Abstract: An air purification system that comprises a substrate, and at least one layer of photocatalysts. The at least one layer of photocatalysts further comprise a plurality of metal clusters.

Abstract: The present disclosure relates to nanocrystalline titanium dioxide (TiO2) photocatalysts having nanocrystallites of less than 14 nanometers in diameter, which are substantially defect-free. The TiO2 photocatalysts form porous particles having a very large mass transfer surface area, large cylindrical pores, and low mass transfer resistance. The nanocrystalline TiO2 photocatalysts provide at least 75% of the photocatalytic activity of commercially-available TiO2 crystals having diameters greater than 20 nm. The nanocrystalline TiO2 photocatalysts may be doped with a metal, metal oxide, or non-metal dopant. A process for preparing the nanocrystalline TiO2 photocatalysts is disclosed. The present disclosure also provides methods for using nanocrystalline TiO2 photocatalysts to remove contaminants.

Abstract: A photocatalyst system for volatile organic compounds with two parts that include a photocatalyst layer on a substrate and a porous overlayer. The photocatalyst layer is reactive with volatile organic compounds when UV light is projected on it. The overlayer is situated on the photocatalyst layer. The overlayer is UV transparent and has an interconnected pore network that allows contaminated air to pass through the overlayer. The size and the shape of the interconnected pores acts to selectively exclude certain contaminants that can deactivate the photocatalyst.

Abstract: The present disclosure relates to a fluid purification device that has a deactivation resistant photocatalyst having nanocrystallites of less than 14 nanometers (nm) in diameter with at least 200 m2 surface area/cm3 of skeletal volume in cylindrical pores of 5 nm in diameter or larger, with the mode of the pore size distribution 10 nm or more.

Abstract: A system is disclosed which incorporates low pressure drop contaminant removal from gas phases or streams, which advantageously can be used to enhance efficiency, improve humidity characteristics, and reduce capital cost of air handing systems such as HVAC systems and the like. Placement of the low pressure drop contaminant removal mechanism for enhancing effectiveness of same is also disclosed.

Abstract: A photocatalytic coating oxidizes volatile organic compounds that adsorb onto the coating into water, carbon dioxide, and other substances. When photons of the ultraviolet light are absorbed by the coating, reactive hydroxyl radicals are formed. When a contaminant is adsorbed onto the coating, the hydroxyl radical oxidizes the contaminant to produce water, carbon dioxide, and other substances. A humidity sensor or a temperature sensor detects the humidity or temperature, respectively, of the air entering the air purification system. Information about the optimal microwave wavelength and intensity for various humidity and temperature levels are stored in a control of a microwave actuator. The microwave actuator determines the optimal wavelength or intensity based on the sensed humidity and temperature level and sends a signal to a magnetron to emit a microwave of the desired wavelength or intensity.

Abstract: A lamp including a reflective portion is utilized in a fluid purification system to maximize the light delivery to a photocatalytic coating that oxidizes gaseous contaminants that adsorb onto the surface to form carbon dioxide, water, and other substances. An ultraviolet light source positioned proximate to the honeycomb activates the titanium dioxide coating. In one example, the reflective portion is a reflective coating. Light directed out of the non-reflective portion of the lamp travels towards the honeycomb and absorbs onto the photocatalytic coating. Light directed towards the reflective portion on the lamp is reflected off the surface of the reflective portion and passes through the non-reflective portion of the lamp to also absorb onto the photocatalytic coating. The reflective portion reflects light towards the honeycomb that would otherwise be misdirected away from the honeycomb, increasing efficiency of the fluid purification system.

Abstract: A tungsten oxide/titanium dioxide photocatalyst coating oxidizes contaminants in the air that adsorb onto the coating into water, carbon dioxide, and other substances. The tungsten oxide forms a monolayer on the titanium dioxide. When photons of the ultraviolet light are absorbed by the tungsten oxide/titanium dioxide photocatalyst coating, an electron is promoted from the valence band to the conduction band, producing a hole in the valence band. The holes in the valence band react with water applied on the tungsten oxide/titanium dioxide photocatalyst coating, forming reactive hydroxyl radicals. When a contaminant in the air is adsorbed onto the tungsten oxide/titanium dioxide photocatalyst, the hydroxyl radical attacks the contaminant, abstracting a hydrogen atom from the contaminant. The hydroxyl radical oxidizes the contaminant, producing water, carbon dioxide, and other substances. The tungsten oxide/titanium dioxide photocatalytic coating has low sensitivity to humidity variations.

