Method for degrading dye by using water free radical cations

Abstract

The invention discloses a method for degrading dye by using water free radical cations, which comprises the following steps of: directly placing a dye solution below a spray point, coaxially inserting the spray point into a fused quartz capillary tube, and applying high pressure to enable the water dimer free radical cations generated by the reaction of the needle point and water vapor in the air to react with the dye solution, so that the dye solution is degraded. And collecting the degraded dye molecules on the conductive glass, and analyzing and comparing the degraded dye molecules with an original dye solution. According to the method, the water dimer free radical cations and the dye solution are fully reacted by simulating a corona discharge experiment, a precedent for realizing non-targeted degradation of pollutants by using the water dimer free radical cations is created, a new insight is provided for a green degradation process, and the method has important scientific and economic values for exploring environmental pollutant degradation.

Description

Technical Field

[0001] The invention relates to the fields of environmental protection and green degradation, and in particular to a method for degrading dyes by utilizing water free radical cations. Background Art

[0002] Dye degradation technology has always been a key issue in environmental protection. With the rapid development of industrialization in the early 20th century, the discharge of dye wastewater increased dramatically. Traditional physical and chemical treatment methods were unable to effectively remove the complex organic matter in dyes, resulting in severe damage to aquatic ecosystems. Against this backdrop, the academic community proposed the "biodegradation" theory, which posits that the metabolic power of microorganisms can break down dye molecules into harmless small molecules, thereby achieving environmental remediation. Through experiments simulating the microbial communities found in natural water bodies, scientists have successfully screened strains capable of efficiently degrading dyes and revealed their degradation mechanisms, which has advanced the development of biodegradation technology. In recent years, environmental science has gained a deeper understanding of the migration and transformation of dyes in the environment. Research has found that dyes not only undergo degradation reactions within water but can also migrate and spread between different environmental media due to natural factors such as water flow and wind, potentially impacting the broader ecosystem. Advances in modern analytical techniques have also enabled the precise detection of trace amounts of dyes in the environment, providing strong support for a comprehensive understanding of dyes' environmental behavior.

[0003] As the core medium of life, water plays an irreplaceable role in numerous fields, including biochemistry, daily applications, and industrial production. In recent years, research on water has continued to garner widespread attention from the scientific community, with the chemistry of gaseous water radical cations drawing particular attention. This research direction not only offers new perspectives on fundamental scientific questions such as the origin of life, mechanisms of aging, energy conversion, and chemical synthesis, but also opens up important avenues for understanding many key processes in nature. In natural processes, water radical cations play multiple key roles: they participate in proton transfer processes, influence the formation of hydrogen bond networks, are closely related to cellular damage mechanisms, and play a significant role in atmospheric and interstellar chemistry. For this reason, global research on water radical cations has shown a significant growth trend. At the applied research level, water radical cations offer broad application prospects.

[0004] This study designs a novel reactor that simulates the discharge reaction between a needle tip and water vapor in the air, generating water dimer radical cations that then react with a dye solution to produce degraded dye molecules. This research provides new insights into possible pathways to the origin of life. Studying water radical cation reactions based on the synthesis of essential substances required for life has scientific and economic value in exploring the potential of water dimer radical cations generated by environmental corona discharge to degrade various dyes. Summary of the Invention

[0005] The present invention aims to provide a novel reaction for rapidly degrading dyes based on the interaction of water dimer free radical cations with dye solutions. This invention can provide new insights into green degradation research. The technical solutions of the present invention are as follows:

[0006] A method for degrading dyes using water radical cations comprises placing a dye solution directly on conductive glass and below a discharge needle, then coaxially inserting the discharge needle into a fused silica capillary, applying high voltage to the discharge needle so that the tip of the discharge needle reacts with water vapor in the air to produce water dimer radical cations that react with the dye solution to obtain degraded dye molecules, which are then collected on the conductive glass for analysis and comparison with the original dye solution.

[0007] Preferably, the high voltage applied to the discharge needle is 4-5 kV.

[0008] Preferably, the discharge needle and the conductive glass are connected to the positive electrode and the negative electrode of the high voltage source respectively, a reaction space is defined between the discharge needle and the conductive glass, and the air flows through the reaction space.

[0009] Preferably, the discharge needle is made of stainless steel, the outer diameter of the discharge needle is 150 μm, and the curvature radius of the needle tip is about 30 μm.

[0010] Preferably, the analysis and comparison are specifically performed using UV-visible absorption spectroscopy, ESI-MS and tandem MS.

