Search

Indium oxide (In2O3) nanoparticles were synthesized via a facile rapid sonochemical method. Detailed spectroscopic techniques were used to investigate optical, structural and chemical properties of the synthesized In2O3 nanoparticles. The structural analysis shows that In2O3 nanoparticles have cubic structure and are polycrystalline in nature. The morphology of the In2O3 nanoparticles examined by field emission scanning electron microscopy revealed spherical and uniformly distributed particles. Bruno emit Teller surface analyzer demonstrated that the surface areas of In2O3 nanoparticles is 45 m2/g and also confirmed that the synthesized nanoparticles are mesoporous. Raman spectra also revealed that the synthesized nanoparticles have cubic structure. In–O band stretching of the synthesized In2O3 nanoparticles was confirmed using Fourier Transform Infrared Spectroscopy. Photoluminescence spectra of the In2O3 nanoparticles showed broad and intense UV emission peak at 358 nm. Moreover, the synthesized In2O3 nanoparticles showed good sensitivity and fast response toward the hydrogen gas at lower temperature. [ABSTRACT FROM AUTHOR]

The NiWO4 nanoparticles are synthesized by the facile sonochemical method and characterized using various analytical techniques. The thermal stability and the crystallization temperature of the as-prepared NiWO4 were revealed using thermogravimetric and differential thermal analysis (TG/DTA). Phase purity and crystallinity of wolframite type monoclinic structure of NiWO4 nanoparticles were corroborated using the X-ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) employed to understand the bending and stretching vibrations of the M–O bonds and the surface functional groups present in NiWO4. The average particle size of 25 nm with nearly spherical morphology of the NiWO4 nanoparticles was inferred using both scanning electron microscopic (SEM) and transmission electron microscopic (TEM) techniques. A comparative impedance spectral analysis was carried out at both room (300 K) and high temperature (973 K) to analyze the temperature-dependent conductance behaviour of NiWO4 nanoparticles. The negative temperature coefficient of resistance (NTCR) behaviour of NiWO4 nanoparticles was revealed through the decreasing resistance with increasing temperature and obtained the d.c. conductivity of 7.493 × 10−8 S cm−1 at 973 K. The hopping conduction mechanism and thermally activated mobility of charge carriers were observed in the present study. Further, the dielectric study infers the contributions of grain boundaries and grains at low and high frequencies, respectively. Finally, the room temperature paramagnetic behaviour of the NiWO4 is corroborated through vibrating sample magnetometer (VSM) analysis. [ABSTRACT FROM AUTHOR]

This work reports on sonochemical synthesis of carbon paste electrodes modified with magnetic Fe3O4/graphene nanocomposites as a label-free electrochemical biosensor for prostate-specific antigen detection. To optimize their properties as a biosensor, the compositions of both Fe3O4 and graphene were varied. The as-synthesized nanocomposites possess good crystallinity and purity with Fe3O4 nanoparticles attached onto the graphene surface. From voltammetry measurements, the modified electrode shows an increase of reduction peaks as compared to the bare electrode which promisingly led to a more sensitive biosensing detection. The modified electrode was then used for biomarker detection through the immobilization of the anti-prostate-specific antigen (anti-PSA) antibodies onto it. The results showed that the electrochemical signal increased linearly against PSA concentration, from 1 to 150 ng/mL, with a detection limit of 0.38 ng/mL. Having all these characteristics, the Fe3O4/graphene nanocomposites offer a promising path towards the development of highly sensitive prostate biosensors, especially for cancer detection. [ABSTRACT FROM AUTHOR]

Luminescent materials with LED applications can have your emission color controlled by rare earth doping. In this work, Sm3+- and Tb3+-codoped CaWO4 nanoparticles were obtained by a one-step sonochemical method. The nanoparticles were characterized by X-ray diffractogram (XRD), Raman scattering (RS) spectroscopy, The Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and visible ultraviolet spectroscopy (UV–Vis). The photoluminescent measurements were taken at room and lower temperatures for analysis of doping in emission color. The diffractograms indicate the single-phase CaWO4 with the scheelite structure and it was observed a reduction in the crystallite size as the doping. SEM and TEM images indicate the formation of nanospheres for pure and samarium-doped samples, while terbium doping results in the formation of nanorods. Room temperature photoluminescence spectra indicate a blue emission for the bare and samarium-doped CaWO4, while terbium doping emits at the green color. The codoping mixes the colors blue, green, and orange, indicating a potential material with white color emission. [ABSTRACT FROM AUTHOR]

To develop the durability and the reversibility of SnO2-based anodic materials for lithium-ion batteries, a binary composite of SnO2–CuO nanoparticles is obtained by effective ultrasonication method. Well-dispersed and high surface area particles are obtained by ultrasonication method. SnO2–CuO nanocomposite is also analysed for nitrite sensing and photocatalytic dye degradation applications. Synthesised composite is well characterised for the confirmation of elemental presence, crystallinity, surface area, topography and elemental composition. SnO2–CuO anode exhibits high initial discharge capacity of 1365 mA h g−1 and maintains 252 mA h g−1 at 100th cycle for C/10 rate. Stability of multistep electrochemical reversible reactions is confirmed by CV curves during the lithiation/de-lithiation process and also it retains 90 mA h g−1 capacity at higher 2C rate. This study is the first one to report that SnO2–CuO modified glassy carbon electrode for the sensing of 1 mM nitrite. It has proved the sensing activity with a detection limit of 0.82 μM. SnO2–CuO nanocomposite is also capable to degrade 86% of Methylene blue (MB) dye in 150 min under UV light interactions. Enhancement in the results attributed the synergistic effects of well-dispersed and nanoscaled composite particles. [ABSTRACT FROM AUTHOR]

Synthesis of Sr2FexMo2−xO6 (x = 0.8 to 1.5 with a step increment of 0.1) (SFMO) double perovskite oxides were done by sonochemical method at relatively low preparation temperature (950 °C). Purity and existence of all elements (Sr, Fe, Mo, and O) in SFMO compound have been analyzed by energy dispersive X-ray spectroscopy (EDS). Lattice parameters and unit cell volume were studied by X-ray powder diffraction (XRD). The structural transition from tetragonal to cubic occurs around composition x = 1.1 has been noticed from XRD data. Scanning electron microscopy (SEM) confirmed grain sizes of SFMO series, which are found to be in the range of 75-185 nm. Perovskite formation has been confirmed by Fourier transform infrared spectroscopy (FTIR) spectrum analysis. Investigations of Magnetic properties have been carried out using Vibrating Sample Magnetometer (VSM) at applied magnetic field from − 20 to + 20 kOe. Saturation magnetization is found to increase from x = 0.8 to 1 and then decreases from x = 1 to 1.5, the behavior is correlated with degree of Fe/Mo ordering. [ABSTRACT FROM AUTHOR]

DyO/CuO nanocomposites were synthesized by rapid and fast microwave method in polyol solvent. Effect of time and power of microwave irradiation and type of solvent on size and morphology were investigated. Synthesized DyO/CuO is characterized with X-ray diffraction (XRD) analysis, Transmission Electron Microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and UV-Visible absorption spectroscopy. Photocatalytic properties for two color, methylene blue and rhodamin b under ultraviolet light irradiation were done and 54 and 47.7% degradation for MB and RB respectively. [ABSTRACT FROM AUTHOR]

The work focuses on the synthesis of Sm(WO) nanoparticles through a reagent-free aqueous-phase sonochemical reaction between samarium nitrate hexahydrate and NaWO.2HO solutions. The prepared Sm(WO) nano-structures were also characterized by XRD, EDS and SEM to evaluate their structures and morphology. The magnetic properties of as-prepared Sm(WO) nanoparticles were also investigated with vibrating sample magnetometer (VSM). Cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) have been used to investigate the supercapacitive property of the samarium(III) tungstate electrode. The samarium(III) tungstate electrode shows high specific capacitance of 326 F g at scan rate of 2 mV s in 2.0 M HSO electrolyte. Thus, the prepared electrode could be potential electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

In this work various morphologies of Al(OH), AlO and TiO nanostructures were synthesized via sonochemical reaction at room temperature. The effect of different parameters such as power, time and surfactants on the morphology of the nanostructures was investigated. Al(OH) was calcinated to AlO nanoparticles and its photocatalytic property at presence of TiO nanoparticles in degradation of three different dyes was investigated. Nanostructures were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. For preparation of nanocomposite, aluminum hydroxide was added to polyvinyl alcohol and its thermal stability was studied by thermo-gravimetric analysis. [ABSTRACT FROM AUTHOR]

As a 2D material, few to monolayer WS have seen much research interest due to its strong excitonic effects, which will affect the optical and optoelectronic properties. In this study, we report synthesis of highly stable few-to-monolayer quantum dots of tungsten disulfide (WS) and its analysis. A facile method in which salts such as sodium hydroxid, sodium chloride, ammonium hydroxide and lithium hydroxide assisted sonochemical exfoliation of bulk WS powder has been employed in N-Methyl-2-pyrrolidone for 2 h. Resultant WS quantum dot nanosheets were characterized by the XRD, DLS, TEM, HRTEM, Raman and UV-Visible Spectroscopy to amass structural, morphological and optical properties. Salts promoted the exfoliation processes and the prepared few-to-monolayer WS quantum dot have a lateral size of 3 ± 0.5 nm and better yield in comparison to WS quantum dots in N-Methyl-2-pyrrolidone. Further the Raman and UV-Vis. analysis reiterate the successful exfoliation mechanism which consumes less time and the WS quantum dots show blue shift with an excitonic band gap of 2.7 eV. [ABSTRACT FROM AUTHOR]