Abstract: Spherical (23) or cylindrical (27, 36) electrodeless ultraviolet lamps are used to remediate fluid, directly or by excitation of ultraviolet-activated photocatalyst surfaces, which may be on the lamps themselves, or on structures which are permeable by the fluid. The lamps may be excited in cavities (18, 19; 43) by microwave energy from a magnetron (22), or by radio frequency power (39) inductively coupled (40) to the lamps. The lamps (44) may have start-up electrodes (47).

Abstract: An air purification including a reaction zone for receiving a volume of air; and an excimer source of ultra-violet radiation adapted to expose the one to the ultra-violet radiation whereby photocatalytic oxidation of compounds in the air is accomplished.

Abstract: A tungsten oxide/titanium dioxide photocatalyst coating oxidizes contaminants in the air that adsorb onto the coating into water, carbon dioxide, and other substances. The tungsten oxide forms a monolayer on the titanium dioxide. When photons of the ultraviolet light are absorbed by the tungsten oxide/titanium dioxide photocatalyst coating, an electron is promoted from the valence band to the conduction band, producing a hole in the valence band. The holes in the valence band react with water applied on the tungsten oxide/titanium dioxide photocatalyst coating, forming reactive hydroxyl radicals. When a contaminant in the air is adsorbed onto the tungsten oxide/titanium dioxide photocatalyst, the hydroxyl radical attacks the contaminant, abstracting a hydrogen atom from the contaminant. The hydroxyl radical oxidizes the contaminant, producing water, carbon dioxide, and other substances. The tungsten oxide/titanium dioxide photocatalytic coating has low sensitivity to humidity variations.

Abstract: A photocatalytic air purifier is disclosed. The photocatalytic purifier includes filter structures coated with a catalytic material such as titanium dioxide. One or more UV lamps are interposed between the filter structures. The catalytic layer reacts with airborne VOCs and bioaerosols when activated by the UV lamps to thereby oxidize the VOCs and destroy the bioaerosols. The photocatalytic air purifier does not need to be replaced or regenerated after a period of continuous usage. The photocatalytic purifier of the present invention substantially eliminates odors, VOCs, and bioaerosols from air directed through the fan coil. The photocatalytic air purifier includes a control system that optimizes operating costs. Because of these features, service, maintenance, and filter replacement are reduced to a minimum. At the same time, the well being of persons living in the space conditioned by the photocatalytic air purifier is improved.

Abstract: Spherical (23) or cylindrical (27, 36) electrodeless ultraviolet lamps are used to remediate fluid, directly or by excitation of ultraviolet-activated photocatalyst surfaces, which may be on the lamps themselves, or on structures which are permeable by the fluid. The lamps may be excited in cavities (18, 19; 43) by microwave energy from a magnetron (22), or by radio frequency power (39) inductively coupled (40) to the lamps. The lamps (44) may have start-up electrodes (47).

Abstract: A contaminated gas that is to be cleaned, such as contaminated air, is passed through an adsorbent bed to remove gaseous contaminants. An enclosure having a fixed volume is then created around the adsorbent bed. Included within the enclosure is a photocatalytic gas purifier. The adsorbent bed is heated to release the contaminants into the fixed volume to create a high concentration of contaminants in the gas within the fixed volume. The now highly contaminated fixed volume of gas is recirculated through the heated adsorbent bed and photocatalytic gas purifier. The gas purifier oxidizes the contaminants at a high oxidation rate due to the high contaminant concentration level. The enclosure is then opened and the adsorbent bed, now regenerated and at its original temperature, is ready to again receive and clean contaminated gas.