photodegradation efficiency because of their less effective charge separation and lower generation of reactive oxygen species. Thus, the findings of this study unveil the promising potential of NMs synthesized with BF as a sustainable solution for advancing textile and wastewater remediation.
Physicochemical properties and antioxidant activity of peel and pulp of 'Karuthacolomban' and 'Willard' cultivars of mango (Mangifera indica L.) in Sri Lanka
(Postgraduate Institute if Science, University of Peradeniya, Sri Lanka, 2015) Kuganesan, A.; Thiripuranathar, G.; Navaratne, A.N.; Paranagama, P.A.