Hollow sea urchin-like α-Fe₂O₃ nanostructures has been successfully prepared by a hydrothermal method using Fe(NO₃)₃·9H₂O and Na₂SO₄ as starting materials. The structure and morphology of α-Fe₂O₃ were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM). The hollow sea urchin-like α-Fe₂O₃ nanostructures with the diameters of 2-5 μm consist of well-aligned α-Fe₂O₃ nanorods growing radically from the centers of the nanostructures. Gas sensing properties of the hollow sea urchin-like α-Fe₂O₃ nanostructures were measured to ammonia, LPG, ethanol, acetone. The experimental results showed that the α-Fe₂O₃ nanostructures are promising gas sensing material for the detection of flammable and toxic gases with good-sensing characteristics. [DOI: 10.1380/ejssnt.2011.508]

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ZnO nanostructures were prepared by hydrothermal method starting from Zn(CH₃COO)₂, citric acid and NaOH. SEM images indicated that the samples have a spherical shape consisting of small wires with a diameter of about 50 nm. It is seen that the samples have large surface areas and will be attractive for applications like catalyst, catalyst sensors and solar cells. In this report, photocatalytic capacity of ZnO nanoparticles was investigated by time-dependent absorption spectra of 10 mg/L blue methylen solution. The results show that catalysis was almost complete after 120 minutes. The effects of pH value on the morphology and photoluminescence properties of the samples have also been investigated. [DOI: 10.1380/ejssnt.2011.512]

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The colloidal ZnS:Mn nanoparticles were obtained by using thermochemical method with the reaction duration varied from 1 h to 7 h. The bandgap of the ZnS:Mn nanocrystals increases from 3.75 eV to 4.06 eV with decreasing particle size from 5.8 nm to 2.4 nm, respectively. At room temperature, the ZnS:Mn nanoparticles exhibit orange-red emission due to the ⁴T₁(⁴G) → ⁶A₁(⁶S) transition within the 3d⁵ configuration of Mn²⁺ ions inside the ZnS host. The orange-red photoluminescence can be excited at energies corresponding to the Mn²⁺ ion own excited states. The ⁶A₁(⁶S)→ ⁴E₂(⁴P); ⁶A₁(⁶S)→ ⁴T₂(⁴P); ⁶A₁(⁶S)→ ⁴E(⁴G), ⁴A₁(⁴G); ⁶A₁(⁶S)→ ⁴T₂(⁴G), and ⁶A₁(⁶S)→ ⁴T₁(⁴G) absorption transitions have been observed in the photoluminescence excitation spectra. Photocatalytic properties of the samples have been investigated via absorption spectra of methyl orange (MO) in present of ZnS:Mn nanoparticles. The photo-degradation of MO obeys the pseudo-first-order kinetics law. The reaction rate constant k for MO degradation was 0.0065 min^-1. [DOI: 10.1380/ejssnt.2011.516]

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ZnS nanoparticles were synthesized by hydrothermal and co-precipitation methods. The starting precursors were sodium thiosulfate and zinc chloride for the hydrothermal method; zinc acetate dihydrate and sodium polyphosphate for the co-precipitation method. Scanning electron microscopy (SEM) images of ZnS powder prepared by hydrothermal route show the co-existence of individual ZnS nanoparticles and microspheres formed by the nanoparticles. When acrylamide was added to the process, ZnS porous nanospheres were obtained. Structural properties of ZnS powder prepared by both methods were studied by means of X-ray diffraction (XRD) which revealed that ZnS nanoparticles has the cubic phase and the average size of ZnS nanocrystallites is in the range of 10 nm. Photoluminescence excitation (PLE) and photoluminescence (PL) spectra of ZnS powder synthesized by hydrothermal method indicated that the luminescence intensity of the ZnS nanoparticles was affected by reaction time and surfactant meanwhile a blueshift of about 8 nm compared to bulk ZnS was observed in PLE data of ZnS powder prepared by co-precipitation method, that indicates the quantum confinement effects. [DOI: 10.1380/ejssnt.2011.521]

