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Subject: search.filters.subject.reduced graphene oxide

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    PublicationOpen Access
    Reduced Graphene Oxide-Based Hybrid Electrospun Nanofibers Doped with Green- Synthesized Silver Nanoparticles: An Antibacterial Wound Healing Scaffold
    (Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Sithumini, A. G. P. M.; Rajapakshe, D. N.; De Silva, N.
    This research focuses on the development of novel antibacterial electrospun fibers composed of polyvinyl alcohol (PVA), hydrolyzed collagen (HC), and reduced graphene oxide (rGO), further modified with silver nanoparticles (AgNPs) for potential wound healing applications. Green synthesis of AgNPs, using a tea extract, was verified by a colour change from yellowish-brown to dark brown and the appearance of a UVVis absorbance peak at 450 nm. Scanning Electron Microscopy (SEM) revealed mostly spherical AgNPs with a primary size distribution between 10 and 50 nm. Energy Dispersive X-ray (EDX) analysis confirmed the presence of Ag atoms (a characteristic peak at 3 keV). Particle size analysis indicated an average AgNP size of 133 nm, with a particle size distribution showing a high-intensity peak at 299 nm and a lower-intensity peak at 18.39 nm, and a polydispersity index (PDI) of 0.471. SEM images of rGO-containing mats showed well-preserved fiber morphology with uniformly distributed AgNPs, in contrast to mats without rGO, where significant AgNP agglomeration covered fiber visibility. This suggests rGO's role in preventing nanoparticle aggregation and enhancing dispersion. Swelling ratio analysis demonstrated superior swelling in rGO-containing mats, reaching 390.48% after 48 hours compared to 273.6% for mats without rGO. The incorporation of rGO improves the antibacterial performance and mechanical properties of the scaffold, while green-synthesized nanoparticles further enhance the antibacterial efficacy.
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    PublicationOpen Access
    Persulfate assisted photocatalytic and antibacterial activity of TiO2–CuO coupled with graphene oxide and reduced graphene oxide
    (https://www.nature.com, 2024-05-31) Thambiliyagodage, C; Liyanaarachchi, H; Jayanetti, M; Ekanayake, G; Mendis, A; Samarakoon, U; Vigneswaran, S
    Photocatalysts of TiO2–CuO coupled with 30% graphene oxide (GO) were hydrothermally fabricated, which varied the TiO2 to CuO weight ratios to 1:4, 1:2, 1:1, 2:1 and 4:1 and reduced to form TiO2–CuO/reduced graphene oxide (rGO) photocatalysts. They were characterized using XRD, TEM, SEM, XPS, Raman, and DRS technologies. TiO2–CuO composites and TiO2–CuO/GO degrade methylene blue when persulfate ions are present. Persulfate concentration ranged from 1, 2, 4 to 8 mmol/dm−3 in which the highest activity of 4.4 × 10–2 and 7.35 × 10–2 min−1 was obtained with 4 mmol/dm−3 for TiO2–CuO (1:4) and TiO2–CuO/GO (1:1), respectively. The presence of EDTA and isopropyl alcohol reduced the photodegradation. TiO2–CuO coupled with rGO coagulates methylene blue in the presence of persulfate ions and such coagulation is independent of light. The catalyst dosage and the concentration of the dye were varied for the best-performing samples. The antibacterial activity of the synthesized samples was evaluated against the growth of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumonia. Ti:Cu (1:2)-GO and Ti:Cu (1:4)-GO had the highest antibacterial activity against K. pneumoniae (16.08 ± 0.14 mm), P. aeruginosa (22.33 ± 0.58 mm), E. coli (16.17 ± 0.29 mm) and S. aureus (16.08 ± 0.88).
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    PublicationOpen Access
    Fabrication of r-GO/GO/α-Fe2O3/Fe2TiO5 Nanocomposite Using Natural Ilmenite and Graphite for Efficient Photocatalysis in Visible Light
    (MDPI, 2023-01) Usgodaarachchi, L; Jayanetti, M; Thambiliyagodage, C; Liyanaarachchi, H; Vigneswaran, S
    Hematite (α-Fe2O3) and pseudobrookite (Fe2TiO5) suffer from poor charge transport and a high recombination effect under visible light irradiation. This study investigates the design and production of a 2D graphene-like r-GO/GO coupled α-Fe2O3/Fe2TiO5 heterojunction composite with better charge separation. It uses a simple sonochemical and hydrothermal approach followed by L-ascorbic acid chemical reduction pathway. The advantageous band offset of the α-Fe2O3/Fe2TiO5 (TF) nanocomposite between α-Fe2O3 and Fe2TiO5 forms a Type-II heterojunction at the Fe2O3/Fe2TiO5 interface, which efficiently promotes electron-hole separation. Importantly, very corrosive acid leachate resulting from the hydrochloric acid leaching of ilmenite sand, was successfully exploited to fabricate α-Fe2O3/Fe2TiO5 heterojunction. In this paper, a straightforward synthesis strategy was employed to create 2D graphene-like reduced graphene oxide (r-GO) from Ceylon graphite. The two-step process comprises oxidation of graphite to graphene oxide (GO) using the improved Hummer’s method, followed by controlled reduction of GO to r-GO using L-ascorbic acid. Before the reduction of GO to the r-GO, the surface of TF heterojunction was coupled with GO and was allowed for the controlled L-ascorbic acid reduction to yield r-GO/GO/α-Fe2O3/Fe2TiO5 nanocomposite. Under visible light illumination, the photocatalytic performance of the 30% GO/TF loaded composite material greatly improved (1240 Wcm−2). Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) examined the morphological characteristics of fabricated composites. X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), X-ray fluorescence (XRF), and diffuse reflectance spectroscopy (DRS) served to analyze the structural features of the produced composites. © 2022 by the authors.