METAL DOPED TITANIUM DIOXIDE FOR REMOVAL OF FORMALDEHYDE VAPOR

Abstract

Formaldehyde (HCHO) is one of the most popular volatile organic compounds (VOCs), which is toxic to human health. HCHO in indoor air is often of anthropogenic sources such as construction materials, home appliances, new furniture, office equipment, detergents, and refrigerants. In addition, HCHO is a product of cooking and burning incense daily in household. This work studies on the photocatalytic removal of formaldehyde in air with catalysts such as pure and metal doped titanium dioxides. Experiments to remove HCHO were carried by photolysis, adsorption and photocatalysis. The results showed that efficiency of photocatalysis was 1.6 and 3.8 times higher than those of adsorption and photolysis, respectively. The experiments were then conducted using TiO₂ (P25) modified at different temperatures, metal oxides, and metal/titanium ratios. Under test condition, the results showed that zinc doped P25 with Zn/Ti ratio of 0.5% and annealed at 500^oC had the high removal efficiency of 98%. These results imply that zinc doped TiO₂ is a promising photocatalytic material for control of HCHO in air.