Low-temperature Solution-based Method Research Articles

Experimental Validation of TiO2 Shielded ZnO Nanorods Synthesized via Low-Temperature Solution-Based Method for Sewage System [Gas (CO and CH4) and Acceleration Sensing

Experimental Validation of TiO2 Shielded ZnO Nanorods Synthesized via Low-Temperature Solution-Based Method for Sewage System [Gas (CO and CH4) and Acceleration Sensing

Khaki-coloured niobium oxide nanochains with enhanced lithium storage performances

Khaki-coloured niobium oxides (H-Nb2O5) nanochains were synthesised via a facile low temperature solution-based method combined with hydrogenation treatment process. The nano-sized chain-like architectures facilitate the fast lithium ion diffusions. Meanwhile, the hydrogen reduction process can effectively endow Nb2O5 with partial Nb4+ species and/or oxygen vacancies, resulting in a large enhancement of its intrinsic electronic conductivity. When evaluated for lithium storage capacity, the H-Nb2O5 showed twice the rate capability at 20 C compared to that of the pristine Nb2O5 nanochains due to the combination of the reduced path and Nb4+ doping induced high electronic conductivity. This facile hydrogenation method is promising for designing high performance carbon-free electrode materials for lithium ion batteries.

Khaki-coloured niobium oxide nanochains with enhanced lithium storage performances

Khaki-coloured niobium oxides (H-Nb2O5) nanochains were synthesised via a facile low temperature solution-based method combined with hydrogenation treatment process. The nano-sized chain-like architectures facilitate the fast lithium ion diffusions. Meanwhile, the hydrogen reduction process can effectively endow Nb2O5 with partial Nb4+ species and/or oxygen vacancies, resulting in a large enhancement of its intrinsic electronic conductivity. When evaluated for lithium storage capacity, the H-Nb2O5 showed twice the rate capability at 20 C compared to that of the pristine Nb2O5 nanochains due to the combination of the reduced path and Nb4+ doping induced high electronic conductivity. This facile hydrogenation method is promising for designing high performance carbon-free electrode materials for lithium ion batteries.

Получение гибридных нанокомпозитов на основе наноразмерной целлюлозы и магнитных наночастиц с фотокаталитическими свойствами

A low-temperature solution-based method for the production of hybrid organic-inorganic nanocomposite films based on nanoscale cellulose and magnetic iron oxide nanoparticles (CNC/Fe3O4) was developed. The obtained nanomaterials were investigated by scanning electron microscopy (SEM), dynamic light scattering (DLS), energy dispersive spectroscopy analysis (EDS) and X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), and FT-IR spectroscopy. The formation of CNC/Fe3O4 nanocomposite was confirmed by the XRD analysis. According to SEM images, Fe3O4 nanoparticles are uniformly distributed on the surface of nanocellulose. The obtained nanocomposite material exhibits photocatalytic activity under visible light and UV irradiation in the rhodamine B degradation reaction. Thus, the developed biocompatible and environmentally friendly hybrid nanomaterials have great prospects of practical application in the field of biomedicine and photocatalysis.

Ultrasonic-Assisted Wet Chemistry Synthesis of Ultrafine SnO2 Nanoparticles for the Electron-Transport Layer in Perovskite Solar Cells.

SnO2 was recently employed as an efficient electron-transport layer (ETL) in perovskite solar cells (PSCs) and high power conversion efficiencies (PCEs) have been reported. However, it is still challenging to fabricate SnO2 thin films through facile solution-based synthesis at low temperature (<150 °C) to be compatible with the large scale module fabrication, especially for flexible devices. Here, we report a low temperature solution-based method for preparation of SnO2 nanoparticles. Ultrasonic-assisted wet chemistry synthesis of ultrafine SnO2 nanocrystals with particle size ranging from 2 to 5 nm was achieved by employing a SnCl4 ⋅5 H2 O solution in a mixed ethanol-water solution and with no annealing step. The crystallinity and microstructure of the SnO2 nanoparticles were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), as well as selected area electron diffraction (SAED) analysis. The added water in ethanol and increased pH values were demonstrated as two key factors to successful fabrication of highly crystallized samples with high reproducability. An efficiency of 16.56 % was achieved for PSCs based on SnO2 nanoparticles synthesized by ultrasonic-assisted wet chemistry.

Low-temperature fabrication of brown TiO2 with enhanced photocatalytic activities under visible light.

Here we report a facile one-step low-temperature solution-based method to treat native TiO2 with NaH. The NaH treatment effectively induces the Ti(iii) species and oxygen vacancies into the TiO2 host lattice, and enables the absorption edge of TiO2 to be conveniently adjusted from the UV region to the red end of the visible spectrum.

Optical and magnetic properties of (Er, F) co-doped SnO$_{2}$ nanocrystals

Uniformly (Er, F) co-doped SnO2 nanocrystals, obtained by a low-temperature solution-based method, were characterized by a variety of analytical techniques. The structure, morphology, and ratio of the elements were conrmed by PXRD, SEM, and TEM analysis, respectively. From XPS analysis, atomic concentrations of Sn, O, and F were quantied. Interparticle pore size increased signicantly (with a mean pore diameter of 25.82 nm) in the co- doped sample. Higher in-plane oxygen vacancies and bands due to multiphonon scattering were observed in the Raman spectrum of the sample. The defect traps in the sample were experimentally determined using TL spectroscopy. A broad intense glow curve at 485 K and a weak emission at 600 K in the TL spectrum were quenched on exposure to UV radiation. A large blue shift of the exciton absorption (due to the Moss{Burstein eect) and sharp bands due to intraconguration al f f transitions were observed for (Er, F) co-doped SnO2 with an estimated band gap of 4.18 eV. From the photoluminescence spectral studies, 3 types of emission centers at 471 nm, 546 nm, and 627 nm were detected. Co-doping stabilized ferromagnetism in SnO2 at room temperature.

