Plasma photonic techniques for disrupting contaminants in fluids

Abstract

A material composition for purifying a fluid, the composition comprising a photocatalyst and nanoparticles of a non-oxidizing metal alloy, such as plasma nanoparticles. An article for purifying a fluid includes a substrate having a first surface opposite a second surface and a coating on one of the first surface and the second surface. The coating includes a photocatalyst and plasma nanoparticles. A system for purifying a fluid, the system comprising a housing defining a space, a light source removably coupled to the housing and configured to emit radiation at a predetermined frequency, a substrate positioned proximate the light source, the substrate comprising plasma nanoparticles configured to emit radiation at a predetermined frequency, and a space defined between the light source and the substrate and configured to receive a fluid.

Description

[0001] Cross-references to Related Patent Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 442,676, filed February 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to material compositions and systems for destroying contaminants in fluids (eg, gases or liquids). Contaminants may include, but are not limited to, biological and chemical contaminants. Background Art

[0004] Air quality is often compromised by pollutants such as viruses, bacteria, and volatile organic chemicals (VOCs). Reducing airborne pollutants is beneficial to human and environmental health.

[0005] Therefore, those skilled in the art continue to conduct research and development in the field of improving air quality. Summary of the Invention

[0006] This summary is intended only to provide a brief overview of some aspects of one or more implementations of the present disclosure. Other areas of application of the present disclosure will become apparent from the detailed description provided below. This summary is not an extensive overview, nor is it intended to identify the key or crucial elements of this teaching, nor is it intended to describe the scope of the present disclosure. Instead, its purpose is merely to present one or more concepts in a simplified form as a preface to the detailed description below.

[0007] The applicants have discovered a composition of matter for use in purifying fluids.

[0008] In one example, the material composition includes a photocatalyst and nanoparticles of a non-oxidizing metal alloy.

[0009] In one example, the non-oxidizing metal alloy comprises a metal and an electron scavenger. In one example, the nanoparticles are plasmonic nanoparticles. In one example, the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm. In one example, the nanoparticles of the non-oxidizing metal alloy have an average particle size ranging from about 30 nm to about 70 nm.

[0010] In one example, the material composition is configured to emit radiation at a frequency having a wavelength ranging from about 350 nm to about 420 nm.

[0011] In one embodiment, the material composition includes a surfactant. In one embodiment, the surfactant is an alcohol.

[0012] Also disclosed are articles for purifying fluids.

[0013] In one example, an article includes a substrate having a first surface opposite a second surface, and a coating on one of the first surface and the second surface. The coating includes a photocatalyst and plasmonic nanoparticles.

[0014] In one example, the substrate comprises a fiber material, a fabric, a metal, a cellulose material, a ceramic or a coating. In one example, the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, WO3. In one example, the average particle size of the photocatalyst ranges from about 20 nm to about 1000 nm. In one example, the average particle size of the plasmonic nanoparticles ranges from about 30 nm to about 70 nm. In one example, the plasmonic nanoparticles are non-oxidizable. In one example, the plasmonic nanoparticles comprise one or more of metals, semiconductors and metalloids. In one example, the plasmonic nanoparticles comprise one or more of gold, platinum, silver, copper, zinc and nickel. In one example, the plasmonic nanoparticles comprise one or more of silicon, germanium, selenium and gallium. In one example, the plasmonic nanoparticles comprise one or more of boron, silicon and germanium.

[0015] A system for purifying a fluid is also disclosed.

[0016] In one example, a system includes a housing and a light source detachably coupled to the housing, the light source configured to emit radiation at a predetermined frequency. The system also includes a substrate positioned between the housing and the light source, the substrate including plasmonic nanoparticles configured to emit radiation at the predetermined frequency, and a space defined by the housing configured to receive a fluid.

[0017] In one example, the system includes a fan positioned and configured to draw a fluid through the space and past the substrate. In one example, the fluid is air. In one example, the wavelength of the radiation ranges from about 350 nm to about 420 nm. In one example, the average particle size of the plasmonic nanoparticles ranges from about 1 / 2 to about 1 / 15 of the wavelength of the radiation emitted from the light source. In one example, the average particle size of the plasmonic nanoparticles ranges from about 30 nm to about 70 nm. In one example, the plasmonic nanoparticles are non-oxidizable. In one example, the photocatalyst includes one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one example, the average particle size of the photocatalyst ranges from about 20 nm to about 1000 nm. In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In one example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In one example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In one example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium.

