Kalayanee Kooptarnond

Photocatalytic Activity against Penicillium Expansum of Ag-Doped TiO2/SnO2/SiO2

The effect of 0.1-1 mol%Ag doping on crystallite size, morphology, photocatalytic and fungal growth suppression activities of TiO2/SnO2/SiO2 nano-composite powders were investigated. The powder was synthesized by sol-gel method and studied for physicochemical properties by XRD, spectrometric techniques, FTIR, SEM, EDX and BET. The anatase structure was formed after calcination at 500oC. Photocatalytic activities towards Penicillium expansum growth suppression correlated to the amount of sliver doped in TiO2/SnO2/SiO2 nano-composite powder under ultraviolet radiation. Ag 1.0mol% doped in TiO2/SiO2/SnO2 composite has a significant effect on antifungal behaviour. It could completely kill Penicillium expansum within one day of photacatalytic treatment under UV irradiation.

Photochromic and Self-Cleaning Properties of TiO2-AgCl/Cu2+ Thin Films

TiO2-AgCl/Cu2+ thin films containing 0 to 1%Cu2+ coated on glass slides were prepared by sol gel-dip coating method. The prepared films were synthesized at the temperature range of 100-500 °C. The microstructure and properties of synthesized TiO2-AgCl/Cu2+ thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (DRS). Finally, the hydrophilic property was evaluated by means of contact angle of water droplet on the films. The results show that both calcinations temperature and Cu2+-doping have an effect on anatase and AgCl phase formation, crystallite sizes and phase content of the films. It was found that TiO2-AgCl/1%Cu2+ thin films calcined at 500 °C exhibit the highest photochromic (darken reaction) and self–cleaning effects (small contact angle) under UV irradiation.

Photoactivity and Hydrophilicity of B and Ni Co-Doped TiO2 Films

The effect of Ni doping in Ni and B co-doped TiO2 composite films on photocatalytic reaction and hydrophilic property were investigated. The TiO2 composite films were prepared by sol-gel and coated on glass substrates by dipping methods. These composite thin films were calcined at the temperatures of 400°C for 1 h. Phase formation of TiO2 was characterized by XRD. Morphology of TiO2 composite films were observed by using atomic force microscopy (AFM). The chemical composition and purity of the prepared films were analyzed by EDS, FTIR and FT-Raman spectrometers. The photoactivity of synthesized films was performed by means of degradation of methylene blue dye solution under UV and visible light irradiation. The hydrophilic property was measured in terms of a contact angle of water droplet on the films with and without the activation of UV irradiation. It was found that Ni doping seems to affect on TiO2 phase, crystallinity of the anatase phase, crystallite size of the composite films and band gap energy of the catalysts, resulting in their photocatalytic reaction and hydrophilic property. The crystallinity of anatase increased with an increase in Ni content varied from 0-3 mol% but decreased with an increase in Ni content above 3 mol%. It was found that 3 mol% Ni/B/TiO2 film, having highest crystallinity and smallest crystallite size shows the highest of photocatalytic reaction while 2 mol% Ni/B/TiO2 film provides the most hydrophilic effect. Only anatase phase was found at the calcination temperature of 400°C. The smooth film surfaces exhibits a high hydrophilic property. Super-hydrophilicity (contact angle equal to zero) of all B and Ni co-doped TiO2 films was found at UV irradiation for 25 minutes.

The Effect of Lithium Molybdate in Tungsten Trioxide Electrochromic Film

Lithium molybdate doped tungsten trioxide electrochromic films were prepared from tungsten trioxide precursor and lithium molybdate powder by sol-gel and dip coating methods on fluorine doped tin oxide glass. The films, which synthesized were flat and amorphous structure, which confirmed by x-ray diffraction patterns. From UV-vis transmittance spectra within the wavelength from 400 to 800 nm. and cyclic voltammogram at the applying a potential of 1.0 V (bleached state) to -1.0 V (colored state) in sulfuric acid 0.5 M solution. The doping lithium molybdate 10 mol% films showed good result in terms of transmittance modulation, high diffusion coefficient and optimal surface area. Therefore, doping lithium molybdate 10 mol% has better outcome when compared to undoped lithium molybdate.

