Browsing by Author "A. Prakasam"

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Effect of La Doping on NiCr2O4Properties and Catalytic Applications toward Decolorization of 4-Nitrophenol
(IOP Publishing Ltd, 2022) G. Rajeswari; N. Prabavathi; A. Prakasam; Rajneesh Kumar; S. Geetha; P. Tamizhdurai; Zeid A. Alothman; Ahmed muteb Aljuwayid; U. Rajaji
We report the successful synthesis of urea as a fuel for low-temperature microwave combustion-based synthesis of NiCr2O4 and La-doped NiCr2O4. Synthesis parameters include the kind of precursor, fuel, and container, as well as how external heat is provided to achieve the combustion reaction. Crystal structures, morphology, surface area, solar cells, Fourier-transform infrared spectrometry, and catalytic activity were used to characterize the products. No impurities phase formed in the as-synthesized NiCr2O4 sample, confirmed by XRD. Surface area was measured with a Brunauer Emmet Teller adsorption isotherm. Schottky and Frenkel formation energies have been investigated. This demonstrates the time needed for full decolorization of 4-Nitrophenol (yellow color) by NiCr2O4 and La-doped NiCr2O4. The La-doped NiCr2O4 (0.03%) showed the greatest catalytic activity compared to pristine and other La-doped NiCr2O4. The decolorization occurs in 10 min. The chemical hardness and surface area of the chromites appear to be important in determining catalytic performance. For multi oxide systems, the counter-doped ions in the A and B sites may alter the metal ion-oxide bond, promoting this partial oxidation process at the interface. The results suggest multiple research subjects focusing on such materials for the future. © 2022 Electrochemical Society Inc.. All rights reserved.
Facile construction of MoS2 decorated CdS hybrid heterojunction with enhanced hydrogen generation performance
(Elsevier B.V., 2024) R. Sridevi; A. Prakasam; P.M. Anbarasan; Rajneesh Kumar; M. Karthik; K. Deepakvijay
Promoting the charge separation to improve photocatalytic performance of semiconductor photocatalysts is very important in the field of artificial photosynthesis. Here, a novel MoS2/CdS 2D–2D ultrathin nanosheet heterostructure was fabricated via a one-pot solvothermal route. The obtained 2D–2D MoS2/CdS nanojunction has not only provided large contact areas, but also shortened the charge transport distance, resulting in significantly enhanced photocatalytic H2 evolution property. The composites that were synthesized were examined using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Transmission electron microscope (TEM), UV-vis diffuse reflectance spectra (DRS), Photoluminescence (PL) and X-ray photoelectron spectra (XPS) analysis. By optimizing the 2D MoS2 amounts in the heterojunction, the 5 wt.% 2D/2D MoS2/CdS heterojunction displayed the maximal photocatalytic H2 evolution rate of 4449 μmolh−1g−1 under visible light irradiation in the presence of lactic acid as the sacrificial reagent, which was 6 times higher than that of pristine 2D CdS. Based on the photoelectrochemical and photoluminescence spectra tests, it could be deduced that the charge separation and transfer of 2D/2D MoS2/CdS heterojunction was tremendously improved, and the recombination of photoinduced electron-hole pairs was effectively impeded. Moreover, the 2D MoS2 was used as a cocatalyst to provide the abundant active sites and lower the overpotential for H2 generation reaction. The current work would offer an insight to fabricate the 2D/2D heterojunction photocatalysts for splitting H2O into H2. © 2024 The Author(s)
Morphologies, crystal structure and antibacterial properties of chromium substituted zinc oxide nanoparticles synthesized by microwave method
(Elsevier Ltd, 2021) A. Prakasam; P.M. Anbarasan; R. Azhagu Raj; C. Ragupathi; Rajneesh Kumar
In this paper, we report on the synthesis on pure and Cr doped ZnO particles via the microwave method. Pure and Cr doped ZnO produced are monodisperse and versatile and were characterized with the help of FT-IR, XRD, SEM/EDX and TEM methods. Pure and Cr doped ZnO particles are crystalline in nature and average sizes were between 20 and 30 nm. Furthermore, the present work clearly indicated that the surface area to volume ratio and particle size variation of green ZnO nanoparticles are accountable for significantly increased antibacterial behaviour. © 2021 Elsevier Ltd. All rights reserved.