Huge, single-crystal nonlinear optic materials have been utilized for shortening the wavelength of high-power coherent light. If fine nonlinear optic powders can shorten wavelength of low-power incoherent visible light, they could be used in combination with fine visible-light phosphor powders to establish a dispersed ultraviolet-light source, which is considered effective for photocatalytic reactions. This proposition was indirectly verified by the enhanced decomposition rate of Orange II in water by a photocatalytic powder of TiO(2) combined with nonlinear optic powder of reagent-grade LiNbO(3). With the dispersed ultraviolet-light source generated from powders of visible-light phosphor and LiNbO(3) from a single-crystal, the photocatalytic water decontamination rate of water was enhanced approximately 5-fold compared to the case of photocatalytic powder of TiO(2) alone.