Co2+ substituted La2CuO4/LaCoO3 perovskite nanocomposites: synthesis, properties and heterogeneous catalytic performance

Cobalt substituted La₂CuO₄/LaCoO₃ perovskite nanocomposites were prepared using a microwave combustion method.

Effect of growth time on Ti-doped ZnO nanorods prepared by low-temperature chemical bath deposition

Ti-doped ZnO nanorod arrays were grown onto Si substrate using chemical bath deposition (CBD) method at 93 °C. To investigate the effect of time deposition on the morphological, and structural properties, four Ti-doped ZnO samples were prepared at various deposition periods of time (2, 3.5, 5, and 6.5 h). FESEM images displayed high-quality and uniform nanorods with a mean length strongly dependent upon deposition time; i.e. it increases for prolonged growth time. Additionally, EFTEM images reveal a strong erosion on the lateral side for the sample prepared for 6.5 h as compared to 5 h. This might be attributed to the dissolution reaction of ZnO with for prolonged growth time. XRD analysis confirms the formation of a hexagonal wurtzite-type structure for all samples with a preferred growth orientation along the c-axis direction. The (100) peak intensity was enhanced and then quenched, which might be the result of an erosion on the lateral side of nanorods as seen in EFTEM. This study confirms the important role of growth time on the morphological features of Ti-doped ZnO nanorods prepared using CBD.

Structural and magnetic properties and DFT analysis of ZnO:(Al,Er) nanoparticles

The structural and magnetic properties of the investigated ZnO : (Al, Er) nanoparticle powders synthesized by hydrothermal method.

Influence of Fe-Doping on the Structural, Morphological, Optical, Magnetic and Antibacterial Effect of ZnO Nanostructures

Pure and Fe-doped ZnO nanostructures with different weight ratios (0.5, 1.0, 1.5, and 2.0 at wt% of Fe) were successfully synthesized by a facile microwave combustion method using urea as a fuel. The detailed structural characterization was performed by means of X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). XRD patterns refined by the Rietveld method indicated that Fe-doped ZnO have a single pure phase with wurtzite structure, suggesting that Fe ions are successfully incorporated into ZnO crystal lattice by occupying Zn ionic sites. Interestingly, the morphology was found to change substantially from grains to nanoflakes and then into nanorods with the variation of Fe-content. The optical band gap estimated using DRS was found to be red-shifted from 3.220 eV for the pure ZnO nanostructures, then decreases up to 3.200 eV with increasing Fe-content. Magnetic studies showed that Fe-doped ZnO nanostructures exhibit room temperature ferromagnetism (RTFM) and the saturation magnetization attained a maximum value of 8.154 x 10(-3) emu/g for the highest Fe-content. The antibacterial activity of pure and Fe-doped ZnO nanostructures against a Gram-positive bacteria and Gram-negative bacteria was investigated. Pure ZnO and Fe-doped ZnO exhibited antibacterial activity, but it was considerably more effective in the 1.5 wt% Fe-doped ZnO nanostructures.

Microwave Based Synthesis; Structural, Optical and Magnetic Measurements of Co²⁺ Doped MnFe₂O4

CO²⁺ doped manganese ferrite (Mn₁₋xCoxFe₂O₄, x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) samples were synthesized by a microwave combustion method. Nitrates of the constituent elements and urea were respectively used as the oxidizer and fuel to drive the reaction. On an average a yield of 80% were obtained for all the compositions. Light-absorbing properties from UV-Vis diffuse reflection spectrum were studied and the results infer that the band gap energy (Eg) of the pure MnFe2O4 is 1.76 eV and with increase in C02+ ion concentration, it increases to 2.25 eV. The phase purity and crystal lattice symmetry were estimated from X-ray diffraction (XRD) and was identified as the spinel cubic crystal structure. The lattice parameter is found to decrease with an increase in Co content. The crystallite size was in the range of 19-25 nm. The purity and the composition of the elements were further confirmed by energy dispersive X-ray (EDX) results. Microstructural features obtained by scanning electron microscope (SEM) demonstrate that the nanocrystals were formed with a decrease in average grain size with C02+ content. Room temperature magnetic measurement for stoichiometric samples is discussed with the help of vibrating sample magnetometer (VSM). The saturation magnetization (M), remanant magnetization (Mr) and coercivity (H.) are measured from the respective hysteresis plots.

