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Phone/Fax: þ36 62 544 626Multiwalled carbon nanotubes (MWCNTs) were successfully covered with metal oxides -such as TiO 2 , ZnO, Al 2 O 3 , SnO 2 , and In 2 O 3 nanoparticles -with different preparation methods under solvent conditions. The applied synthesis techniques were impregnation, a hydrothermal process and a ball-milling method. As-prepared inorganic coverage layers were characterized by TEM, HRTEM, SEM, SEM-EDX, and X-ray diffraction techniques. Results revealed that the choice of synthesis technique affects the quality and the layer structure of the deposited inorganic particles on the surface of carbon nanotubes. These materials might be suitable for nanotechnology applications.

Multi-walled carbon nanotubes (MWCNTs) were successfully coated with tin-dioxide (SnO 2 ) nanoparticles using both hydrothermal process and sol-gel technique under different solvent conditions. The obtained MWCNTs/SnO 2 nanocomposites had the mass ratio of the components 1:4, 1:8 and 1:50, respectively. The as-prepared nanocomposites were characterized in detail using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) technique. On the base of these materials gas-sensor structures are developed. The high sensitivity to methanol and ethanol vapour as well as i-butane gas at 200 o C operation temperature have been revealed for the functionalized with Ru nanocomposite thick-film sensor structures having the ratio of the components 1:8 and 1:50. The structures with 1:4 ratio of the components are characterized by the best selectivity towards influence of methanol and ethanol vapor.

Ball milling method was used to fabricate successfully tin dioxide (SnO 2 /multi-walled carbon nanotubes nanocomposite materials using SnCl 2 × 2H 2 O as precursor together with soda and salt as admixture. The as-prepared materials were characterized by transmission electron microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, Raman microscopy, and X-ray diffraction techniques. Observations revealed that applying both soda and salt are advantageous for increasing dispersity of tin dioxide nanoparticles on the surface of carbon nanotubes. These multi-walled carbon nanotube-based composites are promising candidates as thick film gas sensors or catalysts. Results indicate that SnO 2 /MWCNT composites can be achieved under solvent free dry conditions, too.

Two different preparation methods were developed to cover successfully multi-walled carbon nanotubes (MWCNT) with tin-dioxide (SnO2) nanoparticles using SnCl2 2H2O as precursor under different solvent conditions. The applied mass ratios of the components were 1:4, 1:8, 1:16, 1:32 and 1:64, respectively. As-prepared tin-dioxide coverages were characterized by TEM, SEM, SEM-EDX, Raman microscopy, BET and X-ray diffraction techniques. Photocatalytic efficiencies of selected composites were investigated in a self-made photoreactor, equipped with UV-A fluorescence lamps. Photocatalytic degradation of phenol solution was followed by using HPLC. Observations revealed that using hydrothermal method we can easily control the layer of SnO2 nanoparticles on the surface of MWCNTs. Using various solvents SnO2 nanoparticles with different morphologies formed. The nanocomposites have low photocatalytic efficiencies under conditions used generally (when >300 nm).