Patent Grant
11896961
The present invention relates to combines the advantages of fabrication of semiconductor heterostructure (Ag3PO4—WO3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (Pt—Ag/Ag3PO4—WO3) for visible light assisted H2 generation utilizing the aqueous bio-alcohols.
Renewable hydrogen (H2) and associated fuel cell technologies will play a major role in the development of clean energy and sustainable growth of the global economy [1]. Transitioning to a H2 economy has the potential to decarbonize electricity and heat generation, and transportation, thereby reducing greenhouse gas emissions and anthropogenic climate change. There are several routes to renewable H2 production, including the thermochemical reforming of fossil fuels or renewable organic feedstocks and electrochemical and/or photo(electro)chemical water splitting. The H2 gas is commonly produced by steam reforming of naphtha or coal gasification [2], which both produce significant greenhouse gases [3]. The high cost of renewable H2 represents a significant barrier to its adoption in the energy sector over conventional fossil fuel technologies, suggesting that the current industrial dependence on fossil fuels will persist for the foreseeable future [4]. This is because, the water splitting is limited by the current availability of renewable electricity and requirement for lower cost electrolyzers [5]. The H2 production may use only renewable energy sources such as bio-alcohols, if obtained e.g. via photocatalysis or photoelectrochemical water splitting exploiting solar energy.
A common approach to activate a visible spectral response on semiconductor surfaces is to decorate them with metallic nanostructures that support localized surface plasmon resonance (LSPR) [6,7]. It is well known that the absorption of light by LSPR of metal nanostructures is tunable and depends strongly on the size, shape, aspect ratio of the nanostructures, the dielectric properties of both metal and the surrounding environment [8,9]. When deposited on semiconductor support, plasmonic nanostructures generate charge carriers so-called hot electrons, which can be injected into the semiconductor substrate. Upon visible light illumination, hot electrons are generated at metallic nanoparticles (Me-NPs) deposited on a semiconductor; therefore, they can be utilized in a photoelectrochemical configuration for water splitting. Several plasmon-induced Me-NPs/semiconductor photoelectrodes combinations have been proposed to enhance photoelectrochemical activity varying the semiconductor morphology and noble metals. In most cases, mono metallic species such as Au, Ag and Pt were utilized as plasmonic metals.
Furthermore, it was demonstrated that plasmonic effects in semiconductors are influenced substantially by the Fabry-Perot interference observed within metal oxides. By a control design of the semiconductor heterostructures, it is possible to fabricate the Fabry-Perot interference pattern to the plasmonic band(s) of metallic nanoparticles to efficiently utilize “hot” electron excitation/injection events. By proper adjustment of the Fabry-Perot interference pattern in the visible spectral range, the enhancement of both the intraband plasmonic excitation of s-band electrons and the interband transition of d-band electrons are expected [10].
Different nanosized semiconductors such as ZnO, TiO2, SnO2 and g-C3N4 etc. were used for H2 production after applying various techniques to overcome the limitations of individual semiconductors [11]. Recently, silver orthophosphate (Ag3PO4) is extensively reported due to its high catalytic activities for photo-oxidation, photo degradation of organic pollutants and it also possessing antifouling properties [12]. Although, Ag3PO4 semiconductor has significant promising property to generate the oxygen, it has limited applications and directly not applied for hydrogen production from water due to its low conduction band potential and photo stability [13]. Number of Ag3PO4 based nanocomposites, such as Ag/Ag3PO4/BiVO4 [14], g-C3N4/MoS2/Ag3PO4 [15], g-C3N4/Ag3PO4 [16, 17] and Ag/Ag3PO4/WO3 were prepared and applied for photo degradation of organic pollutants [18]. It was reported that Ag3PO4 effectively enhance the separation of electron-hole pair after application of light energy as development of strong electric field at the interface of Ag3PO4. Tungsten trioxide (WO3) is a well-known n-type semiconductor with smaller band gap (2.4-2.8 eV). It has exhibited good photocatalytic activities with high photo corrosion resistant properties [19]. Due to its lower conduction band level, pure WO3 exhibited fast recombination activities and cannot reach to sufficient potential to react with electron acceptors [20]. To overcome this limitation, some researchers utilized nanosized WO3 for an effective charge separation [21]. Further, it is widely reported that presence of noble metal nanoparticles on the surface of semiconductor could induce LSPR, which enhance the visible-light absorption and drastically decrease the recombination of photo-generated electron-hole system. Different heterostructures based on WO3 with noble metals such as TiO2/Pt/WO3 [22], TiO2@WO3/Au [23], Ag3PO4/Ag/WO3-x [24], and Ag/Ag3PO4/WO3 were reported for excellent photocatalytic activities for photodegradation of organic compounds. However, there is no specific research reported for synthesis of Pt and Ag metals decorated Ag3PO4—WO3 heterostructure and its utilization of photo catalytic hydrogen production from bio-alcohols.