[0018] An air purifier is also disclosed.

[0019] In one embodiment, an air purifier includes a filter medium coated with a coating. The coating includes a photocatalyst and plasmonic nanoparticles. The coating may also include a surfactant, such as an alcohol.

[0020] In one example, the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm. In one example, the plasmonic nanoparticles are non-oxidizable.

[0021] In one example, the photocatalyst includes one or more of TiO 2 , ZnO, SnO 2 , CdS, and WO 3 . In another example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

[0022] In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In another example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium.

[0023] A method of making an article for purifying a fluid is also disclosed.

[0024] In one example, the method includes providing a substrate having a first surface opposite a second surface, mixing a photocatalyst with plasmonic nanoparticles to produce a coating composition, applying the coating composition to one of the first surface and the second surface of the substrate, and drying the coating composition to produce a decontamination coating. In one example, the method further includes mixing a surfactant with the photocatalyst and the plasmonic nanoparticles. In one example, the surfactant is an alcohol.

[0025] In one embodiment, the substrate is a filter. In another embodiment, the substrate comprises a fiber material, a fabric, a metal, a cellulosic material, a ceramic, or a coating. In one embodiment, the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one embodiment, the average particle size of the photocatalyst ranges from about 20 nm to about 1000 nm.

[0026] In one example, the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm. In one example, the plasmonic nanoparticles are non-oxidizable. In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In one example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium.

[0027] Other application areas of the present disclosure will be apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are only intended for illustrative purposes and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The specific embodiments of the present disclosure will be better understood when read in conjunction with the accompanying drawings. However, it should be understood that the present disclosure is not limited to the precise arrangements and instrumentalities of the examples shown in the drawings.

[0029] Figure 1 is a schematic diagram of a substrate coated with a material composition;

[0030] Figure 2 is a schematic diagram of a system for purifying a fluid;

[0031] Figure 3 is a graph showing the reaction rates of materials that destroy organic chemicals; and

[0032] Figure 4 is a graph showing the reaction rates of materials that destroy organic chemical substances. DETAILED DESCRIPTION

[0033] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses.

[0034] As used throughout, ranges are used as shorthand for describing each value within the range. Any value within a range can be selected as the endpoint of the range. In addition, all references cited herein are incorporated herein by reference in their entirety. In the event of a conflict between a definition in the present disclosure and a definition in the cited reference, the present disclosure shall prevail.

[0035] The description of the illustrative examples according to the principles of the present disclosure is intended to be read in conjunction with the accompanying drawings, which are considered to be part of the entire written description. In the description of the examples of the disclosure disclosed herein, any reference to direction or orientation is intended only for ease of description and is not intended to limit the scope of the disclosure in any way. Relative terms, such as "below," "above," "horizontally," "vertically," "above," "below," "up," "down," "top," and "bottom," and their derivatives (e.g., "horizontally," "downwardly," "upwardly," etc.) should be interpreted as referring to the orientation described subsequently or shown in the accompanying drawings in question. These relative terms are for ease of description only and, unless expressly noted, do not require that the devices be constructed or operated in a specific orientation.

[0036] Terms such as "attach," "attach," "connect," "couple," "interconnect," and similar terms refer to a relationship in which structures are fixed or attached to one another directly or indirectly through intermediate structures, as well as removable or rigid attachments or relationships, unless expressly described otherwise. Furthermore, the features and benefits of the present disclosure are illustrated by reference to exemplary embodiments. Therefore, the present disclosure should obviously not be limited to the exemplary embodiments showing some possible non-limiting combinations of features, which may exist alone or in other combinations of features; the scope of the present disclosure is defined by the appended claims.

[0037] Unless otherwise indicated, all percentages and amounts expressed herein and elsewhere in this specification are to be understood as referring to percentages by weight. The amounts given are based on the active weight of the material. As used herein, the term "about" refers to + / - 5% of the reference value. As used herein, the term "substantially free" refers to less than about 0.1 wt % based on the total weight of the reference value.

[0038] The present disclosure relates to materials, articles and systems for removing pollutants from fluids (e.g., air). Many existing air purification technologies focus on filtering particulate matter, such as HEPA filters. HEPA filters cannot effectively remove viruses and VOCs.

