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In the present investigation, we report on Iron oxide (α-Fe2O3) nanoparticles synthesized by simple hydrothermal method with different reaction times as 6 h (H1) and 8 h (H2) for supercapacitor application. The significance of varying the reaction time on structural, morphological, and vibrational properties of α-Fe2O3 was explored. XRD, FTIR, and Raman study affirmed that the products consist of only the rhombohedral phase of α-Fe2O3 nanoparticles. SEM image infers that with a change in reaction time the surface morphology of α-Fe2O3 changed from spherical to octahedra. The size of nanoparticles reduced with reaction time. XPS spectra again confirmed the growth of α-Fe2O3 nanoparticles. The electrochemical characteristics of the fabricated H2 electrode exhibited excellent performance in a 2 M KOH electrolyte solution. The specific capacitance (Cs) achieved from CV and GCD curves were 299.4 F g−1, and 351.3 F g−1. The Rct acquired via electrochemical impedance (EIS) reduced from 11.2 to 9.18 Ω demonstrating the rise in the conductivity of the prepared electrodes. Remarkable capacitance retention of 92% was accomplished, even after 1000 cycles, thus making α-Fe2O3 nanoparticles a most promising electrode for the fabrication of energy storage devices. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized Mn-doped SnO2@ZnO nanocomposite for photo degradation of Methylene blue and Rhodamine B dyes upon visible light irradiation. The crystal structure, functional group, optical absorption, defect related emission, morphology, purity and binding energy state of synthesized samples were identified by using various analytical tools. The crystal structure revealed the rutile tetragonal, hexagonal wurtzite for SnO2 and ZnO samples and the average crystal sizes were found in the range of 23.3 nm to 16.7 nm for the synthesized samples. The optical absorption peaks were shifted to higher wavelength side and optical band gap values were found between 3.52 eV and 2.77 eV which confirm the formation of hetero-junction of SnO2@ZnO composites. The field emission scanning electron spectroscopy (FESEM) revealed the spherical grain morphology for pure and composite samples. The energy dispersive spectra (EDS) and element mapping confirms the purity of the synthesized samples. The X-ray photoelectron spectroscopy (XPS) revealed that the composition and energy state of Mn4+, Sn4+ and Zn2+ for composite samples. The photocatalytic degradation results clearly indicate that the Mn-doped SnO2@ZnO nanocomposite has higher degradation efficiency of 98% and 92% for the Methylene blue and Rhodamine B dyes, respectively and is higher than the other synthesized samples. The present study reveals a low cost and highly efficient photo-catalyst which works up on visible light irradiation for the purification of waste water from industries. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) nanocubes were fruitfully synthesized via facile solvothermal route. The crystalline nature and structural confirmation of the synthesized nanocubes was revealed by XRD and Raman studies. The oxygen defects and luminescent abilities were explored by PL studies. The FTIR metal-oxygen vibrations present in Cu2O nanocubes was observed at 510 cm−1. The typical nanocube morphology and the decrease in particle size with NaOH concentration increase was revealed by SEM images. The particle sizes of the best performed nanocubes (2 µm) have been tested for antimicrobial properties. The particle size effect on improved diamagnetic behavior of 5 × 10−3 emu/g was reported for 6 µm scale range. The enhanced antibacterial properties against Gram-positive (Bacillus thuringiensis) and Gram-negative (Pseudomonas aeruginosa) bacteria were reported. [ABSTRACT FROM AUTHOR]

The manuscript presents structural, optical and magnetic properties of CuFeO nanoparticles obtained employing a simple co-precipitation method in aqueous solution. Influence of ferric chloride concentration on the structural, optical and magnetic properties of CuFeO nanoparticles was investigated. XRD results clearly revealed the spinel tetragonal copper ferrite structures. The observed characteristic Raman E, F and A phonon mode of vibrations revealed the tetragonal copper ferrite structures. The observed PL results explored inverse spinel copper ferrite emission peaks in the range of visible region. IR result revealed the metal oxygen intrinsic vibrations of octahedral and tetrahedral sites in the spinel copper ferrite structure. SEM analysis clearly revealed the spherical shape morphology particles sizes are in the nano scale range. VSM studies clearly revealed that copper ferrite exhibit weak ferromagnetic behaviour. It was found that the ferric chloride concentration added to copper chloride precursor in the ratio of 1:1, 1:2 and 1:3 during the synthesis process played a significant role in structural and magnetic properties of the obtained product. [ABSTRACT FROM AUTHOR]

