Research Publications
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Publication Embargo Development of DSSC Counter Electrode Using PEDOT: PSS/GO Nanocomposite(SLIIT, Faculty of Engineering, 2024-10) Ravindran, N. S; Wijayarathne, W. M. K. B. N; Chandrika, R. P.; Medagedara, A. D. T.; Kumara, G. R. A; Bandara, T. M. W. J.Dye-sensitized solar cells (DSSCs) have garnered considerable research interest owing to their ability to achieve high photo-to-electric energy conversion efficiencies at a relatively low production cost. While platinum has been recognized for its exceptional electrocatalytic performance and efficiency as a counter electrode in DSSCs, its higher cost and vulnerability to corrosion have prompted the exploration of alternative materials to replace Pt in this role. DSSCs have demonstrated noteworthy photovoltaic performances by employing a range of candidate materials, including conducting polymers, carbon materials, and nanocomposites of conducting polymers and carbon materials, as counter electrodes. The motivation to form composites or hybrids with nanomaterials stems from the aim to improve the overall photovoltaic efficiency in DSSCs. The main objective of this study was to fabricate a DSSC utilizing a counter electrode comprised of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate and graphene oxide (PEDOT: PSS/GO). The fabrication of the counter electrode involved depositing the PEDOT: PSS/GO nanocomposite onto a graphite sheet using drop casting. The GO, which was synthesized through a modified version of Hummer’s method, underwent characterization via Raman spectroscopy and XRD analysis to ensure a successful synthesis process. The surface morphology and the Raman spectra of coated nanocomposites indicated the good dispersion of GO and the strong interaction between GO and the PSS chain, respectively. In the fabrication process of the DSSC, a gel polymer electrolyte was incorporated between a five-layer TiO2-based photoanode and the PEDOT: PSS/GO-based counter electrode. Photovoltaic performances of DSSCs were evaluated under simulated solar irradiance of 1000 W m-2. They were able to achieve a power conversion efficiency of 2.7%, Voc of 0.73 mV, Jsc of 5.21 mA cm-2, and a fill factor of 0.71.Publication Open Access Photocatalytic activity of Go/Fe3O4 fabricated by Sri Lankan graphite under visible light irradiation(Faculty of Science, University of Kelaniya, Sri Lanka, 2021-10) Usgodaarachchi, L; Thambiliyagodage, C. JGraphene oxide (GO) was synthesized using Sri Lankan naturally available graphite by modified Hummer’s method. Fe3O4 nanoparticles were synthesized successfully by co-precipitation of Fe3+ and Fe2+ in a 2:1 molar ratio via the addition of NH4OH. Magnetically separable GO/Fe3O4 nanocomposite was fabricated by synthesizing Fe3O4 nanoparticles in the presence of GO. The synthesized nanocomposites were characterized by X-ray diffractometry (XRD), Scanning electron microscopy (SEM), and FT-IR spectroscopy. The formation of GO was confirmed by the C(002) peak at 9.39° in the XRD pattern. XRD pattern of the nanoparticles confirms the formation of crystalline Fe3O4 nanoparticles, and the diffraction peak corresponds to graphene oxide disappear in the GO/ Fe3O4 due to the absence of the folded structure of graphene oxide. SEM image of GO shows the crumpled and wrinkled lamellae structure of graphene oxide, and the images of GO/ Fe3O4 show the distribution of Fe3O4 nanoparticles with an average size of 107 nm on GO where the folded structure of GO was not present while restacking of the nanosheets, was observed. FT-IR spectrum of GO shows the presence of polar oxygenated functional groups such as carboxylic acid (-COOH), hydroxyl (-OH), and epoxy (-COC-). The photocatalytic performance of the photocatalysts was evaluated on photodegradation of methylene blue under visible light irradiation. The GO/ Fe3O4 shows better adsorption behaviour and excellent photocatalytic activity where it could be successfully used for three cycles without significant activity loss. The rate constant for the degradation of MB (0.0187 min-1 ) at the first cycle decreased to 0.0101 min-1 at the third cycle. The conversion of MB decreased from 98.31% at the first cycle to 92.15% at the third cycle. The drop in the conversion is only 6.16% going from cycle 1 to 3, which could be due to the accumulation of the MB molecules at the pore structure. The obtained high photocatalytic activity could be due to the enhanced charge separation resulted due to the presence of GO sheets and better interactions between GO and Fe 3O4.Publication Embargo Activity enhanced TiO2 nanomaterials for photodegradation of dyes-A review(Elsevier, 2021-12-01) Thambiliyagodage, C. JWastewater generation due to anthropogenic activities has become a tremendous problem that the world is struggling to solve. Dyes release to normal water reservoirs badly impacts the environment causing severe issues. Removal of dyes from wastewater streams is important. The advanced oxidation process is advantageous as the dye molecules are degraded into harmless species. TiO2 is the most promising semiconductor that has been researched. However, the use of it in the visible range is restricted due to its high band gap (3.0 eV). TiO2 has been modified in order to enhance visible light sensitivity. This review mainly focused on the effects of doping TiO2 with metals and non-metals and coupling with metal and non-metal oxides to improve its efficiency in photodegrading dyes. TiO2 doped with Fe, Cu and Ag as the main metal species, N, S, and C as the main non-metals are summarized. Further, the effect of doping with multi non-metals and co-doping of metals and non-metals are also discussed. Moreover, coupling TiO2 with metal oxides and graphene oxide for enhanced photocatalytic activity is also summarized in this review.