Abstract: The hydrated catalytic coating is a coating that is applied to a substrate or target structure in the path of a broad spectrum ultraviolet light in the 100 nm to 300 nm range to decompose ozone. The coating is particularly useful in conjunction with germicidal UV lamps emitting UV radiation at 185 nm and 254 nm. The coating is a combination of a hydrophilic agent and the following metals: titanium dioxide (TiO2); silver (Ag); copper (Cu); nickel (Ni); and rhodium (Rh). At least three of the five metals are present as particles in the 50-100 nm range. The nanosize particles increase the surface area of the catalyst, improving the kinetic rate of reaction and the total reduction in ozone concentration. The particular mixture of catalytic metals and absorbed water also results in reaction products that have antimicrobial effect, including hydroxyl radicals and ions, superoxides, hydro peroxides and ozonide ions.