To address the foregoing problems, in whole or in part, and/or other problems that may have been observed by persons skilled in the art, the present disclosure provides compositions and methods as described by way of example as set forth below.
The present invention combines the advantages of fabrication of semiconductor heterostructure (Ag3PO4—WO3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (Pt—Ag/Ag3PO4—WO3) for visible light assisted H2 generation utilizing the aqueous bio-alcohols. A deep-rooted vision of this research is to provide new business opportunities in the future realizing the Kingdom of Saudi Arabia's Vision 2030 (a strategic framework to reduce Saudi Arabia's dependence on oil, diversify its economy, and develop public service sectors such as health, education, infrastructure, recreation, and tourism).
Crystalline Ag3PO4 and WO3 nanofibers were synthesized by microwave and electrospinning methods. Three different WO3 nanofibers composition (5, 10 and 15 wt. %) were used to obtain Ag3PO4/WO3 nanocomposite heterostructures, which are effective visible light active photo catalysts. Further, a simple, enviro-friendly, and cost-effective biogenic synthesis method have been achieved using Salvia officinalis extract to decorate Pt and Ag metal nanoparticles on the surface of Ag3PO4—WO3 composites. Presence of bioactive agents in the extract are responsible for the Pt and Ag3PO4 reduction and for prevention of the Pt nanoparticles from aggregation in aqueous medium. Various analytical techniques such as XRD, SEM, FT-IR, DR UV-vis, XPS and N2-physisorption were utilized to characterize the synthesized photocatalysts. The band gap energy values were decreased after decoration of Pt and Ag metal nanoparticles over Ag3PO4—WO3 nanocomposites. The Pt and Ag metal nanoparticles decorated Ag3PO4—WO3 (10 wt %) nanocomposite exhibited highest photo catalytic activity for H2 production from bioethanol due to possession of unique physico-chemical properties low band gap and surface area. In addition, presence of plasmonic nanoparticles assisted for the efficient electron trap to decrease the e−-h+ recombination rate to enhance the hydrogen production.
Accordingly, in one embodiment, the invention relates to crystalline Ag3PO4—WO3 composite nanofibers comprising 5 to 15 wt. % WO3, wherein the composite nanofibers are visible light active photo catalysts. In some embodiments, the composite nanofibers are produced by a process comprising the steps of:
In still further embodiments, a process is provided for making crystalline Ag3PO4—WO3 composite nanofibers, the process comprising the steps of:
Additional features of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
Having thus described the subject matter of the present invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The subject matter of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the subject matter of the present invention are shown. Like numbers refer to like elements throughout. The subject matter of the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Indeed, many modifications and other embodiments of the subject matter of the present invention set forth herein will come to mind to one skilled in the art to which the subject matter of the present invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention. Therefore, it is to be understood that the subject matter of the present invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.
Optimization of Photocatalytic Hydrogen Generation Using Aqueous Bio-Alcohols and Plasmonic Metals Deposited on Semiconductor Composite Nanofibers
The present invention combines the advantages of fabrication of semiconductor heterostructure (Ag3PO4—WO3) with plasmonic metals (Pt and Ag) with optical interference to optimize the visible light photo response of plasmonic metals deposited semiconductor (Pt—Ag/Ag3PO4—WO3) for visible light assisted H2 generation utilizing the aqueous bio-alcohols.
