JOURNAL OF NANOSTRUCTURES
Year:2016 | Volume:6 | Issue:1|Papers Count:17

Dye-sensitized solar cells present promising low-cost alternatives to the conventional Silicon (Si) -based solar cells. The counter electrode generally consists of Pt deposited onto FTO plate. Since Pt is rare and expensive metal, nanostructured carbonaceous materials have been widely investigated as a promising alternative to replace it. Carbon nanotubes have shown significant properties such as cost-effectiveness, environmental friendliness, availability, corrosion resistance and excellent catalytic activity towards the redox species make them ideal for replacing Pt in the CEs of DSCs. The review presented below gives a succinct summary of the Carbon nanotubes materials in use as counter electrode in dye-sensitized solar cells.

In this paper, the morphology, roughness and nano structural properties of SiO2/Poly Vinyl Pyrrolidone synthesized with sol gel method, characterized by using scanning electron microscopy, atomic force microscopy and GPS132A techniques. The main material taken from oxide silicon with weight percentage of 20, 40, 60, 80 and from poly vinyl pyrrolidone with percentages of 80, 60, 40, 20 is synthesized and are called sample 1, 2, 3 and 4 respectively. The samples using lower poly vinyl pyrrolidone (PVP: SiO2; 2: 3 in Weight) can be suitable choices in producing organic field-effect transistors due to their better structuralquality, less energy loss, less roughness sample surface, higher dielectric constant (K=15.99) and better surface morphology as determined with applying DME SPM software and above techniques. This sample can be thus considered as a good element of the future organic field-effect transistors devices.

In current work, CdS/black carbon nanocomposites were successfully synthesized with the aid of chestnut and cadmium nitrate as the starting reagents. Besides, the effects of preparation parameters such as reaction time, and precursor concentration on the morphology of products and removal of heavy metals (Hg+2, Pb+2) were studied by scanning electron microscopy images and batch adsorption mode. CdS/black carbon nanocomposite introduced as new and high efficient system for removal of heavy metal ions. The as-synthesized products were characterized by powder X-ray diffraction, scanning electron microscopy, and spectra energy dispersive analysis of X-ray.

In this work, copper oxide nanoparticles have been synthesized via extractive Rosmarinus Officinalis leaves by simple and economic co-precipitation method at ambient conditions which it has used (CH3COO) 2Cu+H2O individually as Cu sources. It was found that uniform copper oxide nanoparticles have been successfully produced at various temperature, namely 400, 600, and 8000C. Powder X-ray Diffraction analysis confirmed copper oxide nanoparticles are in monoclinic phase, which the average crystalline size estimated by using Williamson-Hall plot from the higher peak of the Powder X-ray Diffraction was about 20-30 nm for all samples. Field Emission Scanning Electron Microscopy images depict various morphologies can be successfully prepared via controlling calcination temperature and using appropriate green extractive. The study of FT-IR patterns of CuO nanoparticles confirm the formation of highly pure CuO nanoparticles. The prepared nanoparticles were subjected to the following characterizations such as, Xray diffraction, Field Emission Scanning Electron Microscopy, and Fourier transform infrared studies.

Dye sensitized solar cell was fabricated from a double layer photoanode. First, TiO2 nanoparticles were synthesized by hydrothermal method. These TiO2 NPs were deposited on FTO glasses by electrophoretic deposition method in applied voltage of 5 V and electrophoretic deposition time of 2.5-10 min. Then TiO2 hollow spheres were synthesized by sacrificed template method with Carbon Spheres as template anditanium (IV) isopropoxide as precursor. Then these template scarified and the hollow structures found.Since the HSs paste was prepared as same method of prepared TiO2 nano particles and this paste was deposited on last layer by Dr. Blade method. The prepared photoanodes was soaped in N-719 dye after sintering in 500 UC.The dye sensitized solar cells were fabricated with the finalized double layer photoanodes. The best photovoltaic characteristics of the optimized cell were 734 mV, 13.16 mA/cm2, 62% and 5.96% for Voc, Jsc, F.F. and efficiency respectively.

Titanium dioxide (TiO2) nanoparticles, with an average size of about 45 nm, were encapsulated by polystyrene using in situ nitroxide mediated radical polymerization in the presence of 3-aminopropyl triethoxy silane as a coupling agent and 2, 2, 6, 6-tetramethylpiperidinyl-1-oxy as a initiator.First, the initiator for nitroxide mediated radical polymerization was covalently bonded onto the surface of Titanium dioxide nanoparticles through our novel method. For this purpose, the surface of TiO2 nanoparticle was treated with 3-aminopropyl triethoxy silane, a silane coupling agent, and then these functionalized nanoparticles was reacted with ± -chloro phenyl acetyl chloride.The chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2, 2, 6, 6-tetramethyl piperidine. These modified TiO2 nanoparticles were then dispersed in styrene monomers to carry out the in situ free radical polymerization.

