The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yitai Qian - One of the best experts on this subject based on the ideXlab platform.
-
controllable synthesis of mesoporous co3o4 nanostructures with tunable morphology for application in supercapacitors
Chemistry: A European Journal, 2009Co-Authors: Shenglin Xiong, Changzhou Yuan, Xiaogang Zhang, Baojuan Xi, Yitai QianAbstract:Flower power: Various mesoporous Co3O4 architectural structures (see figure) have been successfully prepared through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co3O4 nanosheets was higher than that of Co3O4 microspheres in a KOH electrolyte. Novel and complex mesoporous 2D and 3D architectures of the oxide semiconductor Co3O4, including nanosheets, nearly monodisperse microspheres that are self-assembled from nanosheets, and copper-coin-like nanosheets, have been synthesized through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The influence of different reaction conditions on the morphology of the products has been discussed in detail. The results revealed that the volume ratio of H2O and ethanolamine (EA) play a crucial role in the morphology of the precursor. The thermal decomposition of the corresponding precursor leads to the formation of the mesoporous structure. The products have been characterized by X-ray diffraction techniques, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-reSolution TEM (HRTEM), and Raman spectroscopy. The electrochemical properties of the Co3O4 electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The electrochemical experiments revealed that the specific capacitance of the Co3O4 nanosheets was higher than that of the Co3O4 microspheres in a KOH electrolyte Solution (3 m). Furthermore, the Co3O4 nanosheet electrodes exhibited good rate capabilities, and maintained 93 % of the initial capacity at a current density of 5 mA cm−2 in a KOH (3 m) electrolyte Solution. The results show that Co3O4 nanosheets might have potential applications as electrode materials for supercapacitors.
-
controllable synthesis of mesoporous co3o4 nanostructures with tunable morphology for application in supercapacitors
Chemistry: A European Journal, 2009Co-Authors: Shenglin Xiong, Changzhou Yuan, Xiaogang Zhang, Yitai QianAbstract:Flower power: Various mesoporous Co3O4 architectural structures (see figure) have been successfully prepared through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co3O4 nanosheets was higher than that of Co3O4 microspheres in a KOH electrolyte. Novel and complex mesoporous 2D and 3D architectures of the oxide semiconductor Co3O4, including nanosheets, nearly monodisperse microspheres that are self-assembled from nanosheets, and copper-coin-like nanosheets, have been synthesized through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The influence of different reaction conditions on the morphology of the products has been discussed in detail. The results revealed that the volume ratio of H2O and ethanolamine (EA) play a crucial role in the morphology of the precursor. The thermal decomposition of the corresponding precursor leads to the formation of the mesoporous structure. The products have been characterized by X-ray diffraction techniques, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-reSolution TEM (HRTEM), and Raman spectroscopy. The electrochemical properties of the Co3O4 electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The electrochemical experiments revealed that the specific capacitance of the Co3O4 nanosheets was higher than that of the Co3O4 microspheres in a KOH electrolyte Solution (3 m). Furthermore, the Co3O4 nanosheet electrodes exhibited good rate capabilities, and maintained 93 % of the initial capacity at a current density of 5 mA cm−2 in a KOH (3 m) electrolyte Solution. The results show that Co3O4 nanosheets might have potential applications as electrode materials for supercapacitors.
-
shape controlled synthesis of 3d and 1d structures of cds in a Binary Solution with l cysteine s assistance
Chemistry: A European Journal, 2007Co-Authors: Shenglin Xiong, Chengming Wang, Guifu Zou, Lifeng Fei, Weizhi Wang, Yitai QianAbstract:A facile L-cysteine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D CdS spherical nanostructures constructed from CdS nanorods (or nanopolypods) in a Binary Solution. By controlling reaction conditions such as the molar ratio between Cd(OAc)2 and L-cysteine and the volume ratio of the mixed solvents, the synthesis of various 3D architectural structures and 1D wirelike structures in large quantities can be controlled. This is the first reported case of the direct growth of novel 3D self-assemblies of CdS nanorods (or nanopolypods). The morphology, structure, and phase composition of the as-prepared CdS products were examined by using various techniques (X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), high-reSolution TEM, and Raman spectroscopy). On the basis of the results from TEM studies and our analysis, we speculate that in the present synthesis the L-cysteine dominates nucleation growth and the ethylenediamine (en)-dominated, oriented-assembly process. Interestingly, the products obtained show a gradient evolution in color from light-yellow to dark-yellow, which implies that their intrinsic optical properties change, possibly due to variations in their special morphologies and structures. This facile Solution-phase L-cysteine-assisted method could be extended for the controlled preparation of other metal chalcogenides nanostructures with complex morphologies.
