A photocatalytic device has an ultraviolet light source and a plurality of photocatalytic structures, such as hydrated metallic catalyst surfaces. One or more catalyst substrates are adapted to support a hydroxyl radical reaction with ultraviolet light and water vapor that results in hydro peroxides and hydroxyl ions an ultraviolet light source provides ultraviolet light to the catalyst substrates. The catalyst substrates comprising a hydrated multi-metallic catalyst having two or more elements or compounds selected from the group: Titanium dioxide, Titanium Platinum, Gold, Silver, Copper, Rhodium, Ruthenium, Lanthanum, Carbon, and Fluoride. In different embodiments, various combinations of these elements or compounds may be used in the catalyst, such as a combination of five or more of the elements or compounds.