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Rani Angineni Venkataswamy Perala Ramaswamy Kadari Srilekha Pallati Sreenu Kurra Vithal Muga 《印度化学会志》2022,99(6):100495
One of the well-known ways of increasing the visible light absorption capability of semiconducting materials is cation doping. This study aims to use Gd doping to tailor the bandgap energy of K2Ta2O6 (KTO) for photocatalytic degradation of organic pollutants under visible light irradiation. Accordingly, the parent KTO and Gd-doped KTO with different Gd concentrations (K2-3xGdxTa2O6; x = 0.025, 0.05, 0.075 and 0.1 mol%) were synthesized by hydrothermal and facile ion-exchange methods, respectively. The powder XRD, FT-IR, SEM-EDS, TEM-SAED, N2 adsorption-desorption, XPS, UV–Vis DRS, PL and ESR techniques were used to investigate the effect of Gd dopant concentration on the structural and photocatalytic properties of KTO. The photocatalytic activity of these samples was investigated for the photocatalytic degradation of methylene blue (MB) dye in an aqueous solution at room temperature under visible light irradiation. The experimental results show that all Gd-doped KTO samples exhibit enhanced photocatalytic activity compared with parent KTO toward MB degradation. In particular, Gd-KTO obtained by doping of 0.075 mol% shows the highest photocatalytic activity among the Gd-doped samples and the degradation efficiency of MB was 79% after 180 min of visible light irradiation, which is approximately 1.5 times as high as that by parent KTO (53%). In addition, trapping experiments and electron spin resonance (ESR) analysis demonstrated that the hydroxyl radicals (?OH) have played a crucial role in the photocatalytic degradation of MB. The reusability and stability of Gd doped-KTO with a Gd content of 0.075 mol% against MB degradation were examined for five cycles. Based on the present study results, a visible light induced photocatalytic mechanism has been proposed for Gd0075-KTO sample. 相似文献
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Sreenu Kurra Perala Venkataswamy Gundeboina Ravi Chandhiri Sudhakar Reddy Boggu Jaganmohan Reddy Muga Vithal 《无机化学与普通化学杂志》2019,645(5):529-536
Perovskite type oxides, sodium bismuth titanate (Na0.5Bi0.5TiO3), and Ag+, Cu2+, and Sn2+ doped Na0.5Bi0.5TiO3 were prepared by pechini and ion exchange methods, respectively. Photocatalytic activities of these catalysts were tested by decomposition of methylene blue (MB) under visible light irradiation. Results showed that the photocatalytic activity of metal ion doped Na0.5Bi0.5TiO3 was higher than undoped Na0.5Bi0.5TiO3. Relatively high photocatalytic performance of Ag+‐doped Na0.5Bi0.5TiO3 is mainly ascribed to the efficient separation of electron‐hole (e–, h+) pairs, lower bandgap energy and the creation of active hydroxyl radicals ( ? OH). Further, the Ag+‐doped Na0.5Bi0.5TiO3 catalyst showed good reusability up to four cycles. A possible mechanism for the enhanced photocatalytic performance was proposed. The synthesized photocatalysts were characterized by XRD, SEM, EDS, XPS, FT‐IR, and UV/Vis DRS techniques. 相似文献
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[reaction: see text] A novel method for the synthesis of Delta(1)-1,2-diazetines is presented. Diels-Alder cycloaddition of dienophile 4 with five dienes afforded cycloadducts in good to excellent yields. Four of the obtained cycloadducts were converted to the corresponding diazetines. 相似文献
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Zhang F Rick DL Kan LH Perala AW Geter DR LeBaron MJ Bartels MJ 《Rapid communications in mass spectrometry : RCM》2011,25(20):3123-3130
The possible interaction of environmental contaminants with the endocrine system has been an environmental concern since the early 1990s. To examine these interactions test guidelines have been introduced by regulatory agencies to screen for possible endocrine active compounds. One of these guidelines is the EPA's OPPTS 890.1550 [Steroidogenesis (Human Cell Line‐H295R)]. This guideline requires the quantification of two major biomarkers (testosterone and estradiol) in various biological test systems. Traditional quantitation methodologies such as Radioimmunoassay (RIA) and Enzyme‐linked Immunosorbent Assay (ELISA) have been used to quantify low levels of steroids. However, those methodologies have drawbacks such as the radioactive safety, antibody availability, separate assay for each biomarker, and lack of selectivity. In the current study, a rapid and sensitive liquid