Decomposition of indoor ammonia with TiO2-coated cotton fabrics

The use of antifreeze based on urea or ammonia compounds have result in the increasing indoor air pollution owing to emission of ammonia from indoor concrete wall. In order to control indoor ammonia, aqueous dispersion of nano-TiO2 was prepared and coated on cotton fabric using pad-dry-cure process. Then TiO2-coated cotton fabrics was characterized by XRD and SEM. The decomposition of ammonia by UV/TiO2 process with TiO2-coated cotton fabric was studied under various experimental conditions. A design equation of surface catalytic kinetics was developed for describing the decomposition of ammonia in air stream. The results indicated that increasing dosage of aqueous nano-TiO2 dispersion improved the ammonia decomposition. Ammonia was effectively removed by decreasing initial ammonia concentration. When relatively humidity level was increased to 45%, the decomposition of ammonia was remarkably enhanced, and could be inhibited by excessive moisture.