Development of a Photocatalytic Filter to Control Indoor Air Quality

Background The aim of this work was the development and characterization of a photocatalytic filter for the treatment of indoor air, characterized by a low pressure drop. Methods The filter (photocatalytic filter) was based on a polyester substrate additivated with active carbon (Carbotex 150-6), treated with a sol of titanium dioxide (Sol 121-AB; NextMaterials Ltd.) and illuminated with UV LEDs to induce photocatalytic activity. Results Tests showed that this filter, used in a suitable device for air circulation with a very low noise level, had the ability to block solid particulates, to photocatalytically oxidize a major fraction of volatile organic compounds (VOCs) and deactivate all of the bacteria blocked on the filter, in contrast to traditional commercial air filters on which the bacteria remain viable. Conclusions Activated charcoal filters treated with TiO ₂ and illuminated by UV LEDs were found to be extremely effective in killing bacteria and effective in decreasing VOC and total suspended particulates (TSP).