[0039] In recent years, photocatalytic oxidation (PCO) and photoelectrochemical oxidation (PECO) technologies have been developed. PCO overcomes the ineffectiveness of HEPA filters against viruses and VOCs, however, the PCO process is slow and has low quantum efficiency. PCO is a photocatalytic technology that aims to disinfect and purify (detoxify) indoor air. In PCO technology, when light of a specific wavelength is absorbed on a semiconductor, if the energy of the photon exceeds the band gap of the semiconductor, it releases an electron from the semiconductor, leaving a "hole" in the semiconductor material. If water molecules are present at the site of the semiconductor in the form of negatively charged hydroxide ions and positively charged hydrogen ions, the hydroxide ions give up their electrons to fill the "hole", and they become hydroxyl "radicals" in the process. The hydroxyl radicals then oxidize any organic chemicals in the presence of oxygen. PCO technology is effective, but can be slow.

[0040] PECO overcomes the shortcomings of both HEPA filters and PCO technology. In PECO technology, a metallic mesh provides a metallic path for free electrons to move away from holes, improving the quantum efficiency of the photocatalytic oxidation process. This improvement increases the efficiency and speed of the photocatalytic oxidation process by multiple orders of magnitude.

[0041] The present disclosure relates to improved materials and systems for purifying fluids. In one example, the present disclosure includes a unique mixture of a photocatalyst and metal alloy nanoparticles that enhances the photocatalyst's ability to destroy viruses and other organic contaminants.

[0042] In one or more embodiments, photocatalysts using metal oxide photocatalysts and metal alloy nanoparticles are combined in a manner that enhances and accelerates chemical reactions that destroy viruses, bacteria, mold, spores and other microorganisms, volatile organic chemicals (VOCs) emitted from many indoor materials (such as paints, coatings and carpets) and foods, and allergens (such as dust mites and cockroach feces, etc.).

[0043] The disclosure described herein has several advantages over conventional PECO technology. First, the disclosure described herein utilizes plasmon photonic technology, which increases the efficiency and speed of the photocatalytic process by more than 50% compared to conventional PECO technology.

[0044] When the electromagnetic energy of a light wave incident on a nanoparticle pulls electrons away from the nucleus, the nucleus pulls the electrons back. The electrons move back and forth like a wave, creating surface plasmons, also known as EM-excited plasmons. If the plasmon's natural frequency matches the frequency of the incident electromagnetic radiation, resonance occurs, causing the nanoparticle to absorb more photons than a typical catalytic nanoparticle. This process is called a plasmonic photon process, and the nanoparticles that induce it are called plasmonic nanoparticles.

[0045] The performance of the PECO process can be compromised when the metal is oxidized. Therefore, a thin coating of a non-porous material, such as silicon oxide, can be used on the precious metal to protect it from oxidation. However, the net effect of an additional layer of silicon oxide, or any other material, no matter how thin, is to degrade the performance of the coated metal.

[0046] Plasmonic particle layers coated on photocatalysts are known and their role in enhancing the performance of photocatalytic oxidation processes. However, it is also known that performance degrades in as few as 2-3 cycles due to oxidation of the plasmonic particles. Subsequently, it was proposed to add a layer of silicon oxide on top of the plasmonic layer. This demonstrated that the protective silicon oxide layer slowed down the oxidation process but also reduced performance. Deposition of the protective silicon oxide layer by electron beam methods was described, but it is very complex and therefore expensive.

[0047] The present disclosure overcomes the problems associated with metal oxidation by using a very simple innovation of metal alloy nanoparticles for photonic processes, which do not lose their performance over time. By using nanoparticles of a metal alloy (e.g., a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids)), the nanoparticles of the metal alloy can become non-oxidizing. Therefore, the present disclosure maintains its enhanced performance for a long time and does not require the additional step of coating the precious metal nanoparticles.

[0048] In one or more examples of the present disclosure, the material composition includes metal alloy nanoparticles. These nanoparticles can include one or more metals, one or more semiconductors and / or one or more metalloids. In one or more examples, the one or more metals can include transition metals (e.g., noble metals such as gold, platinum, silver, copper, zinc, nickel, etc.). In one or more examples, the one or more semiconductors can include silicon, germanium, selenium, gallium, etc. In one or more examples, the one or more metalloids can include boron, silicon, germanium, etc.

[0049] In one or more embodiments, at least one metal can have an excess of electrons in the conduction band, while at least one alloy material (e.g., one or more alloying metals, one or more alloying semiconductors, and / or one or more alloying metalloids) can have a relatively empty outermost valence band. The material with the relatively empty valence band can scavenge one or more electrons from the metal having some high-energy electrons in the conduction band. In one or more embodiments, the electron scavenger material in the alloy can render the alloy non-oxidizable.