Chandrajit Balomajumder - One of the best experts on this subject based on the ideXlab platform.
-
simultaneous adsorption of cr vi and phenol from Binary mixture using iron incorporated rice husk insight to multicomponent equilibrium isotherm
International Journal of Chemical Engineering, 2016Co-Authors: Ankur Gupta, Chandrajit BalomajumderAbstract:Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and Binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from Binary Solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic Binary Solution of Cr(VI) and phenol was found to be 36.3817 mg g−1 for Cr(VI) and 6.569 mg g−1 for phenol, respectively.
-
simultaneous removal of cr vi and phenol from synthetic Binary Solution using consortium culture of bacillus sp and e coli immobilized on tea waste biomass in packed bed reactor
Korean Journal of Chemical Engineering, 2016Co-Authors: Ankur Gupta, Chandrajit BalomajumderAbstract:A continuous bio column reactor was designed for the simultaneous bioaccumulation of Cr(VI) and biodegradation of phenol from their Binary synthetic Solution with the ratio of (2: 1). Consortium culture of Bacillus sp. and Escherichia coli was immobilized onto tea waste biomass in the packed bed column. The metabolites formed during the biodegradation of phenol by Bacillus sp. were utilized by Escherichia coli for the bioaccumulation of Cr(VI). The considerable effect of empty bed contact time (EBCT), bed height (cm) and flow rate (mL/min) was investigated onto the simultaneous removal of Cr(VI) and phenol in the column reactor. However, after 3-4 days of continuous treatment of Cr(VI) and phenol the effect of these process parameters was not significant. Dissolved oxygen (DO) of effluent has been found to decrease with run time of packed bed column. The pH of the effluent decreased initially for 2 days but after that it became the same as the influent. A mass transfer study was carried out to calculate the pseudofirst-order rate constant for Cr(VI) and phenol, which was in good agreement with experimental results.
-
simultaneous removal of cr vi and phenol from Binary Solution using bacillus sp immobilized onto tea waste biomass
Journal of water process engineering, 2015Co-Authors: Ankur Gupta, Chandrajit BalomajumderAbstract:Abstract In this investigation, simultaneous Cr(VI) reduction and phenol degradation from contaminated water using Bacillus sp. immobilized onto the surface of tea waste biomass have been studied in a batch reactor. It was observed that Bacillus sp. utilized phenol as a carbon source for Cr(VI) reduction. Optimal conditions were achieved at a biomass dosage of 15 g/L with an initial concentration of 100 mg/L of Cr(VI) and 50 mg/L of phenol. The maximum uptake capacity of Cr(VI) and phenol onto tea waste biomass surface was 741.389 mg/g and 7.761 mg/g, respectively. The equilibrium condition was reached after 27 h for phenol and 48 h for Cr(VI). Multicomponent isotherm models were used to determine the adsorption mechanism for both Cr(VI) reduction and phenol degradation. Non-modified competitive Redlich–Peterson was found to be the best fit for Cr(VI) sorption while extended Langmuir was followed in the case of phenol degradation. Moreover, the experimental results revealed that both Cr(VI) and phenol were well described by the pseudo second-order model.
-
simultaneous co adsorptive removal of phenol and cyanide from Binary Solution using granular activated carbon
Chemical Engineering Journal, 2013Co-Authors: Bhumica Agarwal, Chandrajit Balomajumder, Prabhat Kumar ThakurAbstract:The present study deals with the equilibrium, kinetic and thermodynamic modeling of simultaneous co-adsorption of phenol and cyanide from Binary Solution onto Granular Activated Carbon (GAC). The effect of process parameters like pH, temperature, adsorbent dose and contact time on the adsorptive efficiency has been evaluated. At an optimum pH 8, temperature 30 °C and adsorbent dose of 30 g/L, 79.9% of 200 mg/L phenol and 93.6% of 20 mg/L cyanide were removed. Four multicomponent isotherms were applied to the experimental data conducted at an initial concentration range of 100–1000 mg/L. Single component isotherms viz. Langmuir and Freundlich were applied to determine the multicomponent isotherm parameters. It was found that phenol adsorption followed extended Langmuir isotherm while cyanide adsorption followed extended Freundlich isotherm in multicomponent system. The monolayer adsorption capacity of GAC was found to be 269.7 and 1.95 mg/g for phenol and cyanide, respectively as calculated by extended Langmuir isotherm. Adsorption of phenol and cyanide followed pseudo-second order kinetics indicating chemisorption to be the mechanism of adsorption. Thermodynamic parameters viz., ΔG0, ΔH0 and ΔS0 were −3.5174 KJ/mol, −10.326 KJ/mol, −0.0225 KJ/mol-K for phenol and −6.5575 KJ/mol, 14.044 KJ/mol and 0.0679 KJ/mol-K for cyanide adsorption, respectively. Thermodynamic studies established the process of phenol adsorption onto GAC as exothermic and spontaneous in nature while of cyanide as endothermic in nature.