Co doped FeO thin films were deposited by using Iron (II) Sulfate heptahydrate (FeSO·7HO) and cobalt sulfate heptahydrate (CoSO·7HO) as precursors using SILAR method. Structural analysis using XRD reveals a decrease in crystallite size with doping is due to the accommodation of dopant atoms into the host matrix and excess atoms occupy the interstitials. In accordance with this dislocation density is found to be increased with increasing doping concentration. XRD results also reveal that Co is substituted into the Fe lattice, since both Fe and Co have same ionic radii and hence the structural properties of the thin film are intact with minor internal modifications. Raman analysis was used to find the vibrations and the polymorphs of iron oxide and the doping. The morphology of the samples was studied using FESEM. Absorption and transmission spectra of the deposited thin films were analyzed using UV-Vis spectrometer, the absorption value decreases with increase in wavelength whereas, transmission value increases with increase in wavelength. The defects in the deposited films were studied using PL studies. Magnetic properties were analyzed using VSM and it confirms the exchange interactions between the dopant and host atoms. [ABSTRACT FROM AUTHOR]

Triglycine sulphophosphate (TGSP), chloroacetamide (AC) and 4-dimethylaminobenzaldehyde (DB) doped TGSP crystals were successfully grown from their respective aqueous solutions by slow cooling method. X-ray powder diffraction patterns were collected for pure, AC and DB doped TGSP crystals in order to determine their lattice parameter values. Fourier Transform Infra-Red (FTIR) spectroscopic analysis was carried out to confirm the molecular vibrations of TGSP and the presence of AC and DB in TGSP qualitatively. From the UV-Vis spectroscopic analysis, the absorption range was observed for the grown crystals. From the microhardness test, the Vickers's hardness of the AC and DB doped TGSP crystals measured on (001) face was found to be higher than that of pure TGSP crystals. The dielectric studies showed the variation of dielectric constant as a function of frequency at room temperature. The thermal behavior of the pure and doped TGSP samples was studied from their thermogravimetric and differential thermal curves. [ABSTRACT FROM AUTHOR]

Nanocrystalline magnetite thin films were deposited on glass substrates using simplified SILAR method. Variations in structural, optical and magnetic properties were studied with respect to annealing temperature. XRD results reveals the nanocrystalline film formation of cubic structured magnetite (FeO), whose crystallite size increases with annealing. SEM images shows the spherical morphological agglomeration which varies with annealing. Transmission in UV-Vis radiation increases with annealing of films and maximum % transmission was observed for near IR range. VSM result reveals the magnetically soft nature of the deposited films with increasing M, H values on annealing. [ABSTRACT FROM AUTHOR]

Thin films of tungsten oxide (WO) nanostructures were grown on indium tin oxide coated glass substrates by thermal evaporation technique under oxygen and argon (O/Ar) mixed gas atmosphere. The films were characterized by X-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy to study the structural and morphological properties of the grown films. Three different shapes of nanostructures (one dimensional nanorods, two dimensional nanosheets and three dimensional nanosized orthorhombic structures) were formed due to the variations of growth conditions such as substrate temperature and oxygen/argon flow rate. In particular, the flow rate of oxygen plays an important role in controlling the nucleation and growth of WO nanostructures. The ethanol gas sensing properties of the films were investigated under different concentrations (10-50 ppm) at room temperature, which reveals that the sensitivity of the sensor was greatly enhanced with the increasing gas concentration. This result indicates that the WO films are good candidate for sensing ethanol gas in low concentration at room temperature. [ABSTRACT FROM AUTHOR]