An exemplary apparatus for photocatalytic reaction includes a light-permeable substrate, a photocatalytic layer, and one or more converging lenses. The light-permeable substrate includes a first surface and an opposite second surface. The photocatalytic layer is formed on the first surface of the substrate. The lenses are movably formed on the second surface of the substrate and are configured for converging light onto the photocatalytic layer. The apparatus further includes one or more optical filters. The optical filters each include at least one layer assembly. The layer assembly is formed on one of a topside and an underside of the respective lens. Alternatively, the layer assembly can be formed on one of the first and second surfaces of the substrate. The optical filters are configured for allowing light of at least one predetermined band to pass therethrough.