Method and apparatus for producing nanobubbles

Abstract

The application discloses a method and device for preparing nanometer bubbles, and the method comprises the following steps: adding a semiconductor and a liquid into a container, wherein the liquid submerges at least a part of the semiconductor; introducing a gas into the liquid; and irradiating the semiconductor and the liquid by using a light source. The application can prepare small and uniform nanometer bubbles which can stably exist in a solution, the particle size of the nanometer bubbles is basically concentrated in 2nm-15nm, the specific surface area of the nanometer bubbles is greatly improved, and the treatment effect of the nanometer bubble solution is improved. Meanwhile, the obtained nanometer bubble solution can be kept for more than one month, and the storage time is relatively long.

Description

Technical Field

[0001] This invention relates to the field of materials preparation technology, and specifically to a method and apparatus for preparing nanobubbles. Background Technology

[0002] Nanobubbles are mainly classified into surface nanobubbles, bulk nanobubbles, and nanobubbles in solids. Among them, bulk nanobubbles are nanobubbles generated in the liquid phase. Due to their high mass transfer efficiency, large specific surface area, and high surface zeta potential, they are widely used in flotation recovery, food processing, new energy, and other fields. By definition, microbubbles have a diameter of 10 μm to 100 μm, nanobubbles have a diameter of less than 1 μm, and micro-nanobubbles are bubbles with a particle size between microbubbles and nanobubbles.

[0003] Typically, the gas chosen for preparing nanobubbles is a relatively stable gas that does not react with water. Current nanobubble production methods and equipment suffer from drawbacks such as complex operation, high energy consumption, significant time costs, and insufficient bubble uniformity and stability. For example, some existing methods require a two-stage process to prepare nanobubbles, which increases production costs. Furthermore, different application areas require different numbers / concentrations of nanobubbles. Currently, there are no solutions to these problems. Summary of the Invention

[0004] In view of the problems existing in the prior art, in a first aspect, the present invention aims to provide a method for preparing nanobubbles. In a second aspect, the present invention aims to provide a liquid containing nanobubbles. In a third aspect, the present invention aims to provide an apparatus for preparing nanobubbles.

[0005] The purpose of this invention is to provide a method for enhancing the preparation of controllable number / concentration nanobubbles by exciting semiconductor photogenerated electrons and holes using ultraviolet-visible light. Compared with electrochemical methods, solution replacement methods, decompression methods, cavitation methods, etc., the method of this invention has the advantages of controllable number / concentration of nanobubbles, controllable gas source, simple equipment, easy operation, low time cost, and low energy consumption, and can ultimately obtain a nanobubble solution with small and uniform bubbles.

[0006] In view of the problems existing in the prior art, the method of the present invention unexpectedly solves the above problems by generating gas nuclei through photogenerated electron-hole generation.

[0007] In view of the problems existing in the prior art, the method and apparatus of the present invention only need to control the wavelength of light or the illumination time to achieve the purpose of controlling the number or concentration of nanobubbles.

[0008] The present invention adopts the following technical solution:

[0009] In a first aspect, this application provides a method for preparing nanobubbles, comprising:

[0010] A semiconductor and a liquid are added to a container, wherein the liquid immerses at least a portion of the semiconductor;

[0011] Gas is introduced into the liquid;

[0012] The semiconductor and the liquid are illuminated with a light source.

[0013] For illustrative purposes and not for limitation, in some embodiments, semiconductor (particles) and liquid are simultaneously added to a container, and mechanical stirring is activated to uniformly distribute the semiconductor particles in the solution. Gas is introduced into the container until the gas in the solution is saturated or supersaturated. A light source is then turned on. Under illumination, the semiconductor particles are photoexcited, generating photogenerated electrons and holes. These electrons and holes reach the surface of the semiconductor particles and transfer electrons with the solute in the solution, creating gas nuclei. The gas in the solution enters a higher supersaturation state, continuously forming gas nuclei. Simultaneously, the shear force of the stirring process helps bubbles detach from the semiconductor surface and enter the bulk solution, thereby generating smaller and more uniform nanobubbles. The wavelength of the light source and the irradiation time can be controlled by a controller.

[0014] In conjunction with the first aspect, in some feasible embodiments, the semiconductor includes at least one of a P-type semiconductor, an N-type semiconductor, a semiconductor having a PN junction, a semiconductor with a doped single-crystal silicon PN junction, a semiconductor with a doped polycrystalline silicon PN junction, a copper indium gallium selenide semiconductor, and a perovskite semiconductor.

