CATALYST FOR DECONTAMINATION OF AQUEOUS ENVIRONMENTS

Abstract

An embodiment herein provides a catalyst (102) for decontamination of aqueous environments. The catalyst (102) includes a perovskite material including BaSn1-xCuxO3, where x is between 0 and 0.2, its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light. The catalyst (102) generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents. The composition BaSn0.8Cu0.2O3 exhibits enhanced degradation efficiency, specifically degrading 75-80% of azo dyes in dark conditions within 2 minutes. The contaminants include organic pollutants such as azo dyes and pharmaceuticals, including antibiotics. The catalyst (102) is capable of producing RoS both under UV light and in dark conditions, thus enabling continuous water decontamination. The perovskite material is prepared using a solid-state method and is characterized by oxygen defects, which facilitate the production of reactive oxygen species in dark conditions. FIG. 1

Specification

Description:BACKGROUND
Technical Field
[0001] The embodiments herein generally relate to catalyst for Environmental Remediation, more particularly to a catalyst for decontamination of aqueous environments and a process for synthesizing the catalyst for environmental remediation and a method for remediating water contaminated with organic pollutants.
Description of the Related Art
[0002] Effluents from industries such as dye and pharmaceuticals often contain toxic contaminants exceeding WHO limits, which pollute the environment and pose serious risks to aquatic and human life. Many of these contaminants are carcinogenic and contribute to antimicrobial resistance. It is crucial to remove these contaminants from effluents before discharge. Environmental remediation processes, such as dye and pharmaceutical degradation, commonly use photocatalysts based on oxides (e.g., TiO₂). These catalysts operate through Advanced Oxidation Processes (AOPs), generating Reactive Oxygen Species (RoS) in aqueous solutions that degrade pollutants into non-toxic components, ideally converting them into CO₂ and H₂O. This allows the treated water to be repurposed.
[0003] An existing system discloses the nanocomposite, which functions as a day-night catalyst, is composed of ZnO₂ and polypyrrole. However, its limitations include complex synthesis and challenges in scalability. Another existing system discloses the perovskite-type catalyst SrCuO₃ degrades tetracycline in the dark within 120 minutes. Yet another existing system discloses a La-Sr-Co perovskite composite degrades doxycycline in the dark within 180 minutes. Yet another existing system focuses on the degradation of organic pollutants under dark ambient conditions using cerium strontium cobalt perovskite.
[0004] There is a need to address a critical gap in current technology, which typically relies on catalysts like Degussa that require sunlight or UV light for activation, rendering them ineffective in the absence of light (e.g., at night). There is a need for 'Day-Night' catalysts capable of functioning both in light and dark conditions, enabling 24/7 remediation.
SUMMARY
[0005] In view of the foregoing, an embodiment herein provides a catalyst for decontamination of aqueous environments. The catalyst includes a perovskite material including BaSn1-xCuxO3, where x is between 0.15 and 0.2, its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light. The catalyst generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents.
[0006] The catalyst is based on doped perovskite oxide, which offers a simpler, scalable synthesis process and superior performance compared to the nanocomposite. The catalyst achieves 70% degradation of methyl orange in just 2 minutes under dark conditions, demonstrating significantly faster performance. The catalyst offers a more efficient solution, with faster degradation of dyes like methyl orange under similar conditions. The catalyst generates RoS even in the absence of light, making the decontamination process more efficient and cost-effective. The catalyst eliminates the need for external light sources or additional chemicals (such as H₂O₂ in Fenton catalysts or peroxysulfate), offering a more sustainable and energy-efficient solution to environmental pollution. The catalyst aligns with UN Sustainable Development Goal (SDG) 6, which focuses on clean water and sanitation.
[0007] In some embodiments, the composition BaSn0.8Cu0.2O3 exhibits enhanced degradation efficiency, specifically degrading 75-80% of azo dyes in dark conditions within 2 minutes. In some embodiments, the contaminants include organic pollutants such as azo dyes and pharmaceuticals, including antibiotics.
[0008] In some embodiments, the catalyst is capable of producing RoS both under UV light and in dark conditions, thus enabling continuous water decontamination. In some embodiments, the perovskite material is prepared using a solid-state method and is characterized by oxygen defects, which facilitate the production of reactive oxygen species in dark conditions.