ZnO nanoparticles were synthesized by a microwave-assisted chemical method. ZnO nanostructures were synthesized via a fast reaction between zinc acetate and ammonia at presence citric acid and other effective agents in chemical procedure. Nanostructures were characterized by X-ray diffraction, scanning electron microscopy. Seed yield and seed quality of safflower grown under drought stress. The test includes control treatments priming with distilled water, priming with zinc sulphate in the amount of 300 mg per ml, priming with sulfate of zinc to 600 mg per liter, priming with Nano priming on the amount of 300 mg per liter, with Nano on priming rate of 600 mg per liter, priming with zinc sulphate in the amount of 300 mg/l zinc sulphate along with spraying the amount of 300 mg, zinc sulfate with priming to the amount of 600 mg/l zinc sulphate along with spraying the amount of 600 mg, priming with Nano over the amount of 300 mg per liter plus the foliar application of nano on the amount of 300 mg, priming with Nano over the amount of 600 mg per liter plus the foliar application to nano on 600 mg, zinc sulfate to foliar application with the amount of 300 mg per liter, foliar application with Nano over the amount of 300 Mg/l, respectively.

Catalytically graphitized electrospun carbon nanofibers adorned uniformly with fine nickel nanoparticles were successfully prepared. The procedure was based on the electrospinning technique and the use of nickel precursor to create both graphitized nanofibers and nickel nanoparticles under a relatively low-temperature heat treatment. The X-ray diffraction and Raman results clearly proved catalytic graphitization of polymer-based carbon fibers in the presence of nickel catalyst. Taking the results from scanning and transmission electron microscopies and X-ray diffraction into account, it was inferred that during the heat treatment, nickel atoms have diffused through the nanofibers and formed fine nickel nanoparticles on the surface of graphitized nanofibers to make a well stabilized heterogeneous nanostructure. The results from Brunauer–Emmett–Teller technique also showed a high surface area value of 140.2 m2g-1 for the obtained structure. All these attributes along with the fibrous and porous structure enable the product to serve as a potential candidate in the catalysis applications.

In order to improve UV and visible lights photocatalytic activities of the pure anatase TiO2, a novel and efficient N-doped TiO2 photocatalyst was prepared by sol-gel method. N-doped titania is prepared using triethylamine (with difference molar ratios) as the nitrogen source. The crystalline structure, morphology, particle size, absorbance and band-gap and chemical structure of N-doped TiO2 was characterized by X-ray diffraction, diffuse reflectance spectra, scanning electron microscopy, energy dispersive spectrometry and Fourier transform infrared techniques, respectively. Results indicate that the doping of N, cause absorption edge shifts to the visible light region compare to the pure TiO2, reduces average size of the TiO2 crystallites, enhances desired lattice distortion of Ti, promotes separation of photo-induced electron and hole pair, and thus improves pollutant decomposition under UV and visible lights irradiation. The photocatalytic activities of N-doped TiO2 nanoparticles were evaluated using the photodegradation of methyl orange (MO) as probe reaction under the irradiation of UV and visible light and it was observed that the N-TiO2 photocatalyst shows higher visible photocatalytic activity than the pure TiO2. The optimal N/TiO2 concentration to obtain the highest photocatalytic activity was 2: 1 of triethylamine.

In this pepper Fe2O3 nanoparticles were synthesized via a fast microwave method. Then Fe2O3-TiO2 nanocomposites were synthesized by a sonochemical-assisted method. The prepared products were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared spectroscopy. The photocatalytic behaviour of Fe2O3-TiO2 nanocomposites was evaluated using the degradation of Rhodamine B under ultra violet irradiation. The results show that nanocomposites have applicable magnetic and photocatalytic performance.

This research reports a facile ultrasonic approach for the synthesis of iron vanadate (FeVO4) nanoparticles with the aid of ammonium metavanadate (NH4VO3) and Fe (NO3) 3.9H2O as the starting reagents without adding external surfactant, capping agent or template in an aqueous solution. Furthermore, to examine the solar cell application of as-synthesized iron vanadate (FeVO4) nanoparticles, FTO/TiO2/FeVO4/Pt-FTO structure was created by deposited iron vanadate film on top of the TiO2 layer. The VSM magnetic measurement result shows that a maximum magnetization of 0.16 emu/g was obtained for FeVO4 nanoparticles after annealing at 550oC for 150 min. The as- synthesized FeVO4 ferrite powders were characterized by X-ray diffraction, scanning Electron Microscopy, spectra energy dispersive analysis of X-ray, and vibrating sample magnetometer techniques. The X-ray diffraction study showed that pure anorthic phase of FeVO4 nanoparticles have been produced after calcinations at 550°C for 150 min. Solar cell result indicates that an inexpensive solar cell could be developed by synthesis of FeVO4 nanoparticles through the ultrasonic approach.

