a photocatalyst apparatus includes a substrate ; a plurality of photocatalytic fibers , each of the photocatalytic fibers having a core or a sheath covering the core and a plurality of photocatalytic particles dispersed therein ; and wherein the photocatalytic fibers are disposed on / in the substrate . another photocatalyst apparatus includes a substrate having a substantially transparent member and a plurality of light diffusing particles dispersed therein ; and a plurality of photocatalytic fibers disposed on / in the substrate , each of the photocatalytic fibers containing a photocatalyst disposed therein / thereon . the photocatalyst apparatus may be applicable to a dental cleaner or toothbrush . a cleaner for cleaning floors , carpets and / or walls , the cleaner includes : a cleaning head including a plurality of brushes containing a photocatalyst disposed hereon / therein ; and at least one light source in communication with the photocatalyst . the cleaner may be applicable to a vacuum cleaner .