[0009] In one aspect, a method for remediating water contaminated with organic pollutants is provided. The method includes (i) providing a perovskite catalyst of the composition BaSn1-xCuxO3, (ii) exposing the contaminated water to the catalyst in both light and dark conditions, and (iii) allowing the catalyst to produce reactive oxygen species (RoS) that degrade the organic pollutants into non-toxic components both in the light and in dark conditions, without requiring additional chemical agents.
[0010] The RoS are potent oxidizing agents that degrade contaminants such as dyes and pharmaceuticals in effluents, transforming them into non-toxic substances. Typically, RoS generation requires activation by light. However, the catalyst is specifically prepared to produce RoS both in the presence of light (daytime) and in its absence (nighttime). This unique capability is due to the catalysts' chemical design, which allows RoS to be generated via a novel mechanism involving the creation of oxygen defects. As a result, the decontamination process operates continuously, 24/7, without the need for light activation.
[0011] In some embodiments, the catalyst degrades 70-80% of azo dyes, such as methyl orange, Congo Red, and Amaranth, within 2 minutes in dark conditions. In some embodiments, the catalyst degrades pharmaceutical contaminants, including antibiotics, through the generation of reactive oxygen species in both light and dark environments/conditions. In some embodiments, the water contaminants are degraded into CO2 and H2O, making the treated water safe for reuse or discharge into the environment.
[0012] In another aspect, a process for synthesizing a catalyst for environmental remediation is provided. The process includes (i) mixing BaCO3, SnO2 and CuO to synthesize the composition BaSn0.8Cu0.2O3, and (ii) employing a solid-state synthesis method to form the catalyst with oxygen vacancies, enhancing its activity for pollutant degradation in both light and dark conditions.
[0013] The catalyst has a chemical composition of BaSn₁₋ₓCuₓO₃, with values of x = 0.15, and 0.2 synthesized using the solid-state method and tested their catalytic activity. Among these, the composition with x = 0.2 demonstrates the highest catalytic activity both in the dark and under UV light. Its performance is tested against methyl orange dye, achieving a degradation rate of 75-80% in both dark conditions and under UV light irradiation. If x = above 0.2, single-phase products may not form. The sample with x = 0.2 showed the highest catalytic activity, while x = 0.15 exhibited lower catalytic activity. Samples with x = 0.0, 0.05, and 0.10 showed no catalytic activity and may not degrade dyes, indicating that only at x = 0.15 and x = 0.20 are there sufficient oxygen vacancies in the catalyst to facilitate catalytic activity.
[0001] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
[0003] FIG. 1 illustrates a process for environmental remediation using a catalyst according to an embodiment herein;
[0004] FIGS. 2A & 2B illustrate graphs to show degradation of methyl orange by a catalyst in dark condition and light condition according to an embodiment herein;
[0005] FIG. 3 is a flow diagram that illustrates a method for remediating water contaminated with organic pollutants according to an embodiment herein;
[0006] FIGS. 4A-4C illustrate High Resolution Mass Spectrometry (HR-MS spectra) of methyl orange at (a) o minute, (b) 5 minutes and (c) 30 minutes according to an embodiment herein;
[0007] FIG. 5 illustrates a degradation pathway of methyl orange according to an embodiment herein; and
[0008] FIGS. 6A & 6B illustrate generation of reactive oxygen species (RoS) by a catalyst according to an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0009] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0010] As mentioned, there remains a need for a catalyst for Environmental Remediation, more particularly to a catalyst for decontamination of aqueous environments and a process for synthesizing the catalyst for environmental remediation and a method for remediating water contaminated with organic pollutants. Various embodiments disclosed herein provide a catalyst for Environmental Remediation, more particularly to a catalyst for decontamination of aqueous environments and a process for synthesizing the catalyst for environmental remediation and a method for remediating water contaminated with organic pollutants. Referring now to the drawings, and more particularly to FIGS. 1 through 6B, where similar reference characters denote corresponding features consistently throughout the figures, preferred embodiments are shown.
[0014] An embodiment herein provides a catalyst for decontamination of aqueous environments. The catalyst includes a perovskite material including BaSn1-xCuxO3, where x is between 0.15 and 0.2, its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light. The catalyst generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents.