[0015] In conjunction with the first aspect, in some feasible implementations, the semiconductor is a nanoparticle semiconductor.

[0016] In conjunction with the first aspect, in some feasible embodiments, the semiconductor includes at least one selected from NiO (3.5 eV), MnO (3.6 eV), PbO (2.8 eV), Pr2O3 (3.9 eV), TiO2 (3.2 eV), ZnO (3.2 eV), CdS (2.4 eV), GaP (2.3 eV), Fe2O3 (2.3 eV), CdSe (1.7 eV), Ag2S (0.92 eV), FeS2 (0.95 eV), PdO (1.0 eV), and MnO2 (0.25 eV).

[0017] In conjunction with the first aspect, in some feasible embodiments, the semiconductor includes at least one of TiO2, ZnO, CdS, GaP, Fe2O3, Ag2S, FeS, FeS2, PdO, MnO2, a semiconductor with a doped single-crystal silicon PN junction, a semiconductor with a doped polycrystalline silicon PN junction, a copper indium gallium selenide semiconductor, and a perovskite semiconductor. Because these semiconductors have relatively narrow band gaps, electrons can be excited using visible light.

[0018] In conjunction with the first aspect, in some feasible implementations, the wavelength of the light source is ≤740nm, for example, ≤730nm, ≤720nm, ≤710nm, ≤700nm, ≤690nm, ≤680nm, ≤670nm, ≤660nm, ≤650nm, ≤640nm, ≤630nm, ≤620nm, ≤610nm, ≤600nm, ≤590nm, ≤580nm, ≤570nm. nm, ≤560nm, ≤550nm, ≤540nm, ≤530nm, ≤520nm, ≤510nm, ≤500nm, ≤490nm, ≤480nm, ≤470nm, ≤460nm, ≤450nm, ≤440nm, ≤430nm, ≤420nm, ≤410nm, ≤400nm, etc., but not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0019] In conjunction with the first aspect, in some feasible implementations, the wavelength of the light source is <400nm, for example, <390nm, <380nm, <370nm, <360nm, <350nm, <340nm, <330nm, <320nm, <310nm, <300nm, <290nm, <280nm, <270nm, <260nm, <250nm, <240nm, <230nm, <220nm, <210nm, <200nm, etc., but is not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0020] In conjunction with the first aspect, in some feasible implementations, the wavelength of the light source is greater than or equal to 400 nm and less than or equal to 740 nm. For example, the wavelength of the light source is greater than or equal to 410 nm and less than or equal to 730 nm, greater than or equal to 420 nm and less than or equal to 720 nm, greater than or equal to 430 nm and less than or equal to 710 nm, greater than or equal to 440 nm and less than or equal to 700 nm, greater than or equal to 450 nm and less than or equal to 690 nm, greater than or equal to 460 nm and less than or equal to 680 nm, greater than or equal to 470 nm and less than or equal to 740 nm. The ranges are 670nm and above, 480nm and below, 490nm and below, 500nm and below, 640nm and above, 510nm and below, 630nm and above, 520nm and below, 620nm and above, 530nm and below, 610nm and above, 540nm and below, and 600nm and above, etc., but are not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0021] In conjunction with the first aspect, in some feasible implementations, the light emitted by the light source is visible light.

[0022] In conjunction with the first aspect, in some feasible implementations, the light emitted by the light source is ultraviolet light.