Structural, Optical and Magnetic Properties of Ni-Zn Ferrite Nanoparticles Prepared by a Microwave Assisted Combustion Method

Ni-doped ZnFe₂O₄(Ni(x)Zn₁₋xFe₂O₄; x = 0.0 to 0.5) nanoparticles were synthesized by a simple microwave combustion method. The X-ray diffraction confirms the presence of cubic spinel ZnFe₂O₄for all compositions. The lattice parameter decreases with an increase in Ni content resulting in the reduction of lattice strain. High resolution scanning electron microscope images revealed that the as-prepared samples are crystalline with particle size distribution in 40-50 nm range. Optical properties were determined by UV-Visible diffuse reflectance and photoluminescence spectroscopy respectively. The saturation magnetization (Ms) shows the super paramagnetic nature of the sample for x = 0.0-0.2, whereas for x = 0.3-0.5, it shows ferromagnetic nature. The Ms value is 1.638 emu/g for pure ZnFe₂O₄ sample and it increases with increase in Ni content.

A Simple Combustion Synthesis and Optical Studies of Magnetic Zn1-xNi(x)Fe2O4 Nanostructures for Photoelectrochemical Applications

Ni-doped ZnFe2O4 (Ni(X)Zn1-x,Fe2O4; x = 0.0 to 0.5) nanoparticles were synthesized by simple microwave combustion method. The X-ray diffraction (XRD) confirms that all compositions crystallize with cubic spinel ZnFe2O4. The lattice parameter decreases with increase in Ni content resulting in the reduction of lattice strain. High resolution scanning electron microscope (HR-SEM) and transmission electron microscope (HR-TEM) images revealed that the as-prepared samples are crystalline with particle size distribution in 42-50 nm range. Optical properties were determined by UV-Visible diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy respectively. The saturation magnetization (Ms) shows the superparamagnetic nature of the sample for x = 0.0-0.2, whereas for x = 0.3-0.5, it shows ferromagnetic nature. The Ms value is 1.638 emu/g for pure ZnFe2O4 sample and it increases with increase in Ni content. Photoelectrochemical (PEC) measurements showed a significant increase of photocurrent density with increase in the Ni-dopant, and 0.5% Ni-doped ZnFe2O4 sample was found to show the better photoresponse than the other doping concentrations.

One-Pot Low Temperature Synthesis and Characterization Studies of Nanocrystalline α-Fe2O3 Based Dye Sensitized Solar Cells

Dye-sensitized solar cell (DSSC) based α-Fe2O3 nanostructures with two different morphologies, such as nanorods (FeONRs) and nanoparticles (FeONPs), were synthesized by one-pot low temperature method. The crystal structure and phase purity of the as-prepared samples were characterized by X-ray powder diffraction (XRD) and further determined by Rietveld refinements XRD analysis. The average crystallite size was calculated using Debye Sherrer formula, and it shows the range of 9.43-26.56 nm. The morphologies of the products were studied by high resolution scanning electron microscopy (HR-SEM) and it was confirmed by high resolution transmission electron microscopy (HR-TEM). The formation of pure α-Fe2O3 samples was further confirmed by energy dispersive X-ray (EDX) analysis. The optical properties and the band gap energy (E(g)) were measured by UV-Visible diffuse reflectance spectra (DRS) and photoluminescence (PL) spectra. The band gap energy was measured using Kubelka-Munk method, and the values are decreased from 2.36 eV to 2.21 eV as the temperature increased from 300 to 400 degrees C with increasing the crystallite size. Magnetic hysteresis (M-H) loop revealed that the as-prepared α-Fe2O3 samples displayed ferromagnetic behavior. FeONRs sample shows higher saturation magnetization (M(s)) value (40.21 emu/g) than FeONPs sample (23.06 emu/g). The dye-sensitized solar cell based on the optimized FeONRs array reaches a conversion efficiency of 0.43%, which is higher than that obtained from FeONPs (0.29%) under the light radiation of 1000 W/m2.