[0050] In one or more examples, the size of the plasmonic nanoparticles of the metal alloy can be approximately in the range of about 1 / 2 to about 1 / 15 of the wavelength of the incident light. In one or more examples, the wavelength of the incident light can be in the range of about 320 nm to about 450 nm, including all values ​​and subranges thereof. In one or more examples, the size of the nanoparticles of the metal alloy can be in the range of about 20 nm to about 225 nm, including all values ​​and subranges thereof.

[0051] In one or more examples, the photocatalyst may include TiO2, ZnO, SnO2, CdS, WO3, etc. In one or more examples, the size of the photocatalyst may be in the range of about 20 nm to about 1000 nm, including all values ​​and subranges thereof. In one or more examples, the size of the photocatalyst may be several microns. In one or more examples, when the size of the photocatalyst may be less than several microns (e.g., in the range of about 20 nm to about 1000 nm, including all values ​​and subranges thereof), higher efficiency may be achieved.

[0052] In one or more embodiments, a mixture of photocatalysts and plasmonic nanoparticles can be applied to a surface to disinfect and purify indoor air. In one or more embodiments, nanoparticles of a photocatalyst (e.g., TiO2, ZnO, SnO2, CdS, WO3, etc.) can be mixed with nanoparticles of a surfactant (e.g., an alcohol), a metal salt (e.g., a metal chloride or nitrate, etc.), and / or a metal alloy or metal oxide to produce a mixture (e.g., a slurry).

[0053] In one or more embodiments, a surface (e.g., a substrate surface) can then be coated with the mixture and dried by heating the substrate. As will be discussed in more detail below, when the surface is exposed to UV-Vis light and VOCs, the VOCs can be oxidized at a rate 45%-60% faster than conventional PECO technology. The present disclosure can be applied to a variety of substrates, such as fibers, fabrics, filters, metals, metal foils, wallpaper, wall paint, etc., to disinfect and purify indoor air. Disclosed herein is an air purifier that disinfects and purifies indoor air using the materials described herein.

[0054] In one or more instances, the disclosed modified catalysts (e.g., catalysts modified with a metal salt, another metal, plasmonic nanoparticles, etc.) generate positive ions that temporarily absorb electrons released from the photocatalyst (e.g., TiO2, ZnO, SnO2, CdS, WO3, etc.) when incident photons are absorbed by the photocatalyst. This temporary absorption of free electrons facilitates the reaction of the present disclosure that destroys viruses and other organic pollutants / contaminants without the need for providing a metal mesh on the photocatalyst as required in certain conventional PECO technologies. In addition, the material and size of the selected nanoparticles generate specific photon waves around them. These photon waves interfere with the photons of the incident light, thereby generating resonance, which increases the number of hydroxyl radicals by an order of magnitude compared to conventional PECO technologies. Therefore, the present disclosure can be referred to as a photonic technology.

[0055] In one or more embodiments, the present invention can accelerate the destruction of organic contaminants by more than 50% compared to conventional PECO technology. In addition, as described above, the presence of electron scavenger materials in the metal alloy nanoparticles can render the alloy non-oxidizable, thereby providing stable, enhanced performance over a long period of time.

[0056] Therefore, disclosed herein is a material composition for purifying a fluid, comprising a photocatalyst and nanoparticles of a non-oxidizing metal alloy.

[0057] In one example, the non-oxidizing metal alloy comprises a metal and an electron scavenger. In one example, the nanoparticles are plasmonic nanoparticles. In another example, the non-oxidizing metal alloy comprises a transition metal. In another example, the non-oxidizing metal alloy comprises one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the non-oxidizing metal alloy comprises a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids).

[0058] In one example, the photocatalyst includes one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm. In another example, the nanoparticles of the non-oxidizing metal alloy have an average particle size ranging from about 30 nm to about 70 nm.

[0059] In one example, the material composition is configured to emit radiation at a frequency having a wavelength in the range of about 350 nm to about 420 nm. In another example, the material composition is configured to emit radiation at a frequency substantially equal to a frequency of ambient radiation.

[0060] In one embodiment, the material composition includes a surfactant. In one embodiment, the surfactant is an alcohol.