[0015] In some embodiments, the composition BaSn0.8Cu0.2O3 exhibits enhanced degradation efficiency, specifically degrading 75-80% of azo dyes in dark conditions within 2 minutes. In some embodiments, the contaminants include organic pollutants such as azo dyes and pharmaceuticals, including antibiotics.
[0016] In some embodiments, the catalyst is capable of producing RoS both under UV light and in dark conditions, thus enabling continuous water decontamination. In some embodiments, the perovskite material is prepared using a solid-state method and is characterized by oxygen defects, which facilitate the production of reactive oxygen species in dark conditions.
[0017] In one aspect, a method for remediating water contaminated with organic pollutants is provided. The method includes (i) providing a perovskite catalyst of the composition BaSn1-xCuxO3, (ii) exposing the contaminated water to the catalyst in both light and dark conditions, and (iii) allowing the catalyst to produce reactive oxygen species that degrade the organic pollutants into non-toxic components both in the light and in dark conditions, without requiring additional chemical agents.
[0018] In some embodiments, the catalyst degrades 70-80% of azo dyes, such as methyl orange, Congo Red, and Amaranth, within 2 minutes in dark conditions. In some embodiments, the catalyst degrades pharmaceutical contaminants, including antibiotics, through the generation of reactive oxygen species in both light and dark environments/conditions. In some embodiments, the water contaminants are degraded into CO2 and H2O, making the treated water safe for reuse or discharge into the environment.
[0019] In another aspect, a process for synthesizing a catalyst for environmental remediation is provided. The process includes (i) mixing BaCO3, SnO2 and CuO to synthesize the composition BaSn0.8Cu0.2O3, and (ii) employing a solid-state synthesis method to form the catalyst with oxygen vacancies, enhancing its activity for pollutant degradation in both light and dark conditions.
[0020] FIG. 1 illustrates a process for environmental remediation using a catalyst 102 according to an embodiment herein. FIG. 1 illustrates the process for environmental remediation using the catalyst 102 in both light and dark conditions. The catalyst 102 includes a perovskite material including BaSn1-xCuxO3, where x is between 0.15 and 0.2, its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light. The catalyst 102 generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents. In a dark condition 104 (absence of light or night), a sample of toxic pollutants is treated with the BaSn1-xCuxO3 catalyst 102. The catalyst 102 initiates a reaction with the pollutants, breaking them down into non-toxic products, even without light. This capability makes it a "night" catalyst. The progress of the reaction is monitored using UV-Vis Spectrophotometer, as shown by an absorbance graph 106. The absorbance graph 106 compares the absorbance at 0 minutes and after 2 minutes, showing a decrease in absorbance over time, which indicates the degradation of pollutants.
[0011] In a light condition 108 (presence of light or daytime), the catalyst 102 is used during the day, where the process is assisted by light. In the presence of light, the catalyst 102 accelerates the breakdown of toxic pollutants into non-toxic products, making the catalyst 102 efficient for 24x7 remediation.
[0012] This dual-functioning catalyst 102 offers continuous environmental remediation, making it effective both in the presence and absence of light, a unique advantage over traditional photocatalysts that only work under illumination.
[0021] FIGS. 2A & 2B illustrate graphs to show degradation of methyl orange by a catalyst 102 in dark condition 104 and light condition 108 according to an embodiment herein. The FIGS. 2A & 2B depicts the degradation as revealed by UV-Visible Spectroscopy. FIG. 2A illustrates a graph to show degradation of methyl orange by a catalyst 102 in dark condition 104. FIG. 2B illustrates a graph to show degradation of methyl orange by a catalyst 102 in light condition/UV light. The absorption maximum of the dye at λ, 464 nm decreases with time. It indicates the degradation of the dye. Within 2 minutes, the degradation is about 70 % and in 45 - minutes, dye degrades to 82 % in dark. Under UV irradiation, the degradation is 75 %.
[0022] In some embodiments, the catalyst 102 degrades effectively other azo dyes such as Orange II, Congo Red and Amaranth dyes in dark.
[0023] FIG. 3 is a flow diagram that illustrates a method for remediating water contaminated with organic pollutants according to an embodiment herein. At step 302, a perovskite catalyst 102 of the composition BaSn1-xCuxO3 is provided. At step 304, the contaminated water is exposed to the catalyst 102 in both light and dark conditions. At step 306, the catalyst 102 produces reactive oxygen species (RoS) that degrade the organic pollutants into non-toxic components both in the light and in dark conditions, without requiring additional chemical agents.