[0023] In conjunction with the first aspect, in some feasible implementations, the energy of the light emitted by the light source is ≥1.63 eV, for example, the energy of the light emitted by the light source is ≥1.64 eV, ≥1.65 eV, ≥1.66 eV, ≥1.67 eV, ≥1.68 eV, ≥1.69 eV, ≥1.70 eV, ≥1.71 eV, ≥1.72 eV, ≥1.73 eV, ≥1.74 eV, ≥1.75 eV, ≥1.76 eV, ≥1.77 eV, ≥1.78 eV, ≥1.79 eV, ≥1.80 eV, ≥1.81 eV, ≥1.82 eV, ≥1.83 eV, ≥1.84 eV, ≥1.85 eV. ≥1.86eV, ≥1.87eV, ≥1.88eV, ≥1.89eV, ≥1.90eV, ≥1.91eV, ≥1.92eV, ≥1.93eV, ≥1.94eV, ≥1.95eV, ≥1.96eV, ≥1.97eV, ≥1.98eV, ≥1.99eV, ≥2.0eV, ≥2.1eV, ≥2.2eV, ≥2.3eV, ≥2.4eV, ≥2.5eV, ≥2.6eV, ≥2.7eV, ≥2.8eV, ≥2.9eV, ≥3.0eV, etc., but not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0024] In conjunction with the first aspect, in some feasible implementations, the energy of the light emitted by the light source is from 1.63 eV to 3.1 eV, for example, the energy of the light emitted by the light source is from 1.73 eV to 3.0 eV, 1.83 eV to 2.9 eV, 1.93 eV to 2.9 eV, 2.03 eV to 2.8 eV, 2.13 eV to 2.7 eV, 2.23 eV to 2.6 eV, 2.33 eV to 2.5 eV, etc., but is not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0025] In conjunction with the first aspect, in some feasible implementations, the energy of the light emitted by the light source is >3.1 eV, for example, >3.2 eV, >3.3 eV, >3.4 eV, >3.5 eV, >3.6 eV, >3.7 eV, >3.8 eV, >3.9 eV, >4.0 eV, etc., but not limited to the listed ranges, other unlisted values ​​or ranges within this range also apply.

[0026] In conjunction with the first aspect, in some feasible implementations, the light source includes at least one of a diode, a tungsten filament lamp, and a fluorescent lamp.

[0027] The light source can be located inside or outside the container. The light source includes a light-emitting device and a controller. The controller can control the light-emitting time and wavelength of the light-emitting device.

[0028] In conjunction with the first aspect, in some feasible implementations, the irradiation duration of the light source is at least 1 minute, for example at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 11 minutes, at least 12 minutes, at least 13 minutes, at least 14 minutes, at least 15 minutes, at least 16 minutes, at least 17 minutes, at least 18 minutes, at least 19 minutes, at least 20 minutes, at least 21 minutes, at least 22 minutes, at least 23 minutes, at least 24 minutes, at least 25 minutes, at least 26 minutes, at least 27 minutes, at least 28 minutes, at least 29 minutes, at least 30 minutes, at least 31 minutes, at least 32 minutes, at least 33 minutes, or at least 34 minutes. The ranges are: at least 35 minutes, at least 36 minutes, at least 37 minutes, at least 38 minutes, at least 39 minutes, at least 40 minutes, at least 41 minutes, at least 42 minutes, at least 43 minutes, at least 44 minutes, at least 45 minutes, at least 46 minutes, at least 47 minutes, at least 48 minutes, at least 49 minutes, at least 50 minutes, at least 51 minutes, at least 52 minutes, at least 53 minutes, at least 54 minutes, at least 55 minutes, at least 56 minutes, at least 57 minutes, at least 58 minutes, at least 59 minutes, at least 60 minutes, at least 70 minutes, at least 80 minutes, at least 90 minutes, at least 100 minutes, at least 110 minutes, etc., but are not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0029] In conjunction with the first aspect, in some feasible implementations, the irradiation duration of the light source is from 1 min to 120 min, such as 2 min to 110 min, 5 min to 100 min, 10 min to 90 min, 20 min to 80 min, 30 min to 70 min, 40 min to 60 min, etc., but is not limited to the listed ranges. Other unlisted values ​​or ranges within this range are also applicable.

[0030] In conjunction with the first aspect, in some feasible implementations, the irradiation time of the light source is from 1 min to 60 min, for example, from 1 min to 50 min, from 1 min to 40 min, from 1 min to 30 min, etc., but is not limited to the listed ranges. Other unlisted values ​​or ranges within this range are also applicable.