In this experimental work, different morphologies of CuGaS/CuS nanostructures were synthesized via a simple ultrasonic method. The effect of different parameters was investigated on the product size and morphology, such as copper source, sulfur source, ultrasonic power and time, solvent and the reaction vessel. It was found the mentioned parameters have significant effects on the product size and morphology. The obtained products were characterized by X-ray diffraction pattern to study the product structure and scanning electron microscopy was used to study the products morphologies. [ABSTRACT FROM AUTHOR]

A controlled synthesis of CuO nanostructures with various morphologies were successfully achieved by presence/absence of low frequency (42 kHz) ultrasound with two different methods. The size, shape and morphology of the CuO nanostructures were tailored by altering the ultrasound, mode of addition and solvent medium. The crystalline structure and molecular vibrational modes of the prepared nanostructures were analysed through X-ray diffraction and FTIR measurement, respectively which confirmed that the nanostructures were phase pure high-quality CuO with monoclinic crystal structure. The morphological evaluation and elemental composition analysis were done using TEM and EDS attached with SEM, respectively. Furthermore, we demonstrated that the prepared CuO nanostructures could be served as an effective photocatalyst towards the degradation of methyl orange (MO) under visible light irradiation. Among the various nanostructures, the spherical shape CuO nanostructures were found to have the better catalytic activities towards MO dye degradation. The catalytic degradation performance of MO in the presence of CuO nanostructures showed the following order: spherical < nanorod < layered oval < nanoleaf < triangular < shuttles structures. The influence of loading and reusability of catalyst revealed that the efficiency of visible light assisted degradation of MO was effectively enhanced and more than 95 % of degradation was achieved after 3 cycles. [ABSTRACT FROM AUTHOR]

Continuous-wave heterogeneous sonochemical method was developed to synthesize 3D assemblies composed by QDs of metastable (cubic) modification of CdSe with sphalerite structural type. 3D QD assemblies were deposited in thin film form and as bulk precipitates. Structure, surface morphology, optical absorption as well as charge carriers' and phonon confinement effects were studied in details. The average nanocrystal radius, calculated by the Scherrer and Williamson-Hall methods, diminishes from 2.7 nm for samples synthesized by conventional colloidal chemical route to 2.0 nm for samples synthesized by sonochemical route. Upon post-deposition thermal annealing this value increases to 12.0 nm. QD size decrease is followed by increase of the uni-directional lattice strain and dislocation density (as defined by Hirsch), as well as by decrease of the lattice constant value. Previous findings were justified by analysis of X-ray diffraction peaks shape, which were found to be dominated by the particle size-distribution, instead of non-uniform strain. The energy of the fundamental direct $$\Gamma_{8}^{v} \to \Gamma_{6}^{c}$$ interband electronic transition, computed from optical absorption data within parabolic approximation for the dispersion relation, shifts from 2.67 eV for sonochemically deposited samples and 2.08 eV for chemically deposited ones, to 1.77 eV upon post-deposition thermal treatment (close to the bulk value of 1.74 eV). The type of 'interband' transitions does not change upon dimensionality reduce. Enhanced band gap energy blue shift upon average QD size decrease is followed by oscillator strength increase. Such trends were rationalized in terms of 3D confinement effects on charge carriers' motion. Experimentally observed band gap energies agree very well with the predictions of the effective mass model of Brus. The next direct interband electronic transition, from the spin-orbit split component of the valence band to the conduction band, has been detected and analyzed. The 1LO bands in the Raman spectra of chemically and sonochemically deposited samples appear at 206 and 204 cm, as compared to the bulk value of 210 cm. The extent of homogeneous broadening of the corresponding band is larger in sonochemically deposited samples, indicating enhanced frequency of phonon-phonon collisions in smaller QDs. The observed frequency shifts are dominated by phonon-dispersion terms, instead of lattice contraction. [ABSTRACT FROM AUTHOR]

In this paper MnWO nanoparticles were prepared via a sonochemical method based on the reaction between manganese salt and NaWO·2HO in water. Moreover, this method is free from any surfactant and organic solvents. The structural, morphological and optical properties of as-obtained products were characterized by techniques such as XRD, EDS, SEM, and UV-Visible. The magnetic properties of as-prepared MnWO nanoparticles were also investigated with vibrating sample magnetometer (VSM). To evaluate the photocatalysts properties of nanocrystalline manganese tungstate, the photocatalytic degradation of methyl orange under ultraviolet light irradiation was carried out. The new synthetic method presented in this paper has potential applications to fabricate other metal tungstates (MWO) materials. [ABSTRACT FROM AUTHOR]