[0024] The RoS are potent oxidizing agents that degrade contaminants such as dyes and pharmaceuticals in effluents, transforming them into non-toxic substances. Typically, RoS generation requires activation by light. However, the catalyst 102 is specifically prepared to produce RoS both in the presence of light (daytime) and in its absence (nighttime). This unique capability is due to the catalysts' chemical design, which allows RoS to be generated via a novel mechanism involving the creation of oxygen defects. As a result, the decontamination process operates continuously, 24/7, without the need for light activation.
[0025] In some embodiments, the catalyst 102 degrades 70-80% of azo dyes, such as methyl orange, Congo Red, and Amaranth, within 2 minutes in dark conditions. In some embodiments, the catalyst 102 degrades pharmaceutical contaminants, including antibiotics, through the generation of reactive oxygen species in both light and dark environments/conditions. In some embodiments, the water contaminants are degraded into CO2 and H2O, making the treated water safe for reuse or discharge into the environment.
[0026] In an embodiment, a process for synthesizing a catalyst 102 for environmental remediation is provided. The process includes (i) mixing BaCO3, SnO2 and CuO to synthesize the composition BaSn0.8Cu0.2O3, and (ii) employing a solid-state synthesis method to form the catalyst 102 with oxygen vacancies, enhancing its activity for pollutant degradation in both light and dark conditions.
[0027] FIGS. 4A-4C illustrate High Resolution Mass Spectrometry (HR-MS spectra) of methyl orange at (a) o minute, (b) 5 minutes and (c) 30 minutes according to an embodiment herein. FIG. 4A illustrates the HR-MS spectra of methyl orange at o minute. FIG. 4B illustrates the HR-MS spectra of methyl orange at 5 minutes. 4C illustrates the HR-MS spectra of methyl orange at 30 minutes. The products of degradation are identified by HR-MS spectra in case of methyl orange. It confirms that the toxic dye gets degraded catalytically in the absence and presence of light. The intensity of peak at 328.01, characteristic of methyl orange decreases with time (FIG. 4A & FIG. 4B) and after 30 minutes (FIG. 4C) it vanishes completely confirming the degradation.
[0028] FIG. 5 illustrates a degradation pathway of methyl orange according to an embodiment herein. The degradation pathway of methyl orange is through 3 different pathways (A, B, C) as depicted in FIG. 5. The degradation mechanism is mainly through the generation of reactive oxygen species, including hydroxyl radicals (OH), superoxide radicals (O2-) which get formed by the reaction of free electrons present in the vacancies with oxygen (adsorbed or dissolved). These in turn result in other reactive oxygen species like OH radicals.
[0029] FIGS. 6A & 6B illustrate generation of reactive oxygen species (RoS) by a catalyst 102 according to an embodiment herein. The catalyst 102 includes a perovskite material including BaSn1-xCuxO3, where x is between 0 and 0.2, its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light. The catalyst has a chemical composition of BaSn₁₋ₓCuₓO₃, with values of x = 0.15, and 0.2 synthesized using the solid-state method and tested their catalytic activity. Among these, the composition with x = 0.2 demonstrates the highest catalytic activity both in the dark and under UV light. Its performance is tested against methyl orange dye, achieving a degradation rate of 75-80% in both dark conditions and under UV light irradiation. If x = above 0.2, single-phase products may not form. The sample with x = 0.2 showed the highest catalytic activity, while x = 0.15 exhibited lower catalytic activity. Samples with x = 0.0, 0.05, and 0.10 showed no catalytic activity and may not degrade dyes, indicating that only at x = 0.15 and x = 0.20 are there sufficient oxygen vacancies in the catalyst to facilitate catalytic activity. The catalyst 102 generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents. FIG. 6A illustrates the generation of reactive oxygen species (RoS) of superoxide radicals (O2-) from the catalyst 102 that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents. The production of O2 - is confirmed by the NBT degradation study as shown in FIG. 6A. FIG. 6B illustrates the generation of reactive oxygen species (RoS) of hydroxyl radicals (OH) from the catalyst 102 that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents.
[0030] The RoS result in the degradation of the dyes, particularly azo dyes. The catalyst 102 may degrade pharmaceutical antibiotics too as RoS can degrade antibiotics too. The catalyst 102 degrades dyes and antibiotics in water to non-toxic components for environmental remediation. The catalyst 102 activity is recyclable.
[0031] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of appended claims.

