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71.
Shanmugasundaram Rajasri Shankramma Kalikeri Subramanian Balachandran Kaliyamoorthy Gowthami Ganesamoorthy Thirunarayanan Meenakshisundaram Swaminathan Inbasekaran Muthuvel 《印度化学会志》2022,99(3):100337
Photocatalysis has recently been regarded as one of the most viable technologies for water treatment. Scholars all over the world are focusing on nanocomposites for water treatment for efficient and effective sanitization of bodies of water. Because of their high surface area, high chemical reactivity, excellent mechanical strength, low cost, and nanoscale composite materials have enormous potential to purify water in a various way. In this study, n-type TiO2 was synthesized and tailored to produce a TiO2/BiOI n–p nanocatalyst for enhanced photodegradation of 2,4-dinitrophenol (2,4-DNP) under UV-A and solar light respectively. Because of the formation of a heterojunction between BiOI and TiO2, the photocatalytic activity in TiO2/BiOI absorbs strongly in both the UV and visible regions and it has a lower recombination rate of the e-/h+ pairs. Furthermore, the generation of OH?, O2?– radicals during the oxidation process is attributed to the photodegradation of 2,4-DNP. The results revealed that the TiO2/BiOI manifest outperformed BiOI and TiO2 in terms of photocatalytic function. XRD, BET, HR-SEM-EDX with ECM, HR-TEM, FT-IR, PL, and UV-DRS techniques determined the photocatalyst composition. The HR-SEM images clearly showed that the particles are less than 27 ?nm in size. Thus, nanocomposite materials have played an important role in water purification. 相似文献
72.
73.
Kumaresan Murugan Saravanan Vadivel Sami Ponnusamy Swaminathan Meenakshisundaram 《Research on Chemical Intermediates》2020,46(9):4193-4209
Research on Chemical Intermediates - A green Keggin-type heteropoly-12-tungstophosphoric acid, (H3[PW12O40].12H2O) supported on graphitic carbon nitride g-C3N4 (HPW/g-C3N4-40), was developed for... 相似文献
74.
K. Muthu G. Bhagavannarayana V. Meenatchi S. P. Meenakshisundaram S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2012,108(3):951-958
In this article, the effect of magnesium doping on the properties of bis(thiourea)zinc(II) chloride (BTZC) crystals has been described. The incorporation of Mg(II) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy and quantified by inductively coupled plasma technique. The powder X-ray diffraction and FT-IR spectral analyses indicate that the crystal undergoes considerable stress as result of doping. SEM studies of pure and doped samples indicate the formation of structural defect centers in BTZC crystals. The TG?CDTA studies reveal the purity of the materials, and no decomposition is observed up to the melting point. Improved crystalline perfection by doping is observed by high-resolution X-ray diffraction. High transmittance is observed, and the cutoff ?? is ~295?nm. 相似文献
75.
Rajaram Rajamohan Sundarrajulu Kothai Nayaki Meenakshisundaram Swaminathan 《Journal of inclusion phenomena and macrocyclic chemistry》2012,73(1-4):99-108
The effects of the addition of β-cyclodextrin (β-CDx) on the absorption and emission properties of the 5-aminoisoquinoline (5AIQ) have been investigated in aqueous media. The formation of host–guest inclusion complex with 1:1 stoichiometry was revealed by absorption, steady state and time-resolved emission spectroscopy. The complex formation has also been confirmed by FT-IR spectra and SEM image analysis of the solid inclusion complex between 5AIQ and β-CDx. No significant change was observed in the ground and excited state pKa values in β-CDx medium. Based on photophysical and prototropic characteristics of 5AIQ in β-CDx, the structure of the 1:1 inclusion complex is proposed. 相似文献
76.
V. Ramasamy G. Suresh P. Rajkumar S. Murugesan S. Mullainathan V. Meenakshisundaram 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):381-393
River sediment depositions on the bottom of rivers most frequently consist of sand and gravel particles, which make them particularly
valuable for the building construction. Knowledge of radioactivity present in building material enables one to assess any
possible radiological hazard to mankind by the use of such materials. The natural radionuclide (238U, 232Th and 40K) contents have been analyzed for the recently excavated sediment samples of Cauvery, Vellar, Ponnaiyar and Palaru rivers
with an aim of evaluating the radiation hazard nature. To know the radiological characteristics of the sediment, the different
radiological parameters are calculated. Natural radioactivity level is higher in Palaru river and it is lower in Vellar river
sediments. In all the rivers, concentration of 238U is decreased, and concentrations of 232Th and 40K are increased towards the river mouth. Granulometric analysis shows that the sand is the main constituent in all the river
sediment samples. Content of sand is gradually decreased, and contents of silt and clay are gradually increased towards the
river mouth. Cluster analysis was carried out to find the similarity level between the radioactivity and granulometric measurements.
