WO2024130730A1 - Method and device capable of continuously generating hydroxyl radicals, and use - Google Patents

Abstract

A method and device capable of continuously generating hydroxyl radicals, and the use. The method comprises: adding epigallocatechin-3-gallate into an aqueous solution and mixing same uniformly, so as to obtain an epigallocatechin-3-gallate aqueous solution (A); and illuminating the epigallocatechin-3-gallate aqueous solution under a light source, so as to continuously generate hydroxyl radicals by means of a photochemical reaction (B). The method is simple, feasible, easy to control, economically practical, environmentally friendly and safe, and can be widely applied to the fields of sterilization and disinfection, degradation of organic pollutants, etc.

Description

Method, device and application for sustainable generation of hydroxyl radicals Technical Field

The present disclosure relates to the field of photochemical reactions of organic compounds, and in particular to a method, device and application for sustainably generating hydroxyl radicals.

Background technique

Hydroxyl free radicals are extremely active oxidants and are very important in chemistry, biomedicine, and environmental science. In atmospheric chemistry, hydroxyl free radicals are called "cleaners" of the atmosphere because they can effectively oxidize and destroy organic pollutants. In water and air pollution control, advanced oxidation processes based on hydroxyl free radicals have been widely used in the treatment and degradation of organic pollutants in wastewater and waste gas. In addition, in biomedicine, hydroxyl free radicals are considered to be the most reactive and harmful free radicals among the so-called active oxygen species, which can cause oxidative damage to DNA, proteins, and lipids; hydroxyl free radicals have a strong oxidizing effect on pathogens, and the sterilization rate of 300μmol/L hydroxyl free radicals reaches 99%. Therefore, hydroxyl free radicals are also used as disinfectants in the sterilization and disinfection process of public health.

At present, the most widely accepted mechanism for the generation of hydroxyl radicals is the generation of hydroxyl radicals through the Fenton reaction catalyzed by transition metals; and the generation of hydroxyl radicals through the Fenton-like reaction of hydrogen peroxide (H ₂ O ₂ ) and haloquinone without the participation of metal ions. The H ₂ O ₂ , haloquinone, and transition metal added in these reactions to generate hydroxyl radicals are all toxic and harmful to the human body and the environment. Therefore, a more efficient, simple and safe method to generate hydroxyl radicals is urgently needed.

Summary of the invention

In view of this, the main purpose of the present disclosure is to provide a method, device and application for sustainably generating hydroxyl radicals, in order to at least partially solve at least one of the above-mentioned technical problems.

To achieve the above purpose, the technical solution of the present disclosure is as follows:

As a first aspect of the present disclosure, a method for sustainably generating hydroxyl radicals is provided, comprising:

Epigallocatechin-3-gallate (EGCG) is added to the aqueous solution and mixed evenly to obtain an EGCG aqueous solution;

The EGCG aqueous solution is placed under a light source and irradiated to continuously generate hydroxyl free radicals through photochemical reaction.

As a second aspect of the present disclosure, a device for implementing the above-mentioned method for sustainably generating hydroxyl radicals is provided, the device comprising:

The liquid-filling device is made of light-proof material and is suitable for containing EGCG aqueous solution;

The illumination device includes a light source, which is suitable for illuminating the EGCG aqueous solution so that the EGCG aqueous solution continuously produces hydroxyl free radicals.

As a third aspect of the present disclosure, there is provided an application of the above-mentioned method for sustainably generating hydroxyl radicals in the process of sterilization or degradation of organic pollutants.

Based on the above technical solution, the present disclosure provides a method, device and application for sustainably generating hydroxyl radicals, which includes at least one or part of the following technical effects:

The present disclosure provides a method for sustainably generating hydroxyl radicals, wherein EGCG is dissolved in an aqueous solution and irradiated with light to continuously generate a large number of hydroxyl radicals through a photochemical reaction. The method is simple, feasible, easy to control, economical, practical, green and safe, and can be widely used in the fields of sterilization and disinfection, and degradation of organic pollutants.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for sustainably generating hydroxyl radicals according to an embodiment of the present disclosure;

FIG2 is a signal diagram of hydroxyl radical generation in Example 1, Comparative Example 1 and Comparative Example 2 of the present disclosure;

FIG3 is a graph showing the generation of hydroxyl radicals in Example 1, Comparative Example 3 and Comparative Example 4 of the present disclosure;

FIG4 is a diagram showing the dynamic change of the amount of hydroxyl radical generated as the illumination time changes in Example 2 of the present disclosure and a generation formula of hydroxyl radicals;

FIG5 is a graph showing the hydroxyl radical generation content of the EGCG aqueous solution of Example 3 of the present disclosure under illumination conditions of light sources of different intensities (50 mW/cm ² to 300 mW/cm ² );

FIG6 is a schematic diagram of a device for sustainably generating hydroxyl radicals according to Example 4 of the present disclosure.