[0061] Reference Figure 1 , also disclosed is an article 100 for purifying a fluid. In one example, the article 100 includes a substrate 110 having a first surface 112 opposite a second surface 114, and a coating 120 on one of the first surface 112 and the second surface 114. The coating 120 includes a photocatalyst and plasmonic nanoparticles.

[0062] In one example, substrate 110 includes a fiber material, a fabric, a metal, a cellulose material, a ceramic, or a coating. In one example, the photocatalyst includes one or more of TiO2, ZnO, SnO2, CdS, and WO3. In another example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

[0063] In one example, the average particle size of the plasmonic nanoparticles ranges from about 30 nm to about 70 nm. In another example, the plasmonic nanoparticles are non-oxidizable. In another example, the plasmonic nanoparticles include one or more metals, semiconductors, and metalloids. In another example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium. In another example, the plasmonic nanoparticles include a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids).

[0064] Reference Figure 2 , also disclosed is a system 200 for purifying a fluid. System 200 includes a housing 240 having an inlet 242 and an outlet 244, and defining a space 246. System 200 also includes an energy source, such as a light source 230, removably coupled to housing 240. Light source 230 is configured to emit electromagnetic radiation at a predetermined frequency. In one example, light source 230 emits electromagnetic radiation at an ultraviolet frequency.

[0065] The system 200 further includes a substrate 210 positioned between the housing 240 and the light source 230. The substrate 210 includes plasmonic nanoparticles configured to emit radiation at a predetermined frequency. In one example, the radiation has a wavelength ranging from about 350 nm to about 420 nm.

[0066] The system 200 also includes a space 246 defined by the housing 240 and configured to receive a fluid. In one example, the fluid is air. In one example, the system 200 includes a fan 260 located near the outlet 244 and configured to draw the fluid from the inlet 242 through the space 246 so that the fluid passes over the substrate 210. The system 200 may also include a transparent layer 220, such as UV-A transparent glass, located between the substrate 210 and the light source 230.

[0067] When passing through substrate 210, the fluid is positioned so that electromagnetic radiation emitted from light source 230 and substrate 210 destroys contaminants in the fluid, thereby purifying the fluid. The fluid can then be drawn to outlet 244 of housing 240 so that the purified fluid is discharged from housing 240.

[0068] In one example, the average particle size of the plasmonic nanoparticles ranges from about 1 / 2 to about 1 / 15 the size of the wavelength of radiation emitted from light source 230. In one example, the average particle size of the plasmonic nanoparticles ranges from about 30 nm to about 70 nm. In another example, the plasmonic nanoparticles are non-oxidizable.

[0069] In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In one example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium. In another example, the plasmonic nanoparticles include a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids).

[0070] In one example, the photocatalyst includes one or more of TiO 2 , ZnO, SnO 2 , CdS, and WO 3 . In one example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

[0071] Also disclosed is an air purifier comprising a filter medium coated with a coating comprising a photocatalyst and plasma nanoparticles.

[0072] In one embodiment, the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm. In one embodiment, the plasmonic nanoparticles are non-oxidizable. In one embodiment, the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one embodiment, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

[0073] In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In another example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium. In another example, the plasmonic nanoparticles include a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids).

[0074] Also disclosed is a method of making an article 100 for purifying a fluid. In one example, the method includes providing a substrate 110 having a first surface 112 opposite a second surface 114.

[0075] The method further includes mixing the photocatalyst with the plasmonic nanoparticles to produce a coating composition. In one example, the method further includes mixing a surfactant with the photocatalyst and the plasmonic nanoparticles. In one example, the surfactant is an alcohol. The method further includes applying the coating composition to one of the first surface and the second surface of the substrate, and drying the coating composition to produce the purification coating 120.

[0076] In one example, substrate 110 is a filter. In one example, substrate 110 comprises a fiber material, a fabric, a metal, a cellulosic material, a ceramic, or a coating. In one example, the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3. In one example, the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm. In one example, the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm. In another example, the plasmonic nanoparticles are non-oxidizable.

[0077] In one example, the plasmonic nanoparticles include one or more of a metal, a semiconductor, and a metalloid. In another example, the plasmonic nanoparticles include one or more of gold, platinum, silver, copper, zinc, and nickel. In another example, the plasmonic nanoparticles include one or more of silicon, germanium, selenium, and gallium. In another example, the plasmonic nanoparticles include one or more of boron, silicon, and germanium. In another example, the plasmonic nanoparticles include a metal alloy of three to four different materials (e.g., metals, semiconductors, and / or metalloids).