In this research, we have successfully synthesized rod-like calcium molybdate (CaMoO) nanostructure via free surfactant sonochemical route by utilizing calcium (II) nitrate and ammonium heptamolybdate as the starting materials in an aqueous solution without any surfactant. The formation of CaMoO nanostructure and their structure, shape, and elemental composition were analyzed by means of several techniques including X-ray diffraction, energy dispersive X-ray microanalysis, and scanning electron microscopy. In addition, the photocatalyst activity of as-prepared CaMoO nanostructures was evaluated by degradation of methyl orange under ultraviolet light irradiation. Based on the author's knowledge, it is the first report on photocatalyst activity of CaMoO nanostructures. The CaMoO nanostructure indicated a ferromagnetic behavior, as evidenced by vibrating sample magnetometer. [ABSTRACT FROM AUTHOR]

Mn doped ZnO nanopowder was prepared by simple sonochemical method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, optical absorption (UV-Vis), photoluminescence (PL), Electron Paramagnetic Resonance (EPR), Fourier transform infrared (FT-IR) spectroscopy and magnetization have been used to characterize the sample. XRD study revealed that Mn doped ZnO had wurtzite hexagonal structure. Composition analysis by EDX indicated the presence of small amounts of manganese. Crystal field (Dq) and interelectronic repulsion (B, C) parameters are evaluated from optical absorption. Spin-Hamiltonian and bonding parameters are evaluated from the EPR study. Optical and EPR confirms that the Mn entered into ZnO lattice as distorted octahedral site symmetry. FT-IR spectrum exhibited vibrational bands of Zn-O bonds. PL spectrum shows the emission bands in UV and visible region. Magnetization loop was measured and clearly shows typical ferromagnetic saturation behavior. The results suggest oxygen vacancies, especially singly ionized oxygen vacancies, play a crucial role in mediating ferromagnetism in the Mn doped ZnO system. [ABSTRACT FROM AUTHOR]

ZnO hollow spheres and porous nanosheets were prepared by sonochemical deposition approach and hydrothermal method, respectively. Their photodegradation efficiencies for rhodamine B dye aqueous solutions under UV light irradiation were investigated in detail. Compared with ZnO porous nanosheets, the ZnO hollow spheres exhibited a relatively higher photocatalytic activity. Both absorption and photoluminescence results testified that the synergistic effects of absorption capacity and intrinsic defects finally determined the photocatalytic activity of ZnO hollow spheres. [ABSTRACT FROM AUTHOR]

In this work, FeO/ZnO nanocomposite was synthesized via a surfactant-free sonochemical method in aqueous solution. The effect of sonication time and power on the morphology and particle size of the magnetic seeds were investigated. The prepared product were characterized by X-ray diffraction pattern, scanning electron microscope, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. Alternating gradient force magnetometer showed superparamagnetic behaviour of FeO nanoparticles as well as nanocomposites containing 10 % ZnO. The photocatalytic behaviour of FeO-ZnO nanocomposites was evaluated using the degradation of eight organic dyes under ultraviolet light irradiation. The results show that FeO-ZnO nanocomposites have applicable magnetic and photocatalytic performance. [ABSTRACT FROM AUTHOR]

Bismuth selenide, BiSe, nanoparticles were synthesized by a new precursor complex, [bis(salicylate)bismuth(II)]; [Bi(Hsal)], via a sonochemical method in an aqueous solution. The average diameter of the BiSe nanoparticles was 25 nm. The efficiency of the BiSe nanoparticles as a photocatalyst for the decolorization of rhodamine-B and methylene blue using ultraviolet light irradiation has been evaluated. Furthermore, a preliminary study on the possibility of developing a solar cell having the FTO/TiO/BiSe/Pt-FTO structure was also investigated to produce an inexpensive solar cell by BiSe nanoparticles. Products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence, and EDX analysis. [ABSTRACT FROM AUTHOR]

Micro and nanostructures with well-defined shape have attracted great interest due to their novel properties and diverging applications. Herein the one step simple sonochemical method for the synthesis of carambola fruit shaped and spindle shaped semiconducting copper oxide nanostructures are described. The pH concentration and the reaction time have been varied in order to find the optimized condition in which spindle shaped and carambola fruit shaped CuO nanoparticles are obtained. Also the effect of pH and reaction time on the properties of CuO nanostructures have been investigated and reported. The possible growth mechanism for the carambola fruit shaped structures has also been discussed. The prepared samples have been characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and UV-visible spectrophotometry. [ABSTRACT FROM AUTHOR]