Titanate based photocatalysts for climate-efficient water treatment

Abstract

The sol-gel dip-coating method is a simple method to synthesize TiO2 thin film, using titanium butoxide and hydrogen peroxide. In this study in addition to TiO2 thin film, the photocatalytic activity of its intermediate products, titanium peroxide gel and ambient dried titanium peroxide film, was also evaluated. The titanium peroxide gel was used directly after gelation, ambient dried titanium peroxide film coated on glass rings was used without thermal treatment and anatase TiO2 thin film was used after thermal treatment at 500oC. These photocatalysts were characterized by different characterization techniques and their adsorption and photocatalytic activity were evaluated by using methylene blue as a model pollutant. All three photocatalysts adsorbed the selected dye model and degraded it in the presence of sunlight but with different removal rate. It was found that the gel had the highest removal rate followed by ambient dried titanium peroxide film and TiO2 thin film. However, this sequence was vice versa in the case of photocatalyst life span when the photocatalysts were reused. The photocatalytic study showed that all three photocatalysts are very effective for 100% degradation of methylene blue within 5-60 minutes under sunlight irradiation. This can be a breakthrough of using titanate based photocatalyst for the cost-effective adsorption and photocatalytic degradation of pollutants based on the climate and availability of sunlight. The energy cost analysis was performed for the catalyst based on electrical power consumption. The calculated power cost for synthesizing TiO2 thin film was approximately 0.9 $/kWh. However, the energy required for the synthesis of two other catalysts was zero, means there is no money needed to be spent on electricity.