[0011] Preferably, the dye molecule is at least one of a cationic dye, an anionic dye and a neutral dye.

[0012] Preferably, the cationic dye is one of RhB, MG and MV, the anionic dye is MO and / or XO, and the neutral dye is SR.

[0013] It should be noted that: RhB is rhodamine B, MG is malachite green, MV is methyl violet, MO is methyl orange, XO is xylenol orange, and SR is an azo heterocyclic solvent dye.

[0014] The present invention has the beneficial effect of utilizing a discharge reaction to cause air containing water molecules to react with a needle tip to generate water dimer radical cations. The resulting water dimer radical cations then react with a dye solution to degrade it; the degraded dye molecules are then collected on conductive glass. The present invention aims to provide a novel reaction based on the direct interaction of water dimer radical cations with dyes for rapid dye degradation, providing new insights into green degradation research. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 This is a schematic structural diagram of a dye degradation device according to an embodiment of the present invention, wherein 1 is a discharge needle, 2 is a high voltage source, and 3 is a conductive glass;

[0017] Figure 2 Figure 5 is the ESI mass spectra of water dimer radical cation before and after the reaction with Rhodamine B solution, where a1 and a2 are the ESI mass spectra of Rhodamine B solution before and after 10 minutes of degradation, respectively, and b and c are the secondary mass spectra of Rhodamine B degradation;

[0018] Figure 3 These are UV images of water dimer radical cations before and after the reaction with various dye solutions, where a, c, e, g, i, and k are the UV-visible absorption spectra of RhB, MG, MV, MO, XO, and SR aqueous solutions before and within 10 minutes of exposure to water dimer radical cations, respectively; b, d, f, h, j, and l are the conversion rate graphs of RhB, MG, MV, MO, XO, and SR aqueous solutions at different times, respectively.

[0019] Figure 4 The mass spectrum of water dimer radical cation produced by water ionization. DETAILED DESCRIPTION

[0020] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0022] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0024] See also Figure 1-Figure 3 An embodiment of the present invention provides a method for degrading dyes using water radical cations, wherein the method comprises a device for degrading dyes. Figure 1 ), specifically comprising a corona discharge ionization source, a high voltage source 2 and a dye solution.

[0025] The construction of the ion source includes a sharp discharge needle 1 coaxially inserted into a fused silica capillary, and the assembly is firmly fixed with a three-way connector and a silica ferrule.

[0026] The high voltage source supplies direct current.

[0027] The dye solution is placed directly below the discharge needle 1 , and the distance between the surface of the sample solution and the tip of the discharge needle 1 is about 5 mm.

[0028] The ion source comprises a discharge needle 1 and conductive glass 3 positioned relative to each other. The discharge needle 1 and conductive glass 3 are connected to the positive and negative electrodes of a high-voltage source 2, respectively. A reaction space is defined between the discharge needle 1 and conductive glass 3, through which the air flows. Preferably, the voltage of the high-voltage source is 4.5 kV.

[0029] The discharge needle 1 is made of stainless steel, has an outer diameter of 150 μm, and a curvature radius of the needle tip of about 30 μm.

[0030] Based on the above device, the dye degradation method includes:

[0031] Turning on the high voltage source 2 and applying a high voltage to the discharge needle 1, so that the tip of the discharge needle 1 generates a corona discharge and ionizes water vapor in the surrounding air to form water dimer radical cations. The formed water dimer radical cations react with the dye solution to degrade it;

[0032] The degraded dye molecules are collected on the conductive glass 3. Specifically, a high voltage (4.5 kV) is applied to the discharge needle 1, generating a corona discharge at the tip of the discharge needle 1. At room temperature and pressure (e.g., 25°C, 1 atmosphere), water vapor in the air generates water dimer radical ions through the high-voltage corona discharge. The water dimer radical ions fully contact and react with the dye solution, degrading it. The degraded dye molecules are collected on the conductive glass 3, and then the degradation products are compared with the original dye solution for analysis. Specifically, UV-visible absorption spectroscopy, ESI-MS, and tandem MS are used for analysis and detection.

[0033] The following are some examples to verify the degradation results of the above dye degradation method:

[0034] Example 1

[0035] At room temperature and pressure, humid water vapor in the air moves toward the needle tip area. A high voltage (4.5kV) is applied to the discharge needle. The needle tip reacts with the water vapor to generate water dimer radical cations. The formed water dimer radical cations then react with rhodamine B (RhB) solution for 2 minutes, and the degraded dye molecules are collected on conductive glass.