[0031] In conjunction with the first aspect, and not wanting to be bound by theory, the specific mechanism of ultraviolet-visible light excitation of semiconductor electrons / holes is as follows: When the energy absorbed by the semiconductor is greater than or equal to the energy of the photon in the band gap (Eg), photogenerated electron-hole pairs are generated. The photogenerated electrons transition to the conduction band, while the photogenerated holes remain in the valence band, and the electrons transition from the top of the valence band to the bottom of the conduction band. Only when the potential of the conduction band edge (photogenerated electrons) is less than the acceptor potential, and the potential of the valence band edge (photogenerated holes) is greater than the acceptor potential, can the excited photogenerated electrons or holes be transferred to the adsorbed molecules in the ground state, thereby causing a redox reaction. In this reaction, acceptors with potentials less than the photogenerated electron potential are reduced, while acceptors with potentials greater than the photogenerated hole potential are oxidized. According to the formula for calculating energy and wavelength, E = hv / λ, the energy E (eV) corresponding to different wavelengths of light sources can be obtained. When the energy of the light source E is greater than the energy of the semiconductor band gap Eg, electrons in the semiconductor valence band can be excited to the conduction band, generating photogenerated electron-hole pairs.

[0032] Furthermore, the energy corresponding to visible light is 1.63 to 3.1 eV, while the energy of ultraviolet light is greater than 3.1 eV.

[0033] In conjunction with the first aspect, in some feasible implementations, the liquid includes at least one of water, an inorganic solution, and an organic solution.

[0034] In conjunction with the first aspect, in some feasible implementations, the liquid includes at least one of a salt solution and an acid solution.

[0035] In conjunction with the first aspect, in some feasible embodiments, the liquid includes at least one of aromatic hydrocarbon organic solutions, aliphatic hydrocarbon organic solutions, alicyclic hydrocarbon organic solutions, halogenated hydrocarbon organic solutions, alcohol organic solutions, ether organic solutions, ester organic solutions, ketone organic solutions, pyridine organic solutions, phenolic organic solutions, nitrile organic solutions, and sulfone organic solutions.

[0036] In conjunction with the first aspect, in some feasible embodiments, the liquid comprises at least one of acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, cyclohexanone, methylcyclohexanone, chlorobenzene, dichlorobenzene, dichloromethane, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, pentanol, diethyl ether, propylene oxide, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, acetone, methyl butyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, pyridine, phenol, styrene, perchloroethylene, trichloroethylene, ethylene glycol ether, and triethanolamine.

[0037] In conjunction with the first aspect, in some feasible embodiments, the liquid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydrobromic acid, hydroiodic acid, boric acid, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, succinic acid, maleic acid, tartaric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, valeric acid, hexanoic acid, decanoic acid, stearic acid, palmitic acid, acrylic acid, ascorbic acid, and malic acid.

[0038] In conjunction with the first aspect, the salt in the salt solution includes at least one of KCl, K2SO4, K2CO3, KNO3, NaCl, Na2SO4, and Na2CO3.

[0039] In conjunction with the first aspect, in some feasible implementations, the container is a sealed container.

[0040] In conjunction with the first aspect, in some feasible embodiments, the container is provided with a stirring device for stirring the liquid, the stirring speed of which is from 100 rpm to 10000 rpm, for example, approximately 200 rpm, approximately 300 rpm, approximately 400 rpm, approximately 500 rpm, approximately 600 rpm, approximately 700 rpm, approximately 800 rpm, approximately 900 rpm, approximately 1000 rpm, approximately 2000 rpm, approximately 3000 rpm, approximately 4000 rpm, approximately 5000 rpm, approximately 6000 rpm, approximately 7000 rpm, approximately 8000 rpm, approximately 9000 rpm, etc., but not limited to the listed values, other unlisted values ​​or ranges within this range are also applicable.

[0041] In conjunction with the first aspect, in some feasible implementations, the container is provided with a stirring device for stirring the liquid, and the stirring speed of the stirring device is 200 rpm to 5000 rpm.

[0042] In conjunction with the first aspect, in some feasible implementations, the pressure inside the container is from 0.3 MPa to 10 MPa, such as 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, etc., but is not limited to the listed values; other unlisted values ​​or ranges within this range are also applicable.

[0043] In conjunction with the first aspect, in some feasible implementations, the pressure inside the container is from 0.5 MPa to 4 MPa.

[0044] In conjunction with the first aspect, in some feasible embodiments, the concentration of nanobubbles in the liquid containing nanobubbles is at least about 1.0 × 10⁻⁶. 10 (number of nanobubbles) / ml, for example, the concentration of nanobubbles in the liquid containing nanobubbles is about 1.0 × 10⁻⁶. 10 (units) / ml to approximately 1.0 × 10 11 (units) / ml, for example 5.0 × 10 10 (units) / ml to approximately 1.0 × 10 11 (pieces) / ml.

[0045] In conjunction with the first aspect, in some feasible implementations, the gas includes at least one of air, nitrogen, oxygen, carbon dioxide, ozone, nitric oxide, nitrogen dioxide, helium, neon, argon, krypton, xenon, and radon.

[0046] In conjunction with the first aspect, in some feasible implementations, the nanobubbles have a particle size of 2 nm to 15 nm; the median particle size of the nanobubbles is 9 nm to 12 nm.

[0047] In conjunction with the first aspect, in some feasible implementations, the Zeta potential of the liquid containing the nanobubbles is -50mV to -70mV, for example -50mV, -51mV, -52mV, -53mV, -54mV, -55mV, -56mV, -57mV, -58mV, -59mV, -60mV, -61mV, -62mV, -63mV, -64mV, -65mV, -66mV, -67mV, -68mV, -69mV, -70mV, etc., but is not limited to the listed values; other unlisted values ​​or ranges within this range also apply.

[0048] In conjunction with the first aspect, in some feasible implementations, the absolute value of the Zeta potential of the liquid containing the nanobubbles decreases by ≤5mV after one month of storage, for example, ≤4mV, ≤3mV, etc.

[0049] In a second aspect, this application provides a liquid containing nanobubbles, which is prepared according to the aforementioned method. The particle size of the nanobubbles is 2nm to 15nm, such as 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, etc., but is not limited to the listed values. Other unlisted values ​​or ranges within this range are also applicable.

[0050] In conjunction with the second aspect, in some feasible implementations, the median particle size of the nanobubbles is 9 nm to 12 nm, such as 9 nm, 10 nm, 11 nm, 12 nm, etc., but is not limited to the listed values. Other unlisted values ​​or ranges within this range are also applicable.

[0051] In conjunction with the second aspect, in some feasible implementations, the Zeta potential of the liquid containing nanobubbles is -50mV to -70mV, such as -50mV, -51mV, -52mV, -53mV, -54mV, -55mV, -56mV, -57mV, -58mV, -59mV, -60mV, -61mV, -62mV, -63mV, -64mV, -65mV, -66mV, -67mV, -68mV, -69mV, -70mV, etc., but is not limited to the listed values; other unlisted values ​​or ranges within this range are also applicable.

[0052] In conjunction with the second aspect, in some feasible implementations, the concentration of nanobubbles in the liquid containing nanobubbles is at least about 1.0 × 10⁻⁶. 10 (number of nanobubbles) / ml, for example, the concentration of nanobubbles in the liquid containing nanobubbles is about 1.0 × 10⁻⁶. 10 (units) / ml to approximately 1.0 × 10 11 (units) / ml, for example 5.0 × 10 10 (units) / ml to approximately 1.0 × 10 11 (pieces) / ml.

[0053] In a third aspect, this application provides an apparatus for preparing nanobubbles, the apparatus comprising a container, a light source, a semiconductor, a liquid, and a gas delivery component, wherein the semiconductor and the liquid are contained in the container, and the liquid immerses at least a portion of the semiconductor.

[0054] The gas delivery component introduces gas into the liquid.

[0055] The light source illuminates the semiconductor and the liquid.

[0056] In conjunction with the third aspect, in some feasible implementations, the gas delivery component includes a vent pipe, a gas cylinder, and a valve.

[0057] For illustrative purposes and not for limitation, in some embodiments, the container includes a shell, which is cylindrical in shape and completely sealed; a hole is provided on the upper left side of the shell for adding liquid and is sealed with a cap; a vent tube is inserted from the upper right side of the shell, the right side of the vent tube is connected to a gas cylinder, and a vent is provided on the upper right side of the shell, all of which are controlled by valves to control the ventilation volume and ventilation rate, and the pressure inside the sealed container is monitored by a pressure sensor.

[0058] Furthermore, the container also includes a stirring device, such as a stirring paddle, which is inserted from the top of the shell to maintain a sealed state inside the shell; a water outlet is provided at the bottom of the shell to discharge the prepared nanobubble liquid; and a light source is placed on the left side inside the shell to emit visible light or ultraviolet light of different wavelengths.

[0059] To avoid being bound by theory, mechanical stirring not only ensures that semiconductor materials or semiconductor particles are evenly distributed in the solution, but also helps the gas generated by photoexcitation to detach from the semiconductor surface and become bulk nanