Tungsten oxide/titanium dioxide photocatalyst for improving indoor air quality

An air purification system comprising:

• a substrate;
• a metal oxide/titanium dioxide photocatalytic coating including monolayer tungsten oxide on titanium dioxide, and said photocatalytic coating is applied on said substrate, wherein said monolayer of tungsten oxide partially covers said titanium dioxide;
• and
• a light source to activate said tungsten oxide/titanium dioxide photocatalytic coating, and said tungsten oxide/titanium dioxide photocatalytic coating oxidizes contaminants in an air flow that are adsorbed onto said tungsten oxide/titanium dioxide photocatalytic coating when activated by said light source.

An air purification system comprising:

• a container having an inlet and an outlet;
• a porous substrate inside said container;
• a device for drawing a fluid into said container through said inlet, flowing said fluid through said porous substrate, and expelling said fluid out of said container through said outlet;
• a tungsten oxide/titanium dioxide photocatalytic coating including a monolayer of tungsten oxide on titanium dioxide, the monolayer of tungsten oxide having a thickness no greater than one molecular unit, and said tungsten oxide/titanium dioxide photocatalytic coating is applied on said porous substrate;
• and
• an ultraviolet light source to activate said photocatalytic coating, and photons from said ultraviolet light source are absorbed by said tungsten oxide/titanium dioxide photocatalytic coating to form a reactive hydroxyl radical, and said reactive hydroxyl radical oxidizes contaminants in said fluid that are adsorbed onto said tungsten oxide/titanium dioxide photocatalytic coating when activated by said light ultraviolet light source to water and carbon dioxide in the presence of water and oxygen.

A method of purifying air comprising the steps of;

• applying a monolayer of tungsten oxide on titanium dioxide to produce a photocatalytic coating on a substrate, the monolayer of tungsten oxide having a thickness no greater than one molecular unit;
• activating said tungsten oxide/titanium dioxide photocatalytic coating;
• forming a reactive hydroxyl radical;
• adsorbing contaminants in an air flow onto said tungsten oxide/titanium dioxide photocatalytic coating;
• and
• oxidizing said contaminants with said hydroxyl radical.