No abstract

Nanocomposites of titanium dioxide (TiO(2)) and multi-walled carbon nanotubes (MWNTs) were prepared and deposited by sol-gel spin coating on borosilicate substrates and sintered in air at 300 °C for 15 min. Further irradiation of the films with different CO(2) laser intensities (4.3-17 W m(-2)) was carried out in order to crystallize TiO(2) in the anatase form while preserving the MWNT's structure. The laser irradiation changed the crystal structure of the coatings and also affected the wettability and photocatalytic activity of the films. The anatase phase was only observed when a minimum laser intensity of 12.5 W m(-2) was used. The contact angle decreased with the enhancement of the laser intensity. The photocatalytic activity of the films was determined from the degradation of a stearic acid layer deposited on the films. It was observed that the addition of carbon nanotubes themselves increases the photocatalytic activity of TiO(2) films. This efficiency is even improved when high CO(2) laser intensities are used during the sintering of the coatings.

The present study focuses on the synthesis, structural and magnetic characterization of CoCuFeNi high entropy alloy particles. The hydrogen reduction assisted ultrasonic spray pyrolysis method was used to synthesize nanocrystalline quaternary CoCuFeNi particles in a single step. The effect of synthesis temperature on the structure, morphology and the size of particles was investigated. The syntheses were performed at 700 °C, 800 °C, and 900 °C with 0.1 M concentration of metal nitrate salts precursor solution. The structure and morphology of products were characterized through X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and vibrating sample magnetometer studies. Diffraction pattern based calculations revealed that crystallite sizes of CoCuFeNi particles were in the range of 15.6–26.7 nm. Scanning electron microscopy and energy dispersive spectroscopy investigations showed that particles were agglomerated from crystallites and in spherical morphology with equiatomic elemental composition. According to vibrating sample magnetometry results, soft magnetic properties were observed for CoCuFeNi particles. X-ray photoelectron spectroscopy results showed that the surface has a thin layer of copper oxide.

No abstract

Self-cleaning and anti-fogging coatings can be realized utilizing TiO 2 thin films on various substrates. Photoactive TiO 2 films exhibit strong oxidation power to breakdown organic compounds when illuminated by UV. TiO 2 thin films possess photo-induced hydrophilicity, which is required for self-cleaning properties. They give optical quality with high reflectivity when coated on glass. In the present study, commercial float glass samples were coated by using sol-gel dip-coating process. Coated glasses were heat treated at 400 o C for obtaining the desired properties. In order to monitor the photoactivity of the films, the decrease in the absorption of the aqueous solution of rhodamine B was measured after light irradiation of film surfaces as a function of time. The photoactivity of the films was measured also through the decomposition of stearic acid applied onto TiO 2 films. In this study, the effects of film thickness and mean crystallite size on the photoactivity were given and discussed.