Shenglin Xiong - One of the best experts on this subject based on the ideXlab platform.
-
controllable synthesis of mesoporous co3o4 nanostructures with tunable morphology for application in supercapacitors
Chemistry: A European Journal, 2009Co-Authors: Shenglin Xiong, Changzhou Yuan, Xiaogang Zhang, Baojuan Xi, Yitai QianAbstract:Flower power: Various mesoporous Co3O4 architectural structures (see figure) have been successfully prepared through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co3O4 nanosheets was higher than that of Co3O4 microspheres in a KOH electrolyte. Novel and complex mesoporous 2D and 3D architectures of the oxide semiconductor Co3O4, including nanosheets, nearly monodisperse microspheres that are self-assembled from nanosheets, and copper-coin-like nanosheets, have been synthesized through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The influence of different reaction conditions on the morphology of the products has been discussed in detail. The results revealed that the volume ratio of H2O and ethanolamine (EA) play a crucial role in the morphology of the precursor. The thermal decomposition of the corresponding precursor leads to the formation of the mesoporous structure. The products have been characterized by X-ray diffraction techniques, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-reSolution TEM (HRTEM), and Raman spectroscopy. The electrochemical properties of the Co3O4 electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The electrochemical experiments revealed that the specific capacitance of the Co3O4 nanosheets was higher than that of the Co3O4 microspheres in a KOH electrolyte Solution (3 m). Furthermore, the Co3O4 nanosheet electrodes exhibited good rate capabilities, and maintained 93 % of the initial capacity at a current density of 5 mA cm−2 in a KOH (3 m) electrolyte Solution. The results show that Co3O4 nanosheets might have potential applications as electrode materials for supercapacitors.
-
controllable synthesis of mesoporous co3o4 nanostructures with tunable morphology for application in supercapacitors
Chemistry: A European Journal, 2009Co-Authors: Shenglin Xiong, Changzhou Yuan, Xiaogang Zhang, Yitai QianAbstract:Flower power: Various mesoporous Co3O4 architectural structures (see figure) have been successfully prepared through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co3O4 nanosheets was higher than that of Co3O4 microspheres in a KOH electrolyte. Novel and complex mesoporous 2D and 3D architectures of the oxide semiconductor Co3O4, including nanosheets, nearly monodisperse microspheres that are self-assembled from nanosheets, and copper-coin-like nanosheets, have been synthesized through a facile Binary-Solution route and sequential thermal decomposition at atmospheric pressure. The influence of different reaction conditions on the morphology of the products has been discussed in detail. The results revealed that the volume ratio of H2O and ethanolamine (EA) play a crucial role in the morphology of the precursor. The thermal decomposition of the corresponding precursor leads to the formation of the mesoporous structure. The products have been characterized by X-ray diffraction techniques, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-reSolution TEM (HRTEM), and Raman spectroscopy. The electrochemical properties of the Co3O4 electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The electrochemical experiments revealed that the specific capacitance of the Co3O4 nanosheets was higher than that of the Co3O4 microspheres in a KOH electrolyte Solution (3 m). Furthermore, the Co3O4 nanosheet electrodes exhibited good rate capabilities, and maintained 93 % of the initial capacity at a current density of 5 mA cm−2 in a KOH (3 m) electrolyte Solution. The results show that Co3O4 nanosheets might have potential applications as electrode materials for supercapacitors.