Synthesis of α-Fe2O3 Sphere/Rod-Like Nanostructure via Simple Surfactant-Free Precipitation Route: Optical Properties and Formation Mechanism

Sphere/rod-like α-Fe2O3 nanostructure were successfully synthesized by simple surfactant-free precipitation route. The as-prepared samples were characterized by X-ray powder diffraction (XRD) to determine the phase purity and the crystal structure. The lattice parameter and crystallite size of the samples have been calculated from the Rietveld analysis. The crystallite size has been compared by Scherrer's formula and Rietveld method and both method showed increase of the grain size with the increase of the calcined temperature. The crystallite size was in the range of 5-30 nm. The high resolution scanning electron microscopy (HR-SEM) analysis of the samples shows that the morphology of the nanostructures changed from nanospheres into nanorods and it was confirmed by high resolution transmission electron microscopy (HR-TEM). Energy dispersive X-ray (EDX) analysis reveals the presence of O and Fe elements only. The optical properties of the as-prepared nanostructures were determined by photoluminescence (PL) spectra. The band gap energy was investigated by UV-Visible diffuse reflectance spectra (DRS) and calculated by means of the Kubelka-Munk method. The band gap values are decreased from 2.26 eV to 2.17 eV as the temperature increased from 300 degrees C to 400 degrees C with increasing the crystallite size. A Vibrating Sample Magnetometer (VSM) was used to study the magnetic properties of iron oxide (α-Fe2O3) nanostructures. Magnetic hysteresis (M-H) loops revealed that the as-prepared α-Fe2O3 samples displayed ferromagnetic behavior.

First principles and DFT supported investigations on vibrational spectra and electronic structure of 2-((phenylamino)methyl)isoindoline-1,3-dione--an antioxidant active Mannich base

The 2-((phenylamino)methyl)isoindoline-1,3-dione (PID) is a synthesized Mannich base which has significant antioxidant activity and biological importance. Quantum mechanical calculations on energy, geometry and vibrational wavenumber of PID were computed using ab initio HF and density functional theory (DFT/B3LYP) methods with 6-31+G/6-311++G(d,p) basis sets. Optimized geometrical parameters obtained by HF and DFT calculations were indicatively agreement with experimental crystal geometry. The experimental FT-Raman and FT-IR spectra of PID has been recorded and analyzed by comparing with simulated spectra. The (1)H and (13)C NMR spectra of title molecule records the chemical shift resulted from shielding and deshielding effects. Natural bond orbital (NBO) analysis has been carried out to calculate various intramolecular interactions that are accountable for the stabilization of this Mannich base. The predicted HOMO-LUMO gap offers interesting information on intramolecular charge transfer and reactivity of the molecular system. Molecular electrostatic potential (MEP) imprint visualize the reactive sites in PID, which is also supported by Mulliken, ESP, Hirshfeld and NBO charges. Thermodynamic properties of PID at various temperatures have been calculated at B3LYP/6-311++G(d,p) in gas phase and the correlations between standard entropies (S), internal energy (E or U) and standard heat capacity (C) with different temperatures.

Spectroscopic analysis, structural, microstructural, optical and electrical properties of Zn-doped In2O3 thin films

In this work, highly transparent conducting un-doped and Zn-doped In2O3 thin films were prepared onto glass substrate using spray pyrolysis method. Structural, morphological, optical and electrical properties were characterized by using XRD, FT-IR, FT-Raman, SEM, AFM, UV-visible, PL and Hall Effect measurement techniques. X-ray diffraction analysis showed that the deposited films were polycrystalline with cubic structure having (222) as preferred orientation. SEM and AFM analyses showed smooth surfaces but the surface roughness of the films increased due to Zn doping. The average optical transmittance of the films was above 94% in the visible range. The optical band gap decreased from 3.62 to 3.28 eV with increasing Zn concentration. The photoluminescence spectra displayed violet-blue emission peaks at around 418-440 nm for all films. The electrical parameters like the resistivity, mobility and carrier concentration were found as 6.4×10(-4) Ω cm, 168 cm(2)/Vs and 9.4×10(20) cm(-3), respectively for In2O3:Zn film deposited at 9 at.%. The present results showed that the obtained thin films could be used as an optoelectronic material.