Influence of N-Doped TiO2 Nanocomposite Film on Hydrophilic Property of Rubber Dipping Former Surface

The objective of this study is to explore a method to improve hydrophilicity of the surface of formers that could be more easily dipped to produce high quality dipped rubber products. Photocatalytic TiO2 composite films were prepared by sol-gel method. Glass formers were coated with nitrogen doped TiO2 nanocomposite film by dipping method and annealed at 600°C for 1 h. Phase formation of TiO2 was characterized by XRD. Morphology of the TiO2 films was observed by using atomic force microscopy (AFM). Optical absorption of the films and degradation concentration of methylene blue had been measured employing UV-Vis spectrophotometer. The hydrophilicity of the thin films was determined in terms of the contact angles of water and NR rubber latex droplets on the coated TiO2 composite films under visible light irradiation. It was found from the experimental study that the TiO2 nano-composite film can improve wet-ability of the coated former surfaces.

Influence of Ni/B/N/TiO2 Nanocomposite Film on Hydrophilic Property of Rubber Dipping Former Surface

The objective of this study is to explore a method to improve hydrophilicity of the surface of formers that could be more easily dipped to produce high quality dipped rubber products. Photocatalytic TiO2 composite films were prepared by sol-gel method. Glass formers were coated with the Ni/B/N/TiO2 nanocomposite film by dipping method and annealed at 400°C for 1 h. Phase formation of TiO2 was characterized by XRD. Morphology of the TiO2 films was observed by using atomic force microscopy (AFM). Optical absorption of the films and degradation concentration of methylene blue had been measured employing UV-Vis spectrophotometer. The hydrophilicity of the thin films was determined in terms of the contact angles of water and NR rubber latex droplets on the coated TiO2 composite films under visible light irradiation. It was found from the experimentally study that the Ni/B/N/TiO2 nanocomposite film can improve wet-ability of the coated former surfaces.

Photocatalytic and Self-Cleaning Properties of TiO2-Cu Thin Films on Glass Substrate

TiO2-Cu thin films containing 0 to 1%Cu coated on glass slides were prepared by sol gel-dip coating method. The prepared thin films were synthesized at the temperature of 400 ◦C for 2 h with a heating rate of 10◦C/min. The microstructures of synthesized TiO2-Cu thin films were characterized by XRD, FT-IR and SEM. The photocatalytic activities of TiO-2Cu thin films were tested using methylene blue (MB) solution under UV irradiation. Finally, the self-cleaning property was evaluated by means of contact angle of water droplet on the films. The results show all samples have the thickness in range of 1 um and surfaces are dense with a large surface area. It can be noted that TiO2-1.0Cu thin films were found to give the highest photocatalytic efficiency and exhibited self-cleaning effect (small contact angle, 17°) under UV irradiation.

Light Absorption and Structural Properties of TiO2-AgCl Thin Films Doped with Cu by Sol-Gel Process

TiO2-AgCl thin films doped with Cu were prepared by sol-gel and coated on glass slide by dip coating process. The prepared thin films were synthesized at the temperature of 400 ◦C for 2 h with a heating rate of 10◦C/min. The microstructures of synthesized thin films were characterized by XRD, AFM and SEM. Finally, the light absorption property was evaluated by UV-vis diffuse reflectance spectroscopy. The results show all samples have the thickness in range of 200-250 nm and surfaces are dense with a large surface area. It was found that Cu doping has an effect on light absorption and structure properties of the synthesized thin films. It can be noted that TiO2-AgCl-5Cu thin films showed the highest light absorption (2.50%) under UV irradiation.