[0078] Example

[0079] The following examples include experiments conducted to demonstrate the improvements of the present disclosure described herein for the destruction of organic chemicals, including microorganisms, which are also organic in nature.

[0080] Experimental setup

[0081] Figure 2 The schematic diagram shows the experimental setup. Specifically, Figure 2 A schematic diagram of a photocatalytic oxidation reactor is shown with the reactor and sample mounted, along with the reactor chamber. Not shown are the probes and instrumentation incorporated into the system to collect reaction rate data.

[0082] Exemplary formulations

[0083] The following exemplary formulations were tested:

[0084] A: Control base PECO: nano-TiO2 (99%) + metal salt (1%)

[0085] B: Control A plasmonic nanoparticles

[0086] Each formulation was tested at least 20 times. The performance was consistent each time. All experimental results for these formulations are given in Figure 3 and 4 These figures show data for all test samples of these formulations. The reaction rate constants were calculated for each of these formulations and compared to the base PECO formulation.

[0087] The calculated reaction rate constants for these formulations include:

[0088] Control PECO = 15.5 x 10 -3 min -1 , plasma photons = 24.9x10 -3 min -1 .

[0089] Therefore, from the experimental data collected, the improvement of the plasmonic photonic formulation over the control is 60.7% due to the addition of plasmonic nanoparticles.

[0090] Figure 3 The performance of the disclosed plasma photon formulation is shown compared to a control PECO formulation A. The graph shows the breakdown of toluene (a VOC) over time in a test chamber. The control line shows the performance of the PECO control, and the example line shows the improved efficiency of the plasma photon.

[0091] Figure 4 The graph shows that the reaction rate constants remain stable within experimental error for the disclosed formulations. Each sample shows the plasma photonic coating over multiple runs. The bar graph indicates that the performance within the error bars is roughly the same. In other words, it shows that performance does not degrade over multiple runs.

[0092] Although the present disclosure has been described with reference to a number of embodiments, these embodiments have been described in considerable detail for the purpose of providing a complete disclosure. However, such embodiments are merely representative and are not intended to limit or represent an exhaustive list of all aspects of the present disclosure. The scope of the present disclosure is to be determined by the appended claims. Moreover, it will be apparent to those skilled in the art that various changes may be made to such details without departing from the spirit and principles of the present disclosure.

Claims

1. A material composition for purifying a fluid, comprising: photocatalysts; and Nanoparticles of non-oxidizing metal alloys.

2. The material composition of claim 1, wherein the non-oxidizing metal alloy comprises a metal and an electron scavenger.

3. The material composition of claim 1, wherein the non-oxidizing metal alloy comprises a transition metal.

4. The material composition of claim 1, wherein the non-oxidizing metal alloy comprises one or more of gold, platinum, silver, copper, zinc, and nickel.

5. The material composition of claim 1, wherein the nanoparticles of the non-oxidized metal alloy are plasmonic nanoparticles. The material composition according to claim 1 , wherein the photocatalyst comprises one or more of TiO 2 , ZnO, SnO 2 , CdS, and WO 3 .

7. The material composition of claim 1, wherein the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

8. The material composition of claim 1, wherein the nanoparticles of the non-oxidized metal alloy have an average particle size ranging from about 30 nm to about 70 nm.

9. The material composition of claim 1, configured to emit radiation at a frequency having a wavelength in the range of about 350 nm to about 420 nm. 10 . The material composition according to claim 1 , further comprising a surfactant. The material composition according to claim 10 , wherein the surfactant is an alcohol.

12. An article for purifying a fluid, the article comprising: a substrate having a first surface opposite a second surface; as well as a coating on one of the first surface and the second surface, the coating comprising: photocatalysts; as well as Plasmonic nanoparticles.

13. The article of claim 12, wherein the substrate comprises a fibrous material, a fabric, a metal, a cellulosic material, a ceramic, or a coating.

14. The article of claim 12, wherein the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, WO3.

15. The article of claim 12, wherein the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

16. The article of claim 12, wherein the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm.

17. The article of claim 12, wherein the plasmonic nanoparticles are non-oxidizable.

18. The article of claim 12, wherein the plasmonic nanoparticles comprise one or more of a metal, a semiconductor, and a metalloid.

19. The article of claim 12, wherein the plasmonic nanoparticles comprise one or more of gold, platinum, silver, copper, zinc, and nickel.

