Weerachai Sangchay

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.

Effect of calcinations temperature on microstructures, photocatalytic activity and self-cleaning property of TiO2 and SnO2/TiO2 thin films prepared by sol-gel dip coating process

The purpose of this research was to study the effect of calcinations temperature on phase transformation, crystallite size, morphology, photocatalytic activity and self-cleaning properties of TiO2 and SnO2/TiO2 thin films. The thin films were preparation by sol-gel dip coating process and calcinations at the temperature of 500 °C, 600 °C and 700 °C for 2 h with the heating rate of 10 °C/mim. The microstructures of the fabricated thin films were characterized by XRD and SEM techniques. The photocatalytic activity of the thin films was also tested via the degradation of methylene blue solution under UV irradiation. Finally, self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without UV irradiation. It was found that SnO2/TiO2 thin films calcinations at the temperature of 500 °C shows the highest of photocatalytic activity and self-cleaning properties.

Phase Transformations and Photocatalytic Activity of TiO2 Powders Preparation via Microwave-Assisted Sol-Gel Method

The purpose of this research was to study phase transformation and photocatalytic properties of TiO2 powders. TiO2 powders were prepared by microwave-assisted sol-gel method. The prepared powders were refluxed at 18 W to 450 W for 1 h and dried at 180 W for 1 h by a conventional microwave oven. The phase transformations of powders were characterized by XRD and photocatalytic activities of powders were evaluated by UV-Vis spectrophotometer. The results show all samples reveal that only the anatase phase and has the crystallite size is 13.8, 10.3 and 9.2 nm when the refluxed at 180, 300 and 450 W. It was found that TiO2 powders refluxed at 450 W were found to give the highest photocatalytic efficiency is about 90.06% under UV irradiation for 6 h.

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.

Photocatalytic Activity under UV of TiO2 Powders Compared with Commercial P25

TiO2 powders were prepared by sol-gel method. The prepared powders were synthesized at the temperature of 500 °C to 700 °C for 2 h with a heating rate of 10 °C/min. The characterizations of synthesized powders were characterized by XRD and SEM. Finally, photocatalytic activity was evaluated by UV-vis spectrophotometer compared with commercial P25. The results show all samples have the agglomeration. It was found that the effect of calcinations temperature on phase transformation, crystallite size, morphology and photocatalytic activity of the synthesized powders. It can be note that TiO2 powders show highes of photocatalytic activity more than P25 and calcined at 700 °C were found to give the highest photocatalytic efficiency (82%) under UV irradiation 6 h.

Effect of Calcinations Temperature on the Structural and Photocatalytic Activity of TiO2 Powders Prepared by Sol-Gel Method

TiO2 powders were prepared by sol-gel method. The prepared powders were synthesized at the temperature of 200 °C to 700 °C for 2 h with a heating rate of 10 °C/min. The characterizations of synthesized powders were characterized by XRD and SEM. Finally, photocatalytic activity was evaluated by UV-vis spectrophotometer. The results show all samples have the agglomeration. It was found that the effect of calcinations temperature on phase transformation, crystallite size, morphology and photocatalytic activity of the synthesized powders. It can be note that TiO2 powders calcined at 700 °C were found to give the highest photocatalytic efficiency (81.7%) under UV irradiation.