The current study presents synthesis and characterization of high impact polystyrene - TiO2 nanoparticles mixed matrix membranes for separation of carbon dioxide from nitrogen. The solution-casting method was used for preparation of membranes. The nano mixed matrix membranes were characterized using scanning electron microscopy to ensure the suitable dispersion of nano particles in high impact polystyrene matrix. The effect of TiO2 nanoparticles loading on membrane performance was investigated. The separation performance of synthesized membranes was investigated in separation of CO2 from CO2/N2 mixture. Effect of feed pressure and TiO2 content on separation of CO2 was studied. The results revealed that increase of feed pressure decreases flux of gases through the mixed matrix membrane. The results also confirmed that the best separation performance can be obtained at TiO2 nanoparticles loading of 7 wt.%.

Nickel hydroxide nanostructures were synthesized by a hydrothermal reaction. The effect of different precursors and surfactants on the morphology of nickel hydroxide nanostructures was investigated. Nanostructures were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy.The influence of Ni (OH) 2 nanostructures on the thermal stability and flame retardancy of the poly vinyl alcohol and cellulose acetate matrix was studied using UL-94 analysis. The enhancement of thermal stability and flame retardancy of nanocomposites is due to the endothermic decomposition of Ni (OH) 2 and release of water which dilutes combustible gases.

In this work we synthesized of mesoporous silica nanoparticles and functionalized with 3-aminopropyltriethoxysilane to improve the loading and release of ibuprofen bonded to 3-aminopropyltriethoxysilane. sample were characterized by Fourier transform infrared spectroscopy, Scanning electron microscopy, X-ray diffraction, and ultraviolet-visible. the Fourier transform infrared spectroscopy result demonstrate that organic group were successfully functionalized onto mesoporous silica nanoparticles. Then, we investigate of the adsorption and release of ibuprofen as a drug delivery system in simulated body fluid. The result demonstrates that high adsorption capacity for drug with functionalized sample and slower drug release rate was achieved.

Nano structures such as nanowires, nanobeams and nanoplates have been investigated widely for their innovative properties. In this paper the buckling of nanowires surrounded in a Winkler - Pasternak elastic medium has been examined based on the nonlocal Euler-Bernoully model with considering the surface effects. In the following a parametric study that explores the influence of numerous physical and geometrical parameters on the buckling of nanowires is presented. It has been shown that by growing the ratio of surface area to bulk in nano-size structures, the effect of surface energy turn out to be important and should be taken into consideration. Moreover the results point out that surface elasticity and residual surface tension stimulus the buckling behavior of nanowires.

The biocompatible and biodegradable polymer nanofiber with high potential for anti-bacterial coating are used for: multi-functional membranes, tissue engineering, wound dressings, drug delivery, artificial organs, vascular grafts and etc. Electrospinning nanofiber made of scaffolding due to characteristics such as high surface to volume ratio, high porosity and very fine pores are used for a wide range of applications. In this study, polymer composite nanofiber Silica/chitosan/poly (ethylene oxide) /cefepime antibiotic synthesis and antibacterial properties will be discussed. The optimum conditions for preparation of electrospun nanofiber were: voltage; 21 kV, feed rate; 0.5 mL/ h, nozzle-collector distance; 10 cm, and chitosan/poly (ethylene oxide) weight ratio 90: 10 and the volume ratio of chitosan/silica is 70: 30. The antibacterial activity of composite scaffolds were tested by agar plate method by two type bacteria including Escherichia coli and Staphylococcus aureus. With the addition of the silica to chitosan, the hybrid was more biodegradable and improves the mechanical properties of biopolymer.

Recycling and reusing of catalyst is an important factor to produce capable and low cast catalysts. Silica coated magnetic nanoparticles (Fe3O4/SiO2) were synthesized via a simple sol-gel method with the aid of sonication. Fe3O4 nanoparticles. After that a layer of TiO2 was constricted by hydrolyze and condensation of Teteranormalbuthyltitanate to produce Fe3O4/SiO2/TiO2 nanocompsite. As-synthesized nanparticles were characterized with X-Ray powder Diffraction, Fourier-Transform-Infrarotspektrometer, Transition Electron Microscopy and Scanning Electron Microscopy. In this study, a new kind of Fe3O4/SiO2/TiO2 photocatalyst was prepared with the purpose of using light and inhibiting the recombination of electrons and holes. In situ treatment of Rhdamine B in water was performed using this Fe3O4/SiO2/TiO2 photocatalyst. The purpose of this research was to provide a new method and the basic data for the removal of organic pollutants in water. Fe3O4/SiO2/ TiO2 nanocomposite showed enhanced photocatalytic properties as evidenced by the enhanced photodegradation of Rhodamine B under ultra violet light irradiation.