20. The article of claim 12, wherein the plasmonic nanoparticles comprise one or more of silicon, germanium, selenium, and gallium.

21. The article of claim 12, wherein the plasmonic nanoparticles comprise one or more of boron, silicon, and germanium.

22. A system for purifying a fluid, the system comprising: a housing defining a volume configured to receive a fluid; a light source detachably coupled to the housing, the light source being configured to emit radiation at a predetermined frequency; as well as A substrate is positioned between the housing and the light source, the substrate comprising plasmonic nanoparticles configured to emit radiation at the predetermined frequency.

23. The system of claim 22, further comprising a fan located near the outlet of the housing, the fan configured to draw fluid through the space such that the fluid passes over the substrate.

24. The system of claim 22, wherein the fluid is air.

25. The system of claim 22, wherein the radiation has a wavelength in the range of about 350 nm to about 420 nm.

26. The system of claim 22, wherein the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, WO3.

27. The article of claim 22, wherein the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

28. The system of claim 22, wherein the average particle size of the plasmonic nanoparticles ranges from about 1 / 2 to about 1 / 15 the size of a wavelength of radiation emitted from the light source.

29. The system of claim 22, wherein the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm.

30. The system of claim 22, wherein the plasmonic nanoparticles are non-oxidizable.

31. The system of claim 22, wherein the plasmonic nanoparticles comprise one or more of a metal, a semiconductor, and a metalloid.

32. The system of claim 22, wherein the plasmonic nanoparticles comprise one or more of gold, platinum, silver, copper, zinc, and nickel.

33. The system of claim 22, wherein the plasmonic nanoparticles comprise one or more of silicon, germanium, selenium, and gallium.

34. The system of claim 22, wherein the plasmonic nanoparticles comprise one or more of boron, silicon, and germanium.

35. An air purifier comprising: A filter medium coated with a coating comprising: photocatalysts; and Plasmonic nanoparticles.

36. The air purifier according to claim 35, wherein the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3.

37. The air purifier of claim 35, wherein the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

38. The air purifier of claim 35, wherein the average particle size of the plasmonic nanoparticles ranges from about 30 nm to about 70 nm.

39. The air purifier of claim 35, wherein the plasmonic nanoparticles are non-oxidizable.

40. The air purifier of claim 35, wherein the plasmonic nanoparticles comprise one or more of a metal, a semiconductor, and a metalloid.

41. The air purifier of claim 35, wherein the plasmonic nanoparticles comprise one or more of gold, platinum, silver, copper, zinc, and nickel.

42. The air purifier of claim 35, wherein the plasmonic nanoparticles comprise one or more of silicon, germanium, selenium, and gallium.

43. The air purifier of claim 35, wherein the plasmonic nanoparticles comprise one or more of boron, silicon, and germanium.

44. A method of making an article for purifying a fluid, the method comprising: providing a substrate having a first surface opposite a second surface; mixing a photocatalyst with plasmonic nanoparticles to produce a coating composition; applying the coating composition to one of the first surface and the second surface of a substrate; as well as The coating composition is dried to produce a clear coating.

45. The method of claim 44, wherein the substrate is a filter.

46. ​​The method of claim 44, wherein the substrate comprises a fibrous material, a fabric, a metal, a cellulosic material, a ceramic, or a coating.

47. The method of claim 44, wherein the photocatalyst comprises one or more of TiO2, ZnO, SnO2, CdS, and WO3.

48. The method of claim 44, wherein the photocatalyst has an average particle size ranging from about 20 nm to about 1000 nm.

49. The method of claim 44, wherein the plasmonic nanoparticles have an average particle size ranging from about 30 nm to about 70 nm.

50. The method of claim 44, wherein the plasmonic nanoparticles are non-oxidizable.

51. The method of claim 44, wherein the plasmonic nanoparticles comprise one or more of a metal, a semiconductor, and a metalloid.

52. The method of claim 44, wherein the plasmonic nanoparticles comprise one or more of gold, platinum, silver, copper, zinc, and nickel.

53. The method of claim 44, wherein the plasmonic nanoparticles comprise one or more of silicon, germanium, selenium, and gallium.

54. The method of claim 44, wherein the plasmonic nanoparticles comprise one or more of boron, silicon, and germanium.

55. The method of claim 44, further comprising mixing a surfactant with the photocatalyst and plasmonic nanoparticles.

56. The method of claim 44, wherein the surfactant is an alcohol.

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