Crystalline Ag3PO4 and WO3 nanofibers were synthesized by microwave and electrospinning methods. Three different WO3 nanofibers composition (5, 10 and 15 wt. %) were used to obtain Ag3PO4/WO3 nanocomposite heterostructures, which are effective visible light active photo catalysts. Further, a simple, enviro-friendly, and cost-effective biogenic synthesis method have been achieved using Salvia officinalis extract to decorate Pt and Ag metal nanoparticles on the surface of Ag3PO4—WO3 composites. Presence of bioactive agents in the extract are responsible for the Pt and Ag3PO4 reduction and for prevention of the Pt nanoparticles from aggregation in aqueous medium. Various analytical techniques such as XRD, SEM, FT-IR, DR UV-vis, XPS and N2-physisorption were utilized to characterize the synthesized photocatalysts. The band gap energy values were decreased after decoration of Pt and Ag metal nanoparticles over Ag3PO4—WO3 nanocomposites. The Pt and Ag metal nanoparticles decorated Ag3PO4—WO3 (10 wt %) nanocomposite exhibited highest photo catalytic activity for H2 production from bioethanol due to possession of unique physico-chemical properties low band gap and surface area. In addition, presence of plasmonic nanoparticles assisted for the efficient electron trap to decrease the e−-h-F recombination rate to enhance the hydrogen production.
Accordingly, in one embodiment, the invention relates to crystalline Ag3PO4—WO3 composite nanofibers comprising 5 to 15 wt. % WO3, wherein the composite nanofibers are visible light active photo catalysts. In some embodiments, the composite nanofibers are produced by a process comprising the steps of:
In still further embodiments, a process is provided for making crystalline Ag3PO4—WO3 composite nanofibers, the process comprising the steps of:
Preparation of Nanocomposite Samples
Synthesis of crystalline Ag3PO4 by microwave synthesis method: To synthesize crystalline Ag3PO4 powder, 0.1 M aqueous solution of (NH4)2HPO4 was slowly added to aqueous AgNO3 solution (0.15 M), then the pH of the contents was adjusted to 10 by adding the NH4OH solution to obtain a precipitate. Then, the formed precipitate was transferred into a specially designed polymer vessel with temperature and pressure-controlled sensors. The vessel was then subjected to microwave irradiation (power between 150 and 300 W) to maintain 140° C. for 30 min by using Microwave lab station (Ethos, Milestone). After the microwave treatment, the obtained material was washed with water and ethanol and dried at 80° C. for 3 h.
Synthesis of WO3 nanofibers by electrospinning method: To synthesize the WO3 nanofibers, polymethylmethacrylate (PMMA, MW=120,000) and tungsten hexachloride solutions were used as precursors. First, the PMMA was dissolved in chloroform and tungsten hexachloride was dissolved in 2-methoxyethanol and then the two solutions were mixed at 50° C. under stirring for 20 minutes under ultrasonication. The WO3 nanofibers were grown onto a silicon substrate using electrospinning device at room temperature. The solution was taken in a syringe that is positioned in the Plexiglas box and raised from a metallic support. The needle of syringe is connected to the positive electrode of the high voltage power supply. The substrate is placed on a metallic support and is grounded. The applied voltage was varied from 17 kV to 20 kV and a 15 cm distance was maintained from needle to substrate. After deposition, the sample was calcined at 500° C. to remove the PMMA and to crystallize the WO3 nanofibers.
Preparation of Ag3PO4/WO3 nanocomposites: The Ag3PO4/WO3 nanocomposites were synthesized by following a simple ultrasonication homogenization method. For the synthesis, 100 mg of WO3 was dispersed in 25 mL of ethyl alcohol and water (75:25 vol %) by sonication for 30 min. Then calculated amount of Ag3PO4 powder was added next to the dispersion and again subjected to sonication for 30 min. The resulting dispersion was heated in an electric oven at 100° C. until the complete evaporation of solvent. During the preparation, ‘x’ weight percentage of WO3 (x=5, 10 and 15 wt. %) was added to the Ag3PO4 dispersion and the obtained composites were named accordingly as AgP—W-1, AgP—W-2, and AgP—W-3 respectively.
Pt and Ag-decorated Ag3PO4—WO3 nanomaterials by green extract method: In the beginning, 20 g of clean leaves of Salvia officinalis (commonly known as ‘Sage’) were washed, dried and grinded well. Then, the grounded leaves were boiled in 100 mL of double distilled water for 30 minutes and the aqueous extract was obtained by vacuum filtration. The obtained extract was used to decorate the Pt nanoparticles over Ag3PO4—WO3 nanocomposites. Calculated amount of H2PtCl6·6H2O corresponding to 1.0 wt. % of Pt was dissolved in 90 mL of double distilled water and then 10 mL of plant extract solution was added for the reduction of Pt nanoparticles under constant stirring. Finally, calculated amount of Ag3PO4—WO3 nanocomposite powder was added and stirred for 1 h, then the excess water was removed by centrifugation. The obtained Pt and Ag metals decorated Ag3PO4—WO3 nanocomposites were dried at 100° C. and calcined at 300° C.