Optical and magnetic properties of Co-doped CuO flower/plates/particles-like nanostructures

In this study, pure and Co-doped CuO nanostructures (0.5, 1.0, 1.5, and 2.0 at wt% of Co) were synthesized by microwave combustion method. The prepared samples were characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). Powder X-ray diffraction patterns refined by the Rietveld method indicated the formation of single-phase monoclinic structure. The surface morphology and elemental analysis of Co-doped CuO nanostructures were studied by using HR-SEM and EDX. Interestingly, the morphology was found to change considerably from nanoflowers to nanoplates then to nanoparticles with the variation of Co concentration. The optical band gap calculated using DRS was found to be 2.1 eV for pure CuO and increases up to 3.4 eV with increasing cobalt content. Photoluminescence measurements also confirm these results. The magnetic measurements indicated that the obtained nanostructures were ferromagnetic at room temperature with an optimum value of saturation magnetization at 1.0 wt.% of Co-doped CuO, i.e., 970 micro emu/g.

Preparation and characterizations of SnO2 nanopowder and spectroscopic (FT-IR, FT-Raman, UV-Visible and NMR) analysis using HF and DFT calculations

In this work, pure and singe phase SnO2 Nano powder is successfully prepared by simple sol-gel combustion route. The photo luminescence and XRD measurements are made and compared the geometrical parameters with calculated values. The FT-IR and FT-Raman spectra are recorded and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (LSDA, B3LYP and B3PW91) theory in bulk phase of SnO2 and are compared with its Nano phase. The vibrational frequency pattern in nano phase gets realigned and the frequencies are shifted up to higher region of spectra when compared with bulk phase. The NMR and UV-Visible spectra are simulated and analyzed. Transmittance studies showed that the HOMO-LUMO band gap (Kubo gap) is reduced from 3.47 eV to 3.04 eV while it is heated up to 800°C. The Photoluminescence spectra of SnO2 powder showed a peak shift towards lower energy side with the change of Kubo gap from 3.73 eV to 3.229 eV for as-prepared and heated up to 800°C.

Insilico molecular modeling, docking and spectroscopic [FT-IR/FT-Raman/UV/NMR] analysis of Chlorfenson using computational calculations

In the present work, the recorded FT-IR/FT-Raman spectra of the Chlorfenson (4-Chorophenyl-4-chlorobenzenesulfonate) are analysed. The observed vibrational frequencies are assigned and the computational calculations are carried out by DFT (LSDA, B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are investigated with the UV/NMR data. The fluctuation of structure of Chlorobenzenesulfonate due to the substitution of C6H4Cl is investigated. The vibrational sequence pattern of the molecule related to the substitutions is intensely analysed. Moreover, (13)C NMR and (1)H NMR chemical shifts are calculated by using the gage independent atomic orbital (GIAO) technique with HF/B3LYP/B3PW91 methods on same basis set. A study on the electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The calculated energy of Kubo gap (HOMO and LUMO) ensures that the charge transfer occurs within the molecule. Besides frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP) is executed. NLO properties and Mulliken charges of the Chlorfenson is also calculated and interpreted. Biological properties like the target receptor identification, and Identification of interacting residues, of this compound is identified and analysed by using SWISSMODEL, Castp, Hex and Pdb Sum. By using these properties, the mechanism of action of this compound on ATP Synthase of Tetranychus urticae is found and it is very much useful to develop efficient pesticides having less toxic to the environment.

Spectroscopic study and optical and electrical properties of Ti-doped ZnO thin films by spray pyrolysis

Zinc oxide films were doped with different concentrations of Ti on glass substrates at 400°C by spray pyrolysis technique. The films exhibited single phase ZnO for low concentrations of Ti. Wurtzite ZnO peaks were observed at higher doping concentration with decreased crystallinity. Crystallite size, strain and dislocation density were evaluated from the X-ray diffraction data. Surface morphology of the films indicated that a remarkable decrease in grain size with increasing of Ti concentration. The band gap of the films was found to be increased from 3.20 eV to 3.32 eV as the concentration of Ti doping increases. The resistivity of the films decreased from 9×10(5) Ω cm to 9×10(4) Ω cm with the increase of Ti doping concentration. Both Raman spectroscopy and room temperature photoluminescence exhibited characteristic peaks that confirmed the formation of ZnO phase.

Metal organic chemical vapour deposition (MOCVD) of bone mineral like carbonated hydroxyapatite coatingsElectronic supplementary information (ESI) available: experimental data. See http://www.rsc.org/suppdata/cc/b3/b312855p/

For the first time, the MOCVD technique has been used to deposit carbonated hydroxyapatite onto Ti6AL4V substrates using volatile monomeric (liquid) complexes [Ca(beta-diketonate)(2)(L)] and P(OEt)(3).