In the above drawings, the meanings of the reference numerals are as follows:

1. Liquid filling pot; 2. Pot handle; 3. Atomizing nozzle; 4. Light source; 5. Switch button; 6. Light intensity adjustment button.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

In the process of realizing the present disclosure, it was found that how to avoid harm to the human body and the environment during the generation of hydroxyl radicals is a technical difficulty in efficiently generating hydroxyl radicals. The present disclosure adds EGCG to an aqueous solution, mixes it evenly to form an EGCG aqueous solution, places it under a light source, and illuminates it. It is found that a large amount of hydroxyl radicals can be continuously generated, and the green production of hydroxyl radicals is achieved while achieving efficient generation of hydroxyl radicals.

Specifically, according to an embodiment of the present disclosure, a method for continuously generating hydroxyl radicals is provided. FIG1 is a flow chart of a method for continuously generating hydroxyl radicals according to an embodiment of the present disclosure.

As shown in FIG1 , the method for continuously generating hydroxyl radicals in this embodiment includes steps A to B:

Step A: adding EGCG to the aqueous solution and mixing evenly to obtain an EGCG aqueous solution;

Step B: placing the EGCG aqueous solution under a light source for illumination to continuously generate hydroxyl radicals through photochemical reaction.

According to the embodiments of the present disclosure, EGCG is widely present in tea, fruits and vegetables, and is often used as an additive in processed foods, health products and clinical drugs due to its antioxidant and possible anti-cancer activity. Therefore, EGCG has the advantages of being green, safe, biodegradable, easily available in nature and existing in large quantities. In the process of realizing the present disclosure, it was found that the photochemical reaction of EGCG aqueous solution to produce hydroxyl radicals has a significant competitive advantage compared to the reaction of scavenging hydroxyl radicals based on its own antioxidant properties, providing favorable conditions for its sustainable production of a large number of hydroxyl radicals.

According to the embodiments of the present disclosure, the EGCG aqueous solution is placed under a light source for illumination, and a large number of hydroxyl radicals are continuously generated through photochemical reactions. The amount of free radicals generated in a 2g/L EGCG aqueous solution is equivalent to the amount of hydroxyl radicals generated by 0.075g/L _H2O2 under the same illumination conditions; the duration of the generation of hydroxyl radicals is as _long as more than 12 hours, without the presence of metal ions and hydrogen peroxide, and without the participation of biological systems such as cells. The method provided by the present disclosure has the advantages of being green, safe, simple, feasible, easy to control, and economical and practical.

According to an embodiment of the present disclosure, the method of uniform mixing may include but is not limited to vortexing, mechanical stirring, manual stirring, etc.

According to the embodiments of the present disclosure, the generated free radicals can be confirmed to be hydroxyl free radicals by existing technical methods, specifically including:

The electron paramagnetic resonance spectrometer with free radical spin trapping technology detected that the hyperfine splitting constant value of the spin trap DMPO and hydroxyl radical adduct (DMPO-·OH) is: α ^N = α ^H = 14.8G;

The generated free radicals were further confirmed to be hydroxyl radicals by electron paramagnetic resonance secondary spin trapping method.

According to an embodiment of the present disclosure, in a method for sustainably generating hydroxyl radicals provided by the present disclosure, the aqueous solution includes any one of tap water, distilled water, and ultrapure water; the mass concentration of EGCG in the EGCG aqueous solution is 2 to 100 g/L.

According to the embodiments of the present disclosure, hydroxyl radicals can be continuously generated under light conditions when the mass concentration of EGCG is in the range of 2 to 100 g/L.

According to an embodiment of the present disclosure, the light source includes a sunlight light source or an ultraviolet light source.