Characterization of Synthesized Nanomaterials
The elemental composition of the synthesized materials was determined by using ICP-AES, Optima 7300DV (PerkinElmer) instrument. The XRD patterns of the powders were collected by using PANalytical XpertPro diffractometer. The crystallite size of obtained materials was determined by applying the Debye-Scherer equation. The TEM analysis of the samples was carried out using JEOL 2100HT microscope operated at 200 kV, with images collected on a Gatan digital camera. The laser Raman spectral analysis of the samples was carried out using Bruker Equinox 55 FT-IR spectrometer equipped with an FRA106/S FT-Raman module and a liquid nitrogen cooled Ge detector using the 1064-nm line of a Nd:YAG laser with an output laser power of 200 mW. The X-ray photoelectron spectra of the samples were collected using Thermo-Scientific Escalab 250 Xi XPS instrument with Al Kα X-rays having a spot size of 650 mm. The peak shift due to charge compensation was corrected using the binding energy of C1s peak. The data was acquired using pass energy of 100 eV, dwell time 200 ms with a step size of 0.1 eV and 10-30 scans. The quantitative determination of the Pt active sites over the catalysts using CO pulse chemisorption measurements using laboratory made equipment. Prior to analysis, known amount of the sample (100 mg) was reduced at 250° C. under H2 flow (40 mL min−1) for 60 min and then cooled to 25° C. under the flow of helium gas. Then, the CO pulse injection was conducted in a flow of helium gas stream. The metal dispersion was evaluated from the amount of CO consumption (assuming CO/Pt=1). The textural properties of the samples were obtained from the N2-physisorption experiments, which were conducted using Quantachrome ASiQ adsorption system. Optical properties were measured by Thermo-Scientific evolution UV-vis spectrophotometer equipped with an integrating sphere in the wavelength range of 200-800 nm to measure the reflectance spectra of samples. Band gap energy values of all the samples were calculated using Kubelka-Munk method. The Kubelka-Munk factor (K) was determined by following equation; K=(1−R)2/2R, where R is the % reflectance. The wavelengths (nm) were translated into energies (E) and a plot was drawn between (K*E)0.5 and E to obtain a curve. The bandgap energy (eV) was obtained as the intersection point of the two slopes in the curve
Photocatalytic Reforming of Bioethanol to Hydrogen
Photocatalytic reactions were conducted in the liquid phase in a Pyrex flask under an argon atmosphere. The catalyst (150 mg) was dispersed by stirring at 500 rpm in 120 mL of a 20 vol % ethanolic aqueous solution at 25° C. for 30 min in the dark to equilibrate any adsorption processes and ensure a uniform catalyst suspension. The reactor was then evacuated and irradiated by a 300 W Xe lamp providing a flux of approximately 125 mW·cm−2 in the reaction zone for 1 h. Evolved gases flowing into the gas chromatograph sample loop through a closed gas circulation and the product analysis for H2 was carried out by using a Varian 3300 gas chromatograph with a thermal conductivity detector and a 2 m MS 13× column.
