Abstract: A photocatalytic reactor housing having a longitudinal axis allowing a fluid to flow through; a frame holding a light source and blades substantially encompassing the light source around the longitudinal axis; each blade having an interior surface facing the light source and an exterior surface opposite the interior surface; at least a portion of the surface of a plurality of the blades having a coating of material with photocatalytic oxidative properties; and the interior surface of the blade configured to redirect some amount of the light emitted onto another portion of substrate of an adjacent blade. In one embodiment the blades are tilted in the radial direction along at least a portion of the blades. In one embodiment the interior surface is configured to reflect some of the light emitted by the light source on to at least a portion of the exterior surface of an adjacent blade.