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The ZnAl₂O₄:Co²⁺ powders with the low Co²⁺ dopant concentrations (0.5 at.%) have been synthesized by hydrothermal method using the following precursors: zinc chloride (ZnCl₂), aluminium chloride (AlCl₃·6H₂O), cobalt nitrate (Co(NO₃)₂), urea (CO(NH₂)₂), ethanol (C₂H₅OH) and sodium hydroxide (NaOH). The effect of the amounts of NaOH, CO(NH₂)₂ and thermal treatment conditions on formatting the ZnAl₂O₄ structure and their optical properties were investigated. The results showed that the structure and the size of ZnAl₂O₄ crystallites strongly depended on the amount of NaOH, CO(NH₂)₂ and thermal treatment conditions. The photoluminescence and photoluminescence excitation spectra of the samples strongly depended on the thermal treatment conditions. For the samples which did not undergo thermal treatment, their optical properties almost did not depend on the amounts of CO(NH₂)₂. For the samples undergone thermal treatment at 800 °C and 1200 °C, the photoluminescence and photoluminescence excitation spectra were totally changed. They strongly depended on the excitation wavelength and amount of urea in the initial sample synthesis process. [DOI: 10.1380/ejssnt.2011.526]

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The Al_2-xCr_xO₃ powders with dopant contents ranging from x = 0.005 to 0.35 have been prepared by sol-gel method. The powders were prepared from aluminium nitrate Al(NO₃)₃·9H₂O, chrome nitrate Cr(NO₃)₃·9H₂O, and citric acid and heat-treated at 650-1300°C for 5 h. The effect of dopant concentration and heat-treating temperature on the structural and optical properties of the synthesized samples has been studied. The results showed that the structure, the size and optical properties of Al_2-xCr_xO₃ crystallites strongly depended on the mole fraction x and heating temperature. At low heating temperatures, the samples with the low mole fraction x exhibit γ-Al₂O₃ phase and the emission spectra consist of a broad asymmetric peak with the maximum at 691 nm. With the high mole fraction x, the samples consist of α-Al₂O₃ and Cr₂O₃ phases. By increasing the mole fraction x, the emission bands are broadened and shifted towards the long-wavelength side. At high heating temperatures, all the synthesized samples are α-Al₂O₃ single phase and the emission spectra mainly consist of lines at 691.6 and 693.2 nm. [DOI: 10.1380/ejssnt.2011.531]

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Magnetic nanoparticles (NPs) with modified surface are important materials for applications in biological systems. In this paper, FePt NPs have been prepared by electrodeposition method. After annealing at 700°C for 1 h under a mixture of 5% H₂ and 95% Ar atmosphere the FePt NPs exhibit the coercivity of 11.5 kOe. The FePt NPs are then coated with a layer of silica SiO₂ by using the Stober method assisted by mechanical waves originated from a sonicator. The FePt/SiO₂ NPs were easily bound with 3-aminopropyl-triethoxy-silance to have an amino surface. Analysis of transmission electron microscope reveales the core-shell structure of the NPs. [DOI: 10.1380/ejssnt.2011.536]

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Ti-MCM-41 with various ratios Ti/Si was synthesized successfully and characterized by some measurements as XRD, DR-UV-Vis, TEM, EDAX and N₂-Adsorption. The peak in bands 230 nm in DR-UV-Vis spectroscopy showed that Ti was in tetrahedral coordination. The TEM, EDAX images indicated that the obtained materials were of ordered mesoporous structures in the samples with low ratio of Ti/Si. Moreover, increasing the thickness of material wall calculated by BJH method was due to the incorporation of titanium in the framework. The oxidation of α-pinene over Ti-MCM-41 with various ratios Ti/Si indicated that the possibility of Ti in the tetrahedral coordination gave a priority to the selectivity of α-pinene oxide. The Ti content of materials system increased, consequently the conversion of the reaction and the pinandiol product yield increased. [DOI: 10.1380/ejssnt.2011.539]

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Gold nanoparticles (GNPs) have been synthesized by a chemical reduction method using sodium borohydride and functionalized with amino groups on their surface. The GNPs were then conjugated with the anti-HER2 human antibody (trastuzumab) for detecting breast cancer cells. The specific binding of trastuzumab-conjugated GNPs onto the breast cancer cells (KPL4 line) were observed by bright-field and dark-field microscopy and were for the first time observed by scanning electron microscopy and energy dispersive X-ray scanning. [DOI: 10.1380/ejssnt.2011.544]

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Figure 4 in Ref. [1] should be corrected as shown here. This revision, however, does not affect our conclusions.

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