According to the embodiments of the present disclosure, the sunlight light source may be a natural light source or may be simulated by a full-band xenon lamp, and the ultraviolet light source may be simulated by a mercury lamp or an ultraviolet lamp whose energy is concentrated in the ultraviolet region.

According to the embodiments of the present disclosure, the illumination wavelength of the sunlight light source is 300-1000 nm; the illumination wavelength of the ultraviolet light source is 10-400 nm.

According to the embodiments of the present disclosure, the illumination wavelength of the sunlight light source simulated by a full-band xenon lamp is 300-1000nm, the illumination wavelength of the ultraviolet light source simulated by a mercury lamp with energy concentrated in the ultraviolet light region is 200-400nm, and the illumination wavelength of the ultraviolet light source simulated by an ultraviolet lamp with energy concentrated in the ultraviolet light region is 10-400nm.

According to the embodiment of the present disclosure, the illumination time is 0 to 200 minutes; and the illumination intensity is 50 to 300 mW/cm ² .

According to the embodiments of the present disclosure, hydroxyl radicals can be continuously generated by irradiating an aqueous solution with a mass concentration of EGCG of 2 to 100 g/L within 0 to 200 minutes of light exposure.

According to an embodiment of the present disclosure, placing the EGCG aqueous solution under a light source for illumination comprises:

The EGCG aqueous solution is sprayed in an atomized form to form atomized water droplets; and the atomized water droplets are illuminated by a light source.

According to the embodiments of the present disclosure, hydroxyl radicals are generated by atomization, which can improve the effective contact between hydroxyl radicals and the object to be treated in treatment scenarios such as sterilization or pollution degradation, thereby improving the treatment effect.

According to an embodiment of the present disclosure, there is also provided a device for implementing the above-mentioned method for sustainably generating hydroxyl radicals, comprising:

A liquid-filling device, which is made of light-proof material and is suitable for containing EGCG aqueous solution;

The illumination device comprises a light source, and the light source is suitable for illuminating the EGCG aqueous solution so as to enable the EGCG aqueous solution to continuously generate hydroxyl free radicals.

According to an embodiment of the present disclosure, the device for sustainably generating hydroxyl radicals further comprises:

an atomizing device, the atomizing device being adapted to spray the EGCG aqueous solution in the liquid-containing device in an atomized form to form atomized water droplets;

Wherein, the light source is suitable for illuminating the atomized water droplets;

According to an embodiment of the present disclosure, the light source may include but is not limited to a xenon lamp, a mercury lamp, an ultraviolet lamp, etc.

According to an embodiment of the present disclosure, there is also provided an application of the above-mentioned method for sustainably generating hydroxyl radicals in the process of sterilization or degradation of organic pollutants.

The technical solution of the present disclosure is further described below by means of specific embodiments in combination with the accompanying drawings. It should be noted that the following specific embodiments are only used as examples, and the protection scope of the present disclosure is not limited thereto. The materials, reagents, etc. used in the embodiments of the present disclosure, unless otherwise specified, can be obtained from commercial channels.

Embodiment 1:

Weigh 1 g of EGCG, add it to 500 mL of pure water, and vortex mix it evenly to prepare a 2 g/L EGCG aqueous solution; place the 2 g/L EGCG aqueous solution under a xenon lamp with a light intensity of 100 mW/ ^cm2 for illumination.

Comparative Example 1

The operation is similar to that of Example 1, except that EGCG is not contained.

Comparative Example 2

The operation is similar to that of Example 1, except that there is no illumination condition.

Electron paramagnetic resonance (EPR) spin trapping technology was used to detect the hydroxyl radicals generated under the system conditions of Example 1, Comparative Example 1 and Comparative Example 2 by adding a spin trapping agent (DMPO), and Bruker’s Xenon software was used to deconvolute the EPR spectra and perform spectrum fitting.

FIG2 is a signal diagram of hydroxyl radical generation in Example 1, Comparative Example 1 and Comparative Example 2 of the present disclosure.

