Vhnsn College Autonomous

Virudhunagar, India

Vhnsn College Autonomous

Virudhunagar, India
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Saravanakumar K.,VHNSN College Autonomous | Karthik R.,National Taipei University of Technology | Chen S.-M.,National Taipei University of Technology | Vinoth Kumar J.,VHNSN College Autonomous | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2017

In this study, we report a series of novel palladium nanoparticles (Pd) supported cerium oxide (CeO2)/graphitic carbon nitride (g-C3N4) nanocomposites, fabricated via the simple strategy, which were used for the detoxification of toxic hexavalent chromium to benign trivalent chromium under visible light irradiation. The synthesized Pd/CeO2/g-C3N4 nanocomposites were characterized by various tools including powder X-ray diffraction (PXRD), fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS/UV–vis), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectra (EDS). The wrapping with surface of graphitic carbon nitride nanosheets can efficiently promote the interface charge separation and transmission over the ternary photocatalyst, which was studied by photoluminescence spectra (PL) analysis and electrochemical impedance spectroscopy (EIS) spectra. The obtained 3% Pd/CeO2/g-C3N4 nanocomposite photocatalyst exhibit an excellent photocatalytic performance when compared to other single and composite counter parts. The 3% Pd/CeO2/g-C3N4 exhibits a strong synergistic effect which arises due to the interactions between palladium nanoparticles, CeO2 and graphitic carbon nitride resulting in the lower recombination of photo-induced charge carriers with enhanced photocatalytic activity. This work implies that the synergistic Pd/CeO2/g-C3N4 nanocomposites would be a new kind of high-efficiency visible-light-driven photocatalysts materials for the detoxification of public safety and security. © 2017 Elsevier Inc.


Jeyakumar S.,Vhnsn College Autonomous | Jeyakumar S.,French Institute of Pondicherry | Jeyakumar S.,University of Lucknow | Ayyappan N.,French Institute of Pondicherry | And 2 more authors.
Tropical Ecology | Year: 2017

Studies on the residual impact of logging on the diversity and composition of tropical forests are scarce in India. We examined the impact of selective logging on tree species richness, composition and structure prevalent after 27 years. Trees ≥ 30 cm girth at breast height were inventoried in four 1 ha plots in selectively logged patches and two 1 ha plots in an adjacent unlogged patch of lowland dipterocarp forest continuum, Uppangala, central Western Ghats, India. We enumerated 2343 trees (598 trees ha-1) belonging to 116 species (63 species ha-1) and 1345 trees (672 trees ha-1) belonging to 68 species (55 species ha-1) in logged and unlogged plots, respectively. The species richness in logged plots as compared to unlogged plots varied with spatial scale of sampling: at 1 ha scale two logged plots had higher species richness whereas it was high in only one plot at 400 m2 scale. Logged plots had low floristic similarity between them and also with the unlogged plots. Mantel and partial Mantel tests proved that logging was the main driver for the species composition rather than the elevation and spatial distance. Higher abundance of species belonging to canopy, intermediate and light wood categories and lower density of emergent, understory and medium wood types were recorded in the logged plots. As compared to unlogged plots, logged plots had 20-59% less above ground biomass (AGB) due to paucity of larger trees, especially in the emergent and medium wood types but higher AGB in canopy and hardwood categories. Our study shows the residual impact of logging even after 27 years and suggests that the recovery process may depend on the resurgence of emergent and medium wood categories. © International Society for Tropical Ecology.


Alfind Paulfrit A.,VHNSN College Autonomous | Pandiarajan J.,VHNSN College Autonomous | Jeyakumaran N.,VHNSN College Autonomous | Prithivikumaran N.,VHNSN College Autonomous
International Journal of ChemTech Research | Year: 2014

Nickel oxide (NiO) thin films have been fabricated by thermal evaporation of nickel metal powder on glass substrate and oxidised through annealing to form nickel oxide thin films. The structural and optical properties of the NiO film annealed at 400°C was examined by X-Ray diffraction (XRD), UV-Visible and Photoluminescence (PL) spectral studies. The XRD analysis of the prepared thin films reveals cubic structure with dominant (1 1 1) orientation. The grain size calculated by using Debye-Scherrer formula was 27 nm. From the XRD analysis the micro strain and the dislocation density was also calculated.The transmittance of the NiO films was 81% at 550nm wavelength. The direct and indirect band gaps derived from Tauc’s plot are 3.61eV and 1.90eV respectively. The room temperature PL spectrum of the NiO thin film show a strong dominant peak at 495 nm along with shoulder peaks at 430nm and 390 nm with excitation at 290nm.These results show that NiO films could be a potential candidate for solar cell applications. © 2014, Sphinx Knowledge House. All rights Reserved.


Subbaraj P.,Devanga Arts College Autonomous | Ramu A.,Madurai Kamaraj University | Raman N.,Vhnsn College Autonomous
Journal of Saudi Chemical Society | Year: 2015

A new bidentate NO type Schiff base ligand (HL), derived from 2-hydroxy-4-methoxyphenyl)phenylmethanone with aniline and its metal(II) [M = Mn, Co, Ni, Cu and Zn] complexes has been synthesized. The synthesized ligand and the metal(II) complexes were structurally characterized by analytical, spectral (FT-IR, UV-vis., 1H NMR, FAB-Mass, TGA/DTA and EPR) as well as molar conductance and magnetic studies. All the complexes are non-electrolytes having 1:2 stoichiometry. They adopt tetrahedral and octahedral geometry. Thermal behavior of metal(II) complexes (1a-1c) shows loss of coordinated water molecules in the first step followed by the decomposition of ligand moieties in a respective manner and leads to form an air stable metal oxide as the final residue. Micro crystalline nature and the presence of coordinated water molecules have been confirmed by powder XRD, SEM and thermal analyses. The ligand and its complexes have efficient bio-efficacy, DNA binding and cleavage ability. © 2014 King Saud University.


