This application claims priority to the Taiwanese Patent Application No. 107104648 filed on Feb. 9, 2018, and which is herein incorporated by reference in its entirety.
The present disclosure relates to a photocatalyst composition, and more particularly to a photocatalyst composition used in an air filter.
Various air pollution sources that permeate in our daily lives can be divided into outdoor exhaust gases from industrial sources, transportation, volatile organic compounds, toxic gases from household furniture, or construction materials such as indoor wood floors and brick wall paints with free formaldehyde possibly, which can be discomforting during a long-term exposure or contact and even give rise to various symptoms including pricking, drying, allergy and inflammation or increase the risk of cancer. Currently, the indoor air quality has been improved mostly by installation of air cleaners.
The existing air cleaners mostly use motor to import, for example, foul air, bacteria, smell of smoke and stale odor, and then use the combination of ultraviolet light and photocatalyst (TiO2) to achieve the effect of air purification.
However, it is known that particle sizes of the photocatalyst in the existing air cleaners range between 20˜250 nm. The specific surface area of these photocatalyst particles is large and thus the effect of air purification is limited.
Improving the above deficiency is the technical problem to be solved by the present inventor.
It is therefore an object of this disclosure to provide, a photocatalyst composition.
The photocatalyst composition of the present invention comprises titanium dioxide, graphene and photoconductive materials, wherein the photoconductive materials can be silicon dioxide, quartz, glass, photoconductive plastics or photoconductive minerals. The weight percentages of titanium dioxide, graphene and photoconductive materials in the photocatalyst composition are 60˜70%, 15˜20% and 15˜20%, respectively.
Further, the invention provides an air filtration structure made of the photocatalyst composition and a substrate, wherein the photocatalyst composition is deposited on the substrate surface via the process of sintering, coating or the combination of the two. The substrate has a reticular structure which is made of flannelette, sponges, metals, polymers, composite materials or stainless steels.
The photocatalyst composition is made of graphene as carriers and uses titanium dioxide for structural modification to maintain the particle sizes of titanium dioxide below 10 nm or preferably below 7 nm. In addition, the light refraction and reflection characteristics of the photoconductive materials will be used to irradiate more ultraviolet or blue light to titanium dioxide, so as to improve the air purification ability of the photocatalyst composition.
Referring to
The graphene of the compounds 100 forms covalent bonds that break 7E bonds in graphitic layers with strong oxidizers and Van der Waals forces are further dissociated under external forces. Then, the compounds 100 are produced when the oxidized graphene is modified with titanium dioxide. After mixing the compounds 100 and the photoconductive materials 200 according to a specific proportion, a medium (solid, liquid or colloid) of the photocatalyst composition is dispensed or distributed on the substrate 300 surface via the processes of sintering, baking and/or drying.
The photocatalyst composition and the air filtration structure of the present invention are stimulated by the photocatalytic composition through ultraviolet wavelengths of less than 400 nm, or specific ultraviolet wavelengths of 365 nm or 254 nm, or blue light. When ultraviolet or blue light is irradiated on the photocatalyst composition that is distributed on the substrate surface, electron-hole pairs are generated from the compounds featuring graphene as carriers and titanium dioxide for structural modification. The electron-hole pairs further react with oxygen and moisture in air for generation of hydroxyl radicals (OH) by which airborne organics, inorganic substances, odor, bacteria, viruses, and the like are decomposed for the effective air purification.
While the preferred embodiment of the invention has been set forth for the purpose of disclosure, it should not be the limitations of the invention, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
Number | Date | Country | Kind |
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107104648 | Feb 2018 | TW | national |