As shown in Figure 2, the EGCG aqueous solution of Example 1 showed characteristic peaks of hydroxyl radicals under illumination (the ratio of peaks from left to right was 1:2:2:1), and the hyperfine splitting constant value of the generated hydroxyl radical and DMPO adduct (DMPO-·OH) was: α ^N = α ^H = 14.8G (DMPO-·OH literature data α ^N = α ^H = 14.9G), and the experimental value was consistent with the value reported in the literature. This shows that the EGCG aqueous solution can produce hydroxyl radicals under illumination, while the comparative examples 1 and 2 did not show characteristic peaks of hydroxyl radicals, indicating that hydroxyl radicals can only be produced under the conditions of both EGCG aqueous solution and illumination. Among them, the final concentration of DMPO was 120mmol/L, and the electron paramagnetic resonance parameters were set as follows: microwave frequency, 9.78GHz; modulation frequency, 100kHz; modulation amplitude, 1.0G; receiver gain, 10dB; central field, 3505G; scan width, 100G; time constant, 81.92ms; scan time, 50s; and microwave power, 20mW.

Among them, taking the generation conditions of the electron paramagnetic resonance spin capture test embodiment 1 as an example, the specific operation is: using DMPO as a spin capture agent, adding 2μL 3mol/L DMPO to 20μL 2g/L EGCG aqueous solution, using buffer PBS to make the volume to 50μL, and using a vortex to mix the solution evenly. The mixed solution is transferred to an EPR quartz capillary (inner diameter ~1mm, outer diameter ~1.55mm) and sealed with a sealant at one end, the capillary is inserted into a 4mm quartz capillary, and then placed in the EPR resonant cavity for electron paramagnetic resonance detection.

Since there is ion interference when the EPR spin trapping technology detects whether the free radical is a hydroxyl radical, in order to further prove that the free radical generated by the method provided by the present invention is a hydroxyl radical, it is further proved by the electron paramagnetic resonance secondary spin trapping method.

Comparative Example 3

The operation is similar to that of Example 1, except that 5% by volume of a hydroxyl radical scavenger (DMSO) is added to the EGCG aqueous solution.

Comparative Example 4

The operation was similar to that of Example 1, except that EGCG was not contained and pure water was replaced by DMSO.

The hydroxyl radicals generated under the system conditions of Example 1, Comparative Example 3 and Comparative Example 4 were detected by electron paramagnetic resonance secondary spin capture method.

FIG3 is a graph showing the generation of hydroxyl radicals in Example 1, Comparative Example 3 and Comparative Example 4 of the present disclosure.

As shown in Figure 3, after adding 5% by volume of DMSO in Comparative Example 3, the generation of hydroxyl radicals decreased by 68%, providing conclusive evidence that the EGCG aqueous solution can generate hydroxyl radicals under light conditions, and further proving that the free radicals generated by the EGCG aqueous solution under light conditions are hydroxyl radicals.

The calculation formula of the amount of hydroxyl radical generated is shown in formula (1-1):

C＝M÷ _CE (1-1)

C: the amount of hydroxyl radicals generated per gram of EGCG, mol/g;

M: absolute amount of hydroxyl radicals, mol/L;

_CE : Concentration of EGCG in EGCG aqueous solution, g/L.

M was obtained by quantitative analysis of hydroxyl radicals using Bruker’s Xenon software;

_CE was obtained by EPR detection.

Example 2

The operation was similar to that of Example 1, except that the illumination time was changed to analyze the effect of illumination time on the generation of hydroxyl radicals in the EGCG aqueous solution.

FIG4 is a diagram showing the dynamic changes in the amount of hydroxyl radical generated as the illumination time changes in Example 2 of the present disclosure and a generation formula for hydroxyl radicals.

As shown in Figure 4, under the irradiation condition of 100mW/ ^cm2 xenon lamp, a large number of hydroxyl radicals are immediately generated in the EGCG aqueous solution. The generation formula of the reaction process is also marked in Figure 4. In addition, the generation of hydroxyl radicals reaches the highest when the illumination time is 350 seconds, and 5.6μmol of hydroxyl radicals are generated per gram of EGCG, and the presence of hydroxyl radicals can be detected for at least 200 minutes; in addition, when the light source is turned off, the content of hydroxyl radicals in the EGCG aqueous solution quickly decreases to zero, indicating that hydroxyl radicals are continuously generated by the EGCG aqueous solution under illumination conditions. It has been verified that the EGCG aqueous solution can continuously generate hydroxyl radicals under continuous illumination for at least 200 minutes.

Example 3

The operation was similar to that of Example 1, except that the light intensity was changed to analyze the effect of light intensity on the generation of hydroxyl radicals in the EGCG aqueous solution.

