Photocatalytically active material for air purification

Reducing particulate matter from a gaseous medium comprises applying photocatalytic material to a gaseous medium to remove fine particulates. An independent claim is included for a photocatalytic material that is activated with UV light, where the photocatalytic material includes elements such as tin, zinc, tantalum, bismuth, indium, vanadium, tungsten, antimony, germanium, gallium, thallium, titanium and oxides of tin and zinc.