The radioactivity level of all the four river sediments mainly depends upon the contents of silt and clay. Averages of the
all calculated radiation hazard indices are lower than recommended level in Cauvery, Vellar and Ponnaiyar river sediments.
Therefore, the sediment of the above rivers does not pose any significant radiological threat to the population when it is
used as a building construction material. 相似文献
77.
Abstract
A new mixed crystal K1−x(NH4)xH2PO4 (KADP) of ammonium dihydrogen phosphate (ADP) of ADP–KCl system has been synthesized with x = 0.5 by slow evaporation of the mixture of equimolar aqueous solution at room temperature. Crystal composition determined by single crystal X-ray diffraction analysis reveals that it belongs to the tetragonal system with noncentrosymmetric space group I-42d and it is structurally similar to ADP crystals with the following parameters: a = 7.418(3) ?; c = 7.2284(6) ?; v = 404.63(4) ?3; z = 4. The substitution results in defect centers which influence the physical properties. Mixed crystal has a superior NLO activity, twice that of KH2PO4 (KDP), a well known NLO material and the enhanced NLO activity is rationalized. The structural analysis of KADP and the influence of partial cationic substitution in ADP by K+ ions on the NLO properties are reported. 相似文献78.
Rajamohan R Swaminathan M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):207-212
Spectral characteristics of diphenylamine (DPA) have been investigated in β-cyclodextrin (β-CDx) solution. The formation of the complex was revealed by UV, steady state and time-resolved fluorescence spectroscopy. The stoichiometry of DPA:β-CDx complex, determined using Benesi-Hildebrand equation and Job's continuous variation method is 1:1. The binding constants calculated from various methods are reported. This inclusion complex formation from DPA and β-CDx was also confirmed by the FT-IR spectral study and SEM image analysis of solid complex prepared by co-precipitation method. 相似文献
79.
S. P. Meenakshisundaram S. Parthiban R. Kalavathy G. Madhurambal G. Bhagavannarayana S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2010,100(3):831-837
The influence of heteroaromatic N-base (1,10-phenanthroline) (Phen), a new additive as complexing agent on tris(thiourea)zinc(II)sulphate (ZTS) crystals from aqueous solutions at 30 °C is investigated. Crystals were grown using low concentration of the dopant (0.005 M L?1) in the aqueous growth medium and the growth promoting effect (GPE) is much greater because of an increase in the metastable zone width. High dopant concentration decreases GPE. The crystalline perfection of the grown crystals is quite good both in doped and undoped crystals as evaluated by high-resolution X-ray diffractometry (HRXRD). The diffraction curve of a typical Phen doped as-grown ZTS crystal was observed to contain a single peak indicating that the crystal does not contain any epitaxial layer on the surface or internal structural grain boundaries. Not much variation is observed in FT-IR and XRD of pure and doped ZTS. Phen depresses the NLO efficiency of ZTS. It could be ascribed due to the disturbance of charge transfer in the presence of the dopant. The grown crystals were also characterized by UV–Vis, SEM and TG–DTA techniques. 相似文献
80.
S. Parthiban S. Murali G. Madhurambal S. P. Meenakshisundaram S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2010,100(3):751-756
The influence of doping the transition metal Zn(II) on potassium hydrogen phthalate (KHP) crystals has been studied. A close observation of FT-IR and XRD profiles of doped and undoped samples reveals some minor structural variations. It appears that the crystal undergoes considerable lattice stress as a result of doping the bivalent zinc. Furthermore, the possibility of cation vacancies aroused owing to the substitution of K1+ by Zn2+ could result in a defective crystal system. Energy dispersive spectra reveal the incorporation of Zn(II) in the crystalline matrix of KHP crystals. Differential scanning calorimetry (DSC) and TG-DTA studies reveal the purity of the sample and no decomposition is observed below the melting point. Small quantity additions of Zn(II) enhance the fluorescence intensity of KHP crystals. The doping results in morphological changes and significantly improves the second harmonic generation (SHG) efficiency of the host crystal. 相似文献