FIG5 is a graph showing the amount of hydroxyl radicals generated by the EGCG aqueous solution of Example 3 of the present disclosure under different light intensity conditions (50 mW/cm ² to 300 mW/cm ² ).

As shown in FIG. 5 , as the light intensity increases, the amount of hydroxyl radicals generated in the EGCG aqueous solution also increases significantly, indicating that within the light intensity range set in the embodiment of the present disclosure, the increase in light intensity plays a positive role in the amount of hydroxyl radicals generated in the EGCG aqueous solution.

Example 4

Specifically, this embodiment provides a device that can sustainably generate hydroxyl radicals, which is a spray bottle; the liquid filling device is a liquid filling pot, which is made of light-proof material; the illumination device includes a light source 4 (xenon lamp, mercury lamp, ultraviolet lamp, etc.), a switch button and a light intensity adjustment button; and the atomization device includes an atomization nozzle and a liquid transmission tube.

FIG6 is a schematic diagram of a device for sustainably generating hydroxyl radicals according to an embodiment of the present disclosure.

More specifically, as shown in FIG6 , the device for sustainably generating hydroxyl radicals comprises a liquid-filled pot 1 , a pot handle 2 , an atomizing nozzle 3 , a light source 4 , a switch button 5 , and a light intensity adjustment button 6 .

The specific operation is to add EGCG and pure water into the liquid pot 1, vortex mix evenly, press the pot handle 2 to make the internal pressure of the liquid pot higher than the external pressure, so that the EGCG aqueous solution placed in the liquid pot 1 is sprayed out through the liquid transmission tube through the atomizing nozzle 3, and the atomized water droplets containing EGCG immediately generate a large number of hydroxyl radicals under the irradiation of the light source 4. The hydroxyl radical generation process can be stopped by turning off the light source 4 by adjusting the switch button 5, and the light intensity can be adjusted by adjusting the light adjustment button 6 of the light source 4 to adjust the amount of hydroxyl radicals generated. The above-mentioned device for continuously generating hydroxyl radicals can be used in the sterilization and disinfection of some indoor and outdoor air, tap water and other scenes and the degradation of organic pollutants.

The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims (10)

A method for sustainably generating hydroxyl radicals comprising: adding epigallocatechin-3-gallate to the aqueous solution and mixing evenly to obtain an epigallocatechin-3-gallate aqueous solution; The epigallocatechin-3-gallate aqueous solution is placed under a light source for illumination to continuously generate hydroxyl radicals through a photochemical reaction. The method according to claim 1, wherein the aqueous solution comprises any one of tap water, distilled water, and ultrapure water; and the mass concentration of epigallocatechin-3-gallate in the epigallocatechin-3-gallate aqueous solution is 2 to 100 g/L. The method according to claim 1, wherein the light source comprises a sunlight light source or an ultraviolet light source. The method according to claim 3, wherein the illumination wavelength of the sunlight light source is 300 to 1000 nm; the illumination wavelength of the ultraviolet light source is 10 to 400 nm. The method according to claim 1, characterized in that the illumination time is 0 to 200 minutes; and the illumination intensity is 50 to 300 mW/cm ² . The method according to claim 1, wherein placing the epigallocatechin-3-gallate aqueous solution under a light source for illumination comprises: spraying the epigallocatechin-3-gallate aqueous solution in an atomized form to form atomized water droplets; The light source is used to illuminate the atomized water droplets. A device capable of sustainably generating hydroxyl radicals, wherein the device is used to implement the method according to any one of claims 1 to 6, and comprises: A liquid-filling device, the liquid-filling device is made of a light-proof material and is suitable for containing the epigallocatechin-3-gallate aqueous solution; The illumination device comprises a light source, wherein the light source is suitable for irradiating the epigallocatechin-3-gallate aqueous solution so as to enable the epigallocatechin-3-gallate aqueous solution to continuously generate hydroxyl free radicals. The device according to claim 7, wherein the device further comprises: an atomizing device, wherein the atomizing device is adapted to spray the epigallocatechin-3-gallate aqueous solution in the liquid-filling device in an atomized form to form atomized water droplets; Wherein, the light source is suitable for illuminating the atomized water droplets; The device according to claim 7, wherein the light source comprises any one of a xenon lamp, a mercury lamp, and an ultraviolet lamp. An application of the method as claimed in any one of claims 1 to 6 in the process of sterilization or degradation of organic pollutants.

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