PubMed | Manonmaniam Sundaranar University, VHNSN College Autonomous and PSG College of Technology
Type: | Journal: Carbohydrate polymers | Year: 2016

In the present study silver nanoparticles were synthesized by reduction of AgNO


Selvarani M.,VHNSN College Autonomous | Prema P.,VHNSN College Autonomous
Asian Journal of Pharmaceutical and Clinical Research | Year: 2013

Objective: Growing resistance of microorganisms to potent antibiotics has renewed a great interest towards investigating bactericidal properties of nanoparticles and their nanocomposites as an alternative. Therefore, the present study has been carried out to investigate and compare the antibacterial properties of copper (Cu) and zerovalent iron (Fe°) nanoparticles. Methods: Nanoparticles were synthesized by reducing aqueous solution of respective salt solution with sodium borohydride (NaBH4). The synthesized particles were further characterized by X-Ray Diffractogram (XRD), and Scanning Electron Microscopy (SEM) techniques to analyze size and morphology respectively. Antibacterial efficacy of metal nanoparticles was evaluated by agar well diffusion method. Results: Average size of the particles was found to be 17.25 nm (Cu) and 44.87 nm (Fe°). Energy-dispersive spectrum (EDS) of the nanoparticles dispersion confirmed the presence of elemental metals. The mechanism of microorganism inactivation is considered as species-dependent. Pseudomonas aeruginosa exhibited highest antibacterial sensitivity (26.00 ± 0.41 mm) to copper nanoparticles whereas Bacillus cereus offered maximum zone of inhibition (23.33 ± 0.89 mm) to Fe° nanoparticles. Conclusion: Results from this study signify that the Cu and Fe° nanoparticles potentiate the antibacterial action of both gram positive and gram negative bacteria.


Jothi S.,VHNSN College Autonomous | Prithivikumaran N.,VHNSN College Autonomous | Jeyakumaran N.,VHNSN College Autonomous
International Journal of ChemTech Research | Year: 2014

Zirconium Oxide (ZrO2) is an interesting material in optical filters, gas sensors and protective coatings owing to their outstanding optical, chemical, thermal and mechanical properties. Zirconium Oxide thin films were deposited on glass substrates by sol gel dip coating method, using alcoholic solutions. The dipping solution was prepared from Zirconium OxychlorideOctahydrate and Isopropanol with Acetyl acetone. In order to find the influence of the number of layers on the properties of ZrO2 thin films, samples with different number of layers were prepared by repeating the dipping and drying processes. After coating, the sol gel derived films were heated at 500°C, to complete the dehydration of the ZrO2 precursors. Various characterization techniques were used to evaluate the crystalline structure and grain size (XRD), the morphology (SEM), surface bonding properties (FTIR) and luminescence properties (PL) of ZrO2 films. XRD data exhibited that at 500°C temperature nanosized ZrO2 films with tetragonal and monoclinic phases have been formed. FTIR spectra revealed the formation of Zr-O bond. Photoluminescence studies displayed a strong emission peak at 426 nm and relatively weak emission peak at 488 nm.


Prema P.,VHNSN College Autonomous | Iniya P.A.,VHNSN College Autonomous | Immanuel G.,Manonmaniam Sundaranar University
RSC Advances | Year: 2016

Herein, the microbial mediated synthesis of gold nanoparticles (GNPs) was achieved via an easy biological protocol using Klebsiella pneumoniae (MTCC-4030). Gold ions in the reaction mixture were exposed to K. pneumoniae for the formation of colloidal GNPs. The characterization study indicated that the UV-vis spectral analysis of the GNPs showed a peak at 550 nm. XRD spectroscopy of the GNPs confirmed their crystalline nature. Scanning electron images of the GNPs showed that they were spherical in shape and were well dispersed. Atomic force microscopy revealed that the size range of the GNPs was between 10 and 15 nm. The FTIR study revealed the possible involvement of reductive groups on the surface of the nanoparticles. The antibacterial activity of the GNPs showed the highest inhibitory zone (25.60 mm) against Escherichia coli as an indicator strain. The synergistic effect of the GNPs obtained the highest fold increase (4.06) and activity index (3.210) against E. coli, followed by 2.610 activity index against Staphylococcus aureus using amoxycillin and streptomycin as standard antibiotics, respectively. © The Royal Society of Chemistry 2016.


Jothi S.,VHNSN College Autonomous | Prithivikumaran N.,VHNSN College Autonomous | Jeyakumaran N.,VHNSN College Autonomous
International Journal of ChemTech Research | Year: 2014

Zirconium Oxide (ZrO2) thin films were prepared on glass substrates by sol-gel dip coating method using Zirconium Oxychloride Octahydrate, Isopropanol and Acetyl acetone as precursor, solvent and stabilizer respectively. In the present work, the optical properties of the Zirconia thin films have been studied. Samples with different number of layers were prepared by repeating the dipping and drying processes. Then, the sol gel derived films were annealed at 500°C. The crystalline structure of the ZrO2 film was determined using X-ray diffraction. The films found to show tetragonal phases at the annealing temperature of 500°C. The UV-Visible transmission and reflectance spectra were used to observe the optical properties of the thin films. The average refractive index of the thin films was found to be 1.9, calculated using reflectance and transmission spectra. The measured band gap values of the ZrO2 thin films were nearly 4.8 eV. SEM analysis showed that the films have cracked plane morphology, as a result of their contraction during heat treatment. © 2014, Sphinx Knowledge House. All rights reserved.

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