[0036] Example 2

[0037] At room temperature and pressure, humid water vapor in the air moves toward the needle tip area. A high voltage (4.5kV) is applied to the discharge needle. The needle tip reacts with the water vapor to generate water dimer radical cations. The formed water dimer radical cations then react with rhodamine B (RhB) solution for 6 minutes, and the degraded dye molecules are collected on conductive glass.

[0038] Example 3

[0039] At room temperature and pressure, humid water vapor in the air moves toward the needle tip area. A high voltage (4.5kV) is applied to the discharge needle, and the needle tip reacts with the water vapor to generate water dimer radical cations. The formed water dimer radical cations then react with rhodamine B (RhB) solution for 10 minutes, and the degraded dye molecules are collected on conductive glass.

[0040] Test 1: After ionizing the aqueous solution using a low-energy atmospheric pressure corona discharge device, the ionized product was introduced into the mass spectrometer inlet, and the characteristic ion m / z 36 ( Figure 4 ), which was confirmed by tandem mass spectrometry and high-resolution mass spectrometry to be a water dimer radical cation ((H2O)2 +· The results showed that water dimer radical cations were generated when water was ionized using this device.

[0041] Test 2: Mass spectrometry analysis was performed on the Rhodamine B solution before and after degradation in Example 3. From the mass spectrometry data, before degradation, a characteristic ion m / z 443 was detected in the positive ion mode with a signal intensity of about 7.8×106 ( Figure 2 However, after degradation, m / z 443 was barely detectable ( Figure 2 a2 in the middle), indicating that RhB was significantly degraded within about 10 minutes. In addition, significant degradation products were observed at m / z 227 and m / z 339, with base peak intensities of approximately 8.1×104 (lower Figure 2The degradation products m / z 227 and m / z 339 were attributed to the oxidation reaction between the water dimer radical cation and the rhodamine B molecule, characterized by dephenylation and hydroxylation, as well as sequential N-deethylation. Similar degradation products were detected by ESI-MS analysis when RhB was dissolved in D2O, and consistent losses were observed in tandem MS experiments ( Figure 2 (bc).

[0042] Test 3: Using a low-energy atmospheric pressure corona discharge device at a discharge voltage of 4.5kV, RhB, MG, MV, MO, XO, and SR solutions were degraded. The three-dimensional mobile platform adjusted the needle tip focus to always remain 2mm above the solution surface. The sample preparation degradation time was 0min, 2min, 4min, 6min, 8min, and 10min. The concentrations of RhB, MG, MV, MO, XO, and SR after degradation were obtained every two minutes and detected by UV-visible spectrophotometry. The results showed that these dyes were effectively decomposed by water dimer free radical cations. The results are shown in Figure 3. Figure 3 Zhongal.

[0043] In summary, according to the dye degradation method proposed in this embodiment, the entire degradation process can be carried out at room temperature and pressure (referring to pressure), without the need for chemical catalysts, saving energy, and being green and pollution-free.

[0044] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0045] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for degrading dyes using water radical cations, characterized in that: The dye solution is placed directly on the conductive glass and located below the discharge needle. The discharge needle is then coaxially inserted into a fused silica capillary. By applying high voltage to the discharge needle, the tip of the discharge needle reacts with water vapor in the air to produce water dimer radical cations that react with the dye solution to obtain degraded dye molecules. The degraded dye molecules are then collected on the conductive glass and analyzed and compared with the original dye solution.

2. The method for degrading dyes by utilizing water radical cations according to claim 1, wherein: The high voltage applied to the discharge needle is 4-5 kV.

3. The method for degrading dyes by utilizing water radical cations according to claim 1, wherein: The discharge needle and the conductive glass are connected to the positive electrode and the negative electrode of the high voltage source respectively. A reaction space is defined between the discharge needle and the conductive glass, and the air flows through the reaction space.

4. The method for degrading dyes by utilizing water radical cations according to claim 1, wherein: The discharge needle is made of stainless steel, has an outer diameter of 150 μm, and a curvature radius of the needle tip is about 30 μm.

5. The method for degrading dyes by utilizing water radical cations according to claim 1, characterized in that: The analysis and comparison were carried out using UV-visible absorption spectroscopy, ESI-MS and tandem MS.

6. The method for degrading dyes by utilizing water radical cations according to claim 1, characterized in that: The dye molecule is at least one of a cationic dye, an anionic dye and a neutral dye.

7. The method for degrading dyes by utilizing water radical cations according to claim 6, characterized in that: The cationic dye is one of RhB, MG and MV, the anionic dye is MO and / or XO, and the neutral dye is SR.

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