Porous wide band gap BiNbO4 ceramic nanopowder synthesised by low temperature solution-based method for gas sensing applications

In this study, we report the gas sensing behavior of BiNbO4 nanopowder prepared by a low temperature simple solution-based method.

One-pot synthesis of magnetic γ-Fe2O3 nanoparticles in ethanol-water mixed solvent

Maghemite (γ-Fe2O3) nanoparticles were synthesized via a low-temperature solution-based method using ferric chloride hexahydrate and ferrous chloride tetrahydrate as precursors in the mixed solvent of ethanol and water. X-ray diffraction, energydispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy revealed that the obtained product was pure γ-Fe2O3. Transmission electron microscopy showed the morphology of the nanoparticles to be approximately spherical in shape with an average diameter of 11 nm. Magnetization measurements indicated the dry powders exhibit ferromagnetic behavior with a maximum saturation magnetization of 41.1 emu/g at room temperature.

A low-temperature solution route to hollow NH4VO3 microspheres with controllable shells

NH4VO3 hollow microspheres with controllable shells have been synthesised by the interaction between AgNO3 and NH4VO3 via a facile one-step low-temperature solution-based method. The diameters and surface roughness of NH4VO3 hollow spheres can be readily controlled by altering the molar ratios of NH4VO3 to AgNO3. When the molar ratios of NH4VO3 to AgNO3 increase from 6 : 1 to 8 : 1, the diameters of NH4VO3 hollow spheres increase from 500–600 to 800–900 nm and the building blocks of the shells are assembled by nanoparticles and nanorods. The introduction of AgNO3 and H2O2 plays an important role in the formation of NH4VO3 hollow microspheres.

Cathodoluminescence of Single Disk-Like ZnO Prepared by Low Temperature Solution-Based Method

Single crystalline ZnO disk-like structure with good luminescent properties was obtained by a low temperature solution based method. Micro-emulsion was employed to assist the shape control. The product has a perfect hexagonal shape with flat bottom and up surfaces, and has a wide size distribution, the size ranges from nano to micro-scale. Electron diffraction (ED) pattern coupled with transmission electron microscopy (TEM) indicate that the single disk was single-crystalline. In cathodoluminescence (CL) studies at room temperature for wavelengths between 350 and 675 nm, we have observed a single exciton peak around 390 nm without any deep-level emission. The monochromatic CL mapping in the ultra-violet (UV) region has such properties as: the intensity is concentrated along the boundary of the cavity; the emission is predominantly at the corner. [DOI: 10.1380/ejssnt.2009.354]

Low-temperature synthesis and structural characterization of single-crystalline tungsten oxide nanorods

In the current research, we have successfully fabricated single-crystalline cubic WO 3 nanorods by a low-temperature solution-based method. The detailed microstructures of the as-synthesized products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray fluorescence (EDX), and Raman spectroscopy. The rod-like nanomaterials may be helpful in studies of the specific nanostructure growth mechanisms and find applications in numerous fields.

Iron Oxide Nanopropellers Prepared by a Low-Temperature Solution Approach

The alpha-Fe(2)O(3) (hematite) nanopropellers were synthesized via a low-temperature solution-based method using FeCl(2) as a precursor in the presence of urea and glycine hydrochloride. The formation of alpha-Fe(2)O(3) nanopropellers is strongly depended on the addition of glycine hydrochloride, which serves as a pH modulator and affects the oxidation rate of Fe(2+). The structural evolution of the propeller-structured hematite was found to follow dissolution and recrystallization processes. For the structural conformation, each nanopropeller presents a hexagonal central column closed by six equivalent surfaces of {(-)1100} and the six arrays of the nanopropeller structure are a result of growth along +/- [(-)1100], +/- [(-)1010], and +/-[0(-)110]. Preliminary results show that the magnetic maghemite (gamma-Fe(2)O(3)) nanopropellers could also be prepared by a reduction and reoxidation process from the alpha-Fe(2)O(3) (hematite) nanopropeller precursors.

Low Temperature Synthesis, Characterization and Evaluation of Limn2O4 for Lithium Ion Batteries

Lithium manganese oxide, LiMn2O4, was prepared by a low temperature solution-based method and the physical and electrochemical properties compared with commercially available LiMn2O4. Samples of the two powders were analyzed by X-ray diffraction in order to identify the constituent phases. Particle size distribution was determined using a laser analyzer and the morphology examined by high resolution scanning electron microscopy. Electrochemical cells were assembled in a controlled atmosphere chamber and charge-discharge cycling was performed using a computer-controlled galvanostat-potentiostat. Over a duration of 21 cycles, the discharge behaviour of the synthesized material was superior to that of the commercial material. This improvement in performance was attributed to the sub-micron crystallite size of the synthesized powder.On a préparé de l’oxyde de manganèse et lithium, LiMn2O4, au moyen d’une méthode à basse température, à base de solution, et l’on a comparé les propriétés physiques et chimiques avec du LiMn2O4 disponible commercialement. On a analysé des échantillons des deux poudres par diffraction des rayons X afin d’identifier les phases constituantes. On a déterminé la répartition granulométrique en utilisant un analyseur au laser et l’on a examiné la morphologie par microscopie électronique à balayage à haute résolution. On a assemblé des cellules électrochimiques dans une chambre à atmosphère contrôlée et l’on a effectué des cycles de charge–décharge en utilisant un galvanostat–potentiostat commandé par ordinateur. Sur une durée de 21 cycles, le comportement de décharge du matériel synthétisé était supérieur à celui du matériel commercial. Cette amélioration du rendement était attribuée à la taille submicronique du cristallite de la poudre synthétisée.