Energy Materials & Technology
Prateek Vasudeo Sawant; Mahadev Agatrao Parekar; Avadhut Vasudev Kardile; Yogesh B. Khollam; Latesh Khanderao Nikam; Ravindra Udayrao Mene
Abstract
This research explores the influence of hydrothermal reaction time on the structural, optical and morphological properties of TiO2 nanoparticles. The photocatalytic performance of TiO2 nanoparticles for the degradation of Methylene Blue is also evaluated and a co-relation between reaction time and photocatalytic ...
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This research explores the influence of hydrothermal reaction time on the structural, optical and morphological properties of TiO2 nanoparticles. The photocatalytic performance of TiO2 nanoparticles for the degradation of Methylene Blue is also evaluated and a co-relation between reaction time and photocatalytic efficiency is established. Structural analysis reveals well-defined anatase phases with enhanced crystallinity at extended reaction times. UV-Visible spectroscopy demonstrates a red shift in absorption with increased reaction time, indicative of tuneable optical properties. FE-SEM images show an increase in particle agglomeration with increasing hydrothermal duration. Photocatalytic experiments underline TiO2-12 as the most efficient catalyst, achieving a remarkable 97% degradation within 105 minutes. The Langmuir-Hinshelwood kinetics model elucidates the reaction rate dependence on hydrothermal reaction time, emphasizing the role of synthesis parameters on the photocatalytic activity of TiO2. Moreover, TiO2-12 sample shows an enhanced degradation rate compared to other samples. Based on the findings, a possible mechanism of photocatalytic degradation of Methylene Blue is proposed.
Alka Jaggessar; Prasad KDV Yarlagadda
Abstract
Bacterial infection is a widespread concern for the medical community. With the rise of antibiotic resistant bacteria strains, research has begun to focus on developing bactericidal surfaces as a method of infection control, to reduce society’s dependence on antibiotics. Previous work in this area ...
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Bacterial infection is a widespread concern for the medical community. With the rise of antibiotic resistant bacteria strains, research has begun to focus on developing bactericidal surfaces as a method of infection control, to reduce society’s dependence on antibiotics. Previous work in this area has established hydrothermal synthesis as an effective method of fabricating bactericidal titanium dioxide nanostructures, with structure height statistically correlated to bactericidal efficiency. This study investigates the effect of NaOH concentration, reaction temperature and reaction time on hydrothermally synthesized TiO2 nanostructures. Various TiO2 nanostructured surfaces, morphologies and dimensions were achieved by altering hydrothermal process conditions. This data was used to develop 3 models to predict nanostructure height, as a function of hydrothermal fabrication conditions. The three models are qualitatively validated using statistical data. These models provide a preliminary basis of modelling TiO2 nanostructure growth during hydrothermal synthesis. The findings of this study are significant for the designing of nanostructured surfaces for antibacterial applications, and users of the hydrothermal method for effective and efficient nanostructure fabrication.
Xun Xu; Fangwang Ming; Jinqing Hong; Zhoucheng Wang
Abstract
Graphene-based aerogels with porous structure and three-dimensional (3D) network have attracted plentiful interests recently because they could exhibit as an excellent matrix for various kinds of nanoparticles, thus providing a potential prospect in a variety of applications. In this report, 3D composite ...
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Graphene-based aerogels with porous structure and three-dimensional (3D) network have attracted plentiful interests recently because they could exhibit as an excellent matrix for various kinds of nanoparticles, thus providing a potential prospect in a variety of applications. In this report, 3D composite aerogel with poriferous structure assembly of bismuth tungstate sheets and graphene nanosheets has been prepared by a simple hydrothermal process. The 3D multihole structure of the hybrid aerogel could not only provide enormous surface area, but also facilitate electron transfer and ion transmission which could decrease the electrode internal resistance and consequently improve the capacitive property. As a result, the Bi2WO6/graphene hybrid aerogel achieves a large specific capacitance of 714 F g -1 at the current density of 4 A g -1 . The hybrid aerogel could provide a new method for developing high-performance energy storage materials.
Hanfeng Liang; Xun Xu; Jinqing Hong; Zhoucheng Wang
Abstract
MnFe2O4 nanoplates have been synthesized by a simple hydrothermal method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been employed to characterize the structure and morphology of the ...
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MnFe2O4 nanoplates have been synthesized by a simple hydrothermal method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been employed to characterize the structure and morphology of the as-prepared sample. The results show that the products are plate-like morphology with 100-500 nm in length and 100-200 nm in thickness. Contrast experiments indicate that the formation of the plate-like nanostructure could be ascribed to the effect of citrate complexation. Magnetic measurements at 300 K gave the saturation magnetization and the coercive field of nanoplates 39.2 emu g -1 and 91.5 Oe, respectively. The electrochemical performance as anode material for lithium-ion batteries was further evaluated by cyclic voltammetry (CV), electrochemical impedance and charge-discharge measurements. It was demonstrated that the material could provide an initial reversible capacity of 1067 mAh g -1 at a current density of 0.1 mA cm -2 over the voltage range from 0.5 to 3.0 V.
P. Rosaiah; O. M. Hussain
Abstract
Lithium iron oxide (LiFeO2) cathode material was prepared by using hydrothermal synthesis. The XRD spectrum exhibited predominant (200) orientation peak at 2q= 43.63o corresponding to cubic rock-salt structure with Fm3m space group and the estimated lattice parameter of the sample is 4.176 Å. Electric ...
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Lithium iron oxide (LiFeO2) cathode material was prepared by using hydrothermal synthesis. The XRD spectrum exhibited predominant (200) orientation peak at 2q= 43.63o corresponding to cubic rock-salt structure with Fm3m space group and the estimated lattice parameter of the sample is 4.176 Å. Electric and dielectric properties were studied over a frequency range of 1 Hz – 1 MHz and in the temperature range from 300 K to 573 K. The ionic conductivity of the sample was found to be 1.9 x 10-6 S/m at 373 K. The temperature dependent conductivity was conformed from the Arrhenius relation and the activation energy was found to be 0.39 eV. A mixed, ionic and electronic conduction was observed from the analysis. The electrical conductivity was found to be decreased with increasing temperature. The dielectric properties were analyzed in the framework of complex dielectric permittivity and complex electric modulus formalisms. The evolution of the complex permittivity as a function of frequency and temperature was investigated. Several important parameters such as activation energy, ionic hopping frequency, carrier concentration, ionic mobility and diffusion coefficient etc, were determined.
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