An apparatus and method for the photocatalytic conversion of contaminants in a
fluid stream. Fluid is directed through a semitransparent packed bed or an open
cell, three dimensionally reticulated, fluid permeable, semiconductor unit. Within
the unit, a semiconductor, when exposed to a photoactivating light source, converts
the contaminants through a photocatalytic reaction. Both the substrate and the
semiconductor photocatalyst are semitransparent to the activating light to allow
penetration of light into the unit, thereby distributing the light, increasing
the active specific surface area, and improving the net conversion performance
of the unit.