Photocatalytic Reforming Activity
The photocatalytic reforming functionality of as prepared Ag3PO4, WO3, AgP—WO3 composites and Pt—Ag decorated Ag3PO4, WO3 nanofibers, AgP—WO3 composite catalysts was tested by determining the hydrogen production from the aqueous ethanol solution. Different reaction parameters such as reaction time, methanol concentration, weight of the catalyst, pH of reactants mixture and reaction temperature were studied to optimize the reaction conditions. The obtained photocatalytic activity results are depicted in
When the reactant feed contained only water without ethanol, the H2 evolution is negligible, however H2 production increased with increase of vol % of ethanol and reached to the maximum at 20 vol. % in case of all the synthesized AgP—WO3 composites samples [
It was reported that electrostatic interactions between the photocatalyst surface and the reactants play an important role in photocatalytic activity. To study the influence of pH of the ethanol and water solution on the catalyst performance, different aqueous ethanol solutions with pH between 1 and 11 were prepared and used to photocatalytic experiments. The obtained results are plotted in
Further, we also studied the role of reaction temperature on the photocatalytic ethanol reforming activity of the catalysts between 25° C. and 85° C. [
The stability of photocatalyst under actual reaction conditions is a crucial factor in development of catalyst for any photocatalytic process because the catalysts generally undergo photo-corrosion during to catalytic tests. The stability of the Pt—Ag decorated AgP—WO3 composite catalysts was also studied. To study the reusability of the synthesized Pt—Ag/AgP—WO3 catalysts, we filtered the catalyst after the first cycle of the reaction, washed, dried, and thermally treated at 90° C. for 1 h and used the catalyst for next cycle of the reaction. The recycled catalyst was reused for five cycles The
Characterization
The phase purity and crystal structure of synthesized bare and Pt deposited WO3, Ag3PO4 and AgP—WO3 nanocomposites were determined using powder XRD analysis. As shown in the
There are no additional reflections observed in the XRD patterns of AgP—WO3 nanocomposites except for the characteristic reflections of Ag3PO4 and WO3 crystal structures (
The morphology of the synthesized samples was investigated using SEM analysis. The obtained SEM images of the representative samples are shown in
The FT-IR spectra of the Pt deposited synthesized samples are shown in
The UV-vis light absorption properties of pure and Pt—Ag decorated AgP and WO3 samples were analyzed by DR UV-vis spectroscopy measurements and the results are presented in
The textural properties of the samples are obtained from the N2 physisorption experiments and the BET surface area pore volume and pore diameter of the samples are provided in Table 1. The S BET values of pure AgP and WO3 samples are 12.5 and 35.3 m2 g−1, respectively, these observed values are much high compared to reported in the literature. This is possibly due to the different preparation conditions used in the present research. The composites of AgP and WO3 exhibited the higher surface area than pure AgP and lower than WO3. However, with increase of WO3 content, an increase surface area, pore volume was observed.
The band gap energy measurements of the synthesized materials indicated that the pure WO3 and AgP samples exhibited bandgap of 2.56 eV and 2.02 eV respectively, while band gap was slightly reduced for the AgP—WO3 composites; thus, the e−-h+ pairs could be generated on the surface of AgP, WO3 and AgP—WO3 composites under visible light irradiation. It was observed that the AgP—WO3 composites exhibited excellent photocatalytic activity for hydrogen production and considerably higher than pure AgP and WO3 catalysts under identical reaction conditions. As expected, the photocatalytic reforming activities of bulk and Pt and Ag decorated AgP—WO3 composites with different weight percent of WO3 are higher compared to non-decorated composites. The pure AgP has conduction band (CB) and valency band (VB) values of and 2.62 eV, respectively. Under the visible light irradiation, e−-h+ pairs are generated on the surfaces of both AgP and WO3. The lower catalytic activity of WO3 compared to AgP is mainly due to the more positive CB potential of WO3, as well as its less absorption of visible light. It was previously reported that the increase in photocatalytic activity of AgP—WO3 composites is mainly due to the highly effective separation of photogenerated e−-h+ pairs. Under visible light irradiation, the photogenerated e− transfer from VB to the CB of WO3 and then migrate to the VB of AgP to combine with h+. Therefore, the photo-induced e− and h+ of AgP are separated effectively, and the photogenerated e− are unceasingly moved to the CB interface of AgP. Thus, a greater number of e− are gathered on the CB interface of AgP, and more h+ are accumulated in the VB interface of WO3. It was well reported that the noble metal nanoparticles act as an efficient electron trap in order to decrease the e−-h+ recombination rate upon photoexcitation. The adsorbed ethanol molecule converted into the aldehyde after photoenergy absorption as shown in
The XPS analysis is a well-known technique to analyze the surface chemical state of the elements presented in the synthesized materials.
The peaks appeared at 373.5 eV and 367.4 eV could be attributed to Ag0 species, while the peaks at 373.0 eV and 366.7 eV are assigned to Ag+ ions for pure Ag3PO4 sample [39]. The binding energies of these peaks were shifted slightly in case of composite samples, which could be attributed to the interaction between Ag3PO4 and WO3 phases. The deconvolution of P 2p spectra of the samples reveals the phosphorous existed in three different states on the surface in case of all the samples. The samples exhibited peaks in the range of 131.7-133.2 eV for P═O, P—O—Ag and P—OH species [40]. The bulk WO3 nanofibers sample exhibited two major contributions corresponding to W 4f5/2 and W 4f7/2 at 36.5 eV and 34.5 eV, which is indicating that the most W species are in +6 oxidation state [41]. However, the binding energies of major W 4f5/2 and W 4f7/2 contributions are appeared at 37.2 eV and 35.2 eV in case of AgP—WO3 composite and Pt deposited AgP—WO3 samples. The shift in the binding energies to a high position is possibly due to the interaction between WO3 and Ag3PO4 or Ag species and they are not simply a physical mixture but composited with each other. Similar results were previously observed by the other researchers [42-43].