-
shape controlled synthesis of 3d and 1d structures of cds in a Binary Solution with l cysteine s assistance
Chemistry: A European Journal, 2007Co-Authors: Shenglin Xiong, Chengming Wang, Guifu Zou, Lifeng Fei, Weizhi Wang, Yitai QianAbstract:A facile L-cysteine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D CdS spherical nanostructures constructed from CdS nanorods (or nanopolypods) in a Binary Solution. By controlling reaction conditions such as the molar ratio between Cd(OAc)2 and L-cysteine and the volume ratio of the mixed solvents, the synthesis of various 3D architectural structures and 1D wirelike structures in large quantities can be controlled. This is the first reported case of the direct growth of novel 3D self-assemblies of CdS nanorods (or nanopolypods). The morphology, structure, and phase composition of the as-prepared CdS products were examined by using various techniques (X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), high-reSolution TEM, and Raman spectroscopy). On the basis of the results from TEM studies and our analysis, we speculate that in the present synthesis the L-cysteine dominates nucleation growth and the ethylenediamine (en)-dominated, oriented-assembly process. Interestingly, the products obtained show a gradient evolution in color from light-yellow to dark-yellow, which implies that their intrinsic optical properties change, possibly due to variations in their special morphologies and structures. This facile Solution-phase L-cysteine-assisted method could be extended for the controlled preparation of other metal chalcogenides nanostructures with complex morphologies.
Marc Garland - One of the best experts on this subject based on the ideXlab platform.
-
combining in situ ftir spectroscopy btem analysis bulk density measurements and dft for two diels alder reactions a general approach for partial molar volume and reaction volume analyses
RSC Advances, 2014Co-Authors: Martin A Tjahjono, Gao Feng, Martin Wijaya Hermanto, Foo Cechao, Marc GarlandAbstract:Two organic reactions, namely the reaction of cyclopentadiene (CPD) and dimethyl acetylene dicarboxylate (DMAD) and the dimerization reaction of CPD were conducted in toluene at 298.1 K at atmospheric pressure and measured by in situ FTIR spectroscopy. Band-target entropy minimization (BTEM) analyses were employed for obtaining the pure component spectra of the solutes and their corresponding concentrations. The solute concentrations and the bulk density data were used to evaluate the partial molar volumes of the solute constituents. The partial molar volumes evaluated from this multi-component approach were in good agreement with those determined from independent Binary Solution measurements. The corresponding volumes of reaction for the CPD + DMAD and dimerization CPD + CPD reactions were determined to be −37 ± 3 cm3 mol−1 and −31 ± 2 cm3 mol−1, respectively. For completeness, DFT calculations were performed and used to rationalize the vibration modes corresponding to the BTEM spectral estimates as well as to provide predictions of the molar volumes of the solutes. The present study demonstrates the usefulness of a combined spectroscopic, signal processing, bulk density measurement and DFT approach to the determination of partial molar volumes and volumes of reaction directly from the multi-component reactive systems.
-
self association of acetic acid in dilute deuterated chloroform wide range spectral reconstructions and analysis using ftir spectroscopy btem and dft
Journal of Physical Chemistry A, 2010Co-Authors: Martin Tjahjono, Shuying Cheng, Marc GarlandAbstract:The Binary Solution of acetic acid in CDCl3 was studied at room pressure on the interval T = 293−313 K with a series of acetic acid concentrations up to 0.16 M. In-situ Fourier transform infrared (FTIR) spectroscopy measurements on the interval of 400−3800 cm−1 were utilized as the analytical method to monitor the spectral changes due to self-association of acetic acid. The band-target entropy minimization (BTEM) algorithm was employed to reconstruct the underlying pure component spectra. Analysis successfully provided two major spectral estimates of acetic acid, namely, the monomer (primarily in the form of monomer−CDCl3 complex) and the centrosymmetric cyclic dimer. In addition, analysis provided one minor spectral estimate containing signals from both noncyclic dimers and higher aggregates. Also, spectral estimates were obtained for phosgene and water which were present at trace levels even though considerable precaution was taken to conduct the experiments under anhydrous and anaerobic conditions. Den...
William E Acree - One of the best experts on this subject based on the ideXlab platform.
-
comments on density viscosity surface tension and intermolecular interaction of triethylene glycol and 1 2 diaminopropane Binary Solution its potential downstream usage for bioplastic production
Journal of Molecular Liquids, 2020Co-Authors: William E AcreeAbstract:Abstract A polemic is given regarding several of the calculated numerical values in the published paper. The authors' calculated apparent molar volumes for triethylene glycol and 1,2-diaminopropane cannot be calculated from the measured densities and the mole fraction compositions. Moreover, it appears that the authors may have switched the calculated partial molar volumes of triethylene glycol and 1,2-diaminopropane in Table S5 of the accompanying Supporting information.