chromatography/positive atmospheric pressure photoionization tandem mass spectrometry method (LC/APPI‐MS/MS) has been developed and validated for the simultaneous quantitation of testosterone and estradiol in the H295R cell line. Briefly, the media from cultured cells was extracted with dichloromethane (CH2Cl2) containing internal standards of both testosterone‐d3 and estradiol‐13C3; then, the extracted organic layer was concentrated down to dryness. The final residue was derivatized with dansyl chloride solution, and directly analyzed by LC/APPI‐MS/MS. The calibration curves, with concentration ranging from 10 to 2500 pg/mL, were linear with coefficient >0.99. The lower limits of quantitation for both testosterone and estradiol were 10 pg/mL. This method was successfully validated to support requirements of the current EPA Steroidogenesis guideline. This type of method may also provide value for rapid and precise measurements of these two hormones in other in vitro or in vivo test systems. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Komateedi N. Rao Perala Venkataswamy Pankaj Bharali Heon Phil Ha Benjaram M. Reddy 《Research on Chemical Intermediates》2012,38(3-5):733-744
A series of TiO2?CZrO2 supported V2O5 catalysts with vanadia loadings ranging from 4 to 12 wt% were synthesized by a wet impregnation technique and subjected to various thermal treatments at temperatures ranging from 773 to 1,073?K to understand the dispersion and thermal stability of the catalysts. The prepared catalysts were characterized by X-ray powder diffraction (XRD), BET surface area, oxygen uptake, and X-ray photoelectron spectroscopy (XPS) techniques. XRD results of 773?K calcined samples conferred an amorphous nature of the mixed oxide support and a highly dispersed form of vanadium oxide. Oxygen uptake measurements supported the formation of a monolayer of vanadium oxide over the thermally stable TiO2?CZrO2 support. The O 1s, Ti 2p, Zr 3d, and V 2p core level photoelectron peaks of TiO2?CZrO2 and V2O5/TiO2?CZrO2 catalysts are sensitive to the calcination temperature. No significant changes in the oxidation states of Ti4+ and Zr4+ were noted with increasing thermal treatments. Vanadium oxide stabilized as V4+ at lower temperatures, and the presence of V5+ is observed at 1,073?K. The synthesized catalysts were evaluated for selective oxidation of o-xylene under normal atmospheric pressure in the temperature range of 600?C708?K. The TiO2?CZrO2 support exhibits very less conversion of o-xylene, while 12 wt% V2O5 loaded sample exhibited a good conversion and a high product selectivity towards the desired product, phthalic anhydride. 相似文献
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Venkataswamy Perala Jampaiah Deshetti Kandjani Ahmad Esmaielzadeh Sabri Ylias M. Reddy Benjaram M. Vithal M. 《Research on Chemical Intermediates》2018,44(4):2523-2543
Research on Chemical Intermediates - In this work, various transition and rare earth metal ions (M3+; M = Mn3+, Fe3+, La3+, and Pr3+) doped CeO2 solid solutions were prepared by a... 相似文献
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Manasa Sunku Perala Venkataswamy Gaddameedi Hima Bindu Pallati Srilekha M. Srinivas M. Vithal 《欧洲无机化学杂志》2023,26(7):e202200550
Visible light-driven photocatalysis has gained much attention due to its light-harnessing characteristics and is extensively used in wastewater remediation. This paper presents a novel oxygen-deficient manganese antimonate, MnSb2O6-x, with a trirutile structure as an effective visible-light-driven photocatalyst for dye degradation. The synthesized samples were subjected to XRD, UV-Vis DRS, SEM-EDS, Raman, XPS, and PL analyses to study their physic chemical properties. The influence of sequential or single heating during the preparation method on the generation of oxygen vacancies is evaluated using UV-Vis DRS, XPS, ESR, and Raman techniques. The oxygen-deficient MnSb2O6 could achieve up to 85 % of MO degradation in 180 min under visible light irradiation, and its reusability up to six cycles was also investigated. In addition, the mechanism of dye degradation was supported with a scavenger test, and the degradation activities are correlated to the electron-hole pair separation as convinced from the PL spectra. The simple and unique method of oxygen vacancy generation can inspire the development of antimonates with oxygen deficiencies, which have significant scope of application in environmental and energy conservation. 相似文献
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