It is clear from the figure that the O1s spectra are different for bulk WO3, Ag3PO4, and AgP—WO3 composites. The O1s peak in WO3 can be deconvoluted into two contributions. The major peak at 529.3 eV originated from the W—O bond in the WO3 lattice and the small intensity peak at 530.3 eV corresponding to —OH groups, originated from water molecules [44]. On other hand, the bulk Ag3PO4 sample exhibited three deconvoluted O1s peaks at 533.2 eV, 531.9 eV, 529.8 eV which could be assigned to oxygen atoms for P—OH, P—O—Ag and P═O species respectively. In addition, it is observed that the O1s spectra for the AgP—WO3 composites and Pt deposited samples are consistent with WO3 and Ag3PO4, which also revealing the composition of WO3 with Ag3PO4.
The deconvoluted Pt 4f spectra for Pt deposited samples also presented in the
The surface Ag/P, O/Ag, and O/P atomic ratios for the samples were calculated using the XPS data. The Ag/P atomic ratio for AgP sample is 2.39 is more compared to Pt—AgP (2.35). The Ag/P atomic ratio in Pt—AgP—WO3 composite is around 2.44 stayed higher compared to the Pt—AgP indicating that the Pt—AgP—WO3 has a higher content of Ag0. The O/Ag atomic ratio in AgP—WO3 sample is lower than that of AgP and WO3 samples indicating that the oxygen deficiency is more in case of AgP—WO3. In addition, the ratio of O/P after Pt deposition decreased from 3.03 in AgP—WO3 to 2.95 in Pt—AgP—WO3. The generation of Ag0 and Pt0 could have resulted the oxygen vacancy, which could enhance photocatalytic performance of the materials [47].
Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as mean “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; and adjectives such as “conventional,” “traditional,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future Likewise, a group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. Furthermore, although item, elements or components of the disclosure may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing amounts, sizes, dimensions, proportions, shapes, formulations, parameters, percentages, quantities, characteristics, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are not and need not be exact, but may be approximate and/or larger or smaller as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art depending on the desired properties sought to be obtained by the subject matter of the present invention. For example, the term “about,” when referring to a value can be meant to encompass variations of, in some embodiments ±100%, in some embodiments ±50%, in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.1% from the specified amount, as such variations are appropriate to perform the disclosed methods or employ the disclosed compositions.
Further, the term “about” when used in connection with one or more numbers or numerical ranges, should be understood to refer to all such numbers, including all numbers in a range and modifies that range by extending the boundaries above and below the numerical values set forth. The recitation of numerical ranges by endpoints includes all numbers, e.g., whole integers, including fractions thereof, subsumed within that range (for example, the recitation of 1 to 5 includes 1, 2, 3, 4, and 5, as well as fractions thereof, e.g., 1.5, 2.25, 3.75, 4.1, and the like) and any range within that range.
All publications, patent applications, patents, and other references mentioned in the specification are indicative of the level of those skilled in the art to which the presently disclosed subject matter pertains. All publications, patent applications, patents, and other references are herein incorporated by reference to the same extent as if each individual publication, patent application, patent, and other reference was specifically and individually indicated to be incorporated by reference. It will be understood that, although a number of patent applications, patents, and other references are referred to herein, such reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art.
Although the foregoing subject matter has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be understood by those skilled in the art that certain changes and modifications can be practiced within the scope of the appended claims.
The present invention is a U.S. Continuation Patent Application that claims priority to U.S. Utility patent application Ser. No. 17/948,630, filed on Sep. 20, 2022, which claims priority to U.S. Provisional Patent Application No. 63/374,897, filed on Sep. 7, 2022, the entire disclosures of which are incorporated herein by reference.
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| 20130168228 | Ozin | Jul 2013 | A1 |
| 20160077069 | Kim | Mar 2016 | A1 |
| 20160334359 | Kim | Nov 2016 | A1 |
| 20180305242 | Ikeda | Oct 2018 | A1 |
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| Number | Date | Country | |
|---|---|---|---|
| 63374896 | Sep 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17948630 | Sep 2022 | US |
| Child | 18481407 | US |
