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CdO-Fe3O4 nanocomposite with enhanced magnetic and photocatalytic properties

Abstract

Pure CdO nanopowder and CdO-Fe3O4 nanocomposite were synthesized by a cost effective chemical method, and the samples were characterized by XRD, SEM, TEM, FT-IR, UV-Vis-NIR and PL. Also, magnetic and photocatalytic properties of the synthesized samples were studied. XRD patterns of the composite confirm the presence of diffraction peaks related to both CdO and Fe3O4. EDX spectrum confirms the presence of the elements Cd, O and Fe in the composite. Peaks related to Cd–O and Fe–O bonds were observed respectively at 688 cm−1 and 592 cm−1 in the FT-IR spectrum. The paramagnetic behavior of pure CdO becomes ferromagnetic when coupled with Fe3O4. The composite exhibited a high photodegradation efficiency of 92.85 % against the degradation of methylene blue dye under visible light radiation.

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Structural, thermal and optical investigation of tin sulfide nanoparticles for next-generation photovoltaic applications

Abstract

We report a simple approach for synthesizing monodispersed, crystalline and size-tunable tin sulfide nanoparticles for environment friendly next generation solar cell applications. Both SnS and SnS2 nanoparticles could be a potential nanomaterial for solar cells. The structural, morphological, thermal and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS) and Fourier transform infrared spectroscopy (FT-IR). The XRD spectra revealed hexagonal and orthorhombic phases of SnS and SnS2 nanoparticles, respectively, where the grains size ranged from 11 nm to 30 nm. The weight percentage as a function of temperature was determined using TGA analysis. Functional groups were observed by FT-IR. The energy bandgap was determined as 1.41 eV showing usefulness of the nanoparticles in next generation environmental friendly solar energy applications.

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Synthesis of maghemite (γ-Fe2O3) nanoparticles by thermal-decomposition of magnetite (Fe3O4) nanoparticles

Abstract

In this research work, we prepared γ-Fe2O3 nanoparticles by thermal-decomposition of Fe3O4. The Fe3O4 nanoparticles were synthesized via co-precipitation method at room temperature. This simple, soft and cheap method is suitable for preparation of iron oxide nanoparticles (γ-Fe2O3; Fe3O4). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer and differential scanning calorimeter (DSC). The XRD and FT-IR results indicated the formation of γ-Fe2O3 and Fe3O4 nanoparticles. The TEM images showed that the γ-Fe2O3 and Fe3O4 were spherical, and their size was 18 and 22 nm respectively. Magnetic properties have been measured by VSM at room temperature. Hysteresis loops showed that the γ-Fe2O3 and Fe3O4 nanoparticles were super-paramagnetic.

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Studies of Zn-Al-Ce mixed oxides as catalysts for diesel soot combustion

Studies of Zn-Al-Ce mixed oxides as catalysts for diesel soot combustion

A series of Zn-Al-Ce mixed oxides was synthesized by a co-precipitation method. The obtained samples were characterized with respect to composition (XRF), structure (XRD, FT-IR) and texture (BET). Zn-Al-Ce mixed oxides were tested as catalysts of diesel soot combustion. The best catalytic activity was found for Zn2Ce oxide system, which operated in the temperature range of 350-500°C.

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Factors influencing preparation of polyaniline doped with hydrochloric acid

Abstract

Factors influencing the reaction of chemical polymerization during aniline doping with hydrochloric acid (HCl) have been studied in this work. The optimal parameters for the preparation of polyaniline were determined as follows: aniline concentration - 4 mass %, molar ratios of oxidant (NH4)2S2O8:aniline - 1.2:1 and 1.3:1, the concentration of dopant - 1 mol/L. Fourier transform infrared spectroscopy (FT-IR) was applied to characterize the structure of polyaniline.

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Synthesis, Characterization and Synthetic Applications of Fly-ash:H3PO4 Nanocatalyst

Abstract

The solid acidic nanocatalyst fly-ash:H3PO4 was prepared and characterized by FT-IR, SEM, EDS and TEM analysis. This catalyst was utilized for aldol condensation, coupling and cyclization reaction. The effect of catalytic activity of this fly-ash:H3PO4 nanocatalyst was studied with the obtained yield of products under solvent-free conditions. In this synthetic reaction the obtained yields were more than 95 %.

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Chemical modification of alginic acid by ultrasonic irradiation

]. Pereira, L., Sousa, A., Coelho, H., Use of FTIR, FT-Raman and 13C-NMR spectroscopy for identification of some seaweed phycocolloids, Biomolecular Engineering. 2003, 20, 223-228 [22]. Sartori, C, Finch, D. .S, Ralph B., Gilding, K. Polymer, 1997, 38 (1):43-51. [23]. Nivens, D. E., Ohman, D. E., Williamn, J., Franklin M. J., J Bacteriol. 2001;183:1047-57. [24]. Matsuhiro, B., Torres, S., Guerrero, J., Block structure in alginic acid from Lessonia vadosa (Laminariales, phaeophyta), J. Chil. Chem. Soc. 2007, 52, (1), 1-9.

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Lignosulfonate and silica as precursors of advanced composites

Abstract

Advanced silica/lignosulfonate composites were obtained using magnesium lignosulfonate and silica precipitated in a polar medium. For comparative purposes analogous synthesis was performed using commercial silica Aerosil®200. Lignosulfonates are waste products of paper industry and their application in new multifunctional materials is of great economic interest. The composites obtained were subjected to thorough characterization by determination of their physicochemical, dispersive-morphological and electrokinetic properties. Their particle size distribution was measured, SEM images were taken, FT-IR analysis and colorimetric study were made, thermal and electrokinetic stabilities and parameters of porous structure were also determined. The results can be of interest in further application studies

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Beyond Dinitrophenol Interaction with Tryptophan-Based Compounds

Abstract

The effects of 2,4-dinitrophenol (2,4-DNP) on the spectroscopic parameters (UV-Vis or FT-IR absorbance) or fluorescence emission of tryptophan and glycyl-tryptophan were studied. A quenching phenomenon of fluorescence was observed, attributed to interactions between the indole ring of the fluorophore and the aromatic ring of the quencher. The analysis of fluorescence spectra confirms that the quenching is dictated by 2,4-DNP concentration and pH. A combined mechanism of static and dynamic quenching was detected. The quenching phenomenon observed in this work could be employed to explain the mechanism of action of such compounds on large fluorescent peptides or proteins.

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Green synthesis of silver nanoparticles using tannins

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