, Claims:I/We claim:
1. A catalyst (102) for decontamination of aqueous environments, comprising:
a perovskite material comprising BaSn1-xCuxO3, where x is between 0.15and 0.2, characterized by its ability to degrade contaminants in aqueous environments both in the presence of light and in the absence of light, wherein the catalyst (102) generates reactive oxygen species (RoS), including hydroxyl radicals (OH), superoxide radicals (O2-) that degrades contaminants in the aqueous environments both in the light and in dark conditions, without requiring additional chemical agents.

2. The catalyst (102) as claimed in claim 1, wherein the composition BaSn0.8Cu0.2O3 exhibits enhanced degradation efficiency, specifically degrading 75-80% of azo dyes in dark conditions within 2 minutes.

3. The catalyst (102) as claimed claim 1, wherein the contaminants include organic pollutants such as azo dyes and pharmaceuticals, including antibiotics.

4. The catalyst (102) as claimed claim 1, wherein the catalyst (102) is capable of producing RoS both under UV light and in dark conditions, thus enabling continuous water decontamination.

5. The catalyst (102) as claimed claim 1, wherein the perovskite material is prepared using a solid-state method and is characterized by oxygen defects, which facilitate the production of reactive oxygen species in dark conditions.

6. A method for remediating water contaminated with organic pollutants, comprising:
providing a perovskite catalyst (102) of the composition BaSn1-xCuxO3;
exposing the contaminated water to said catalyst (102) in both light and dark conditions; and
allowing the catalyst (102) to produce reactive oxygen species that degrade the organic pollutants into non-toxic components both in the light and in dark conditions, without requiring additional chemical agents.

7. The method as claimed in claim 6, wherein the catalyst (102) degrades 70-80% of azo dyes, such as methyl orange, Congo Red, and Amaranth, within 2 minutes in dark conditions.

8. The method as claimed in claim 6, wherein the catalyst (102) degrades pharmaceutical contaminants, including antibiotics, through the generation of reactive oxygen species in both light and dark environments/conditions.

9. The method as claimed in claim 6, wherein the water contaminants are degraded into CO2 and H2O, making the treated water safe for reuse or discharge into the environment.

10. A process for synthesizing a catalyst (102) for environmental remediation, comprising:
mixing BaCO3, SnO2 and CuO to synthesize the composition BaSn0.8Cu0.2O3; and
employing a solid-state synthesis method to form the catalyst (102) with oxygen vacancies, enhancing its activity for pollutant degradation in both light and dark conditions.

Dated this November 11, 2024

Arjun Karthik Bala
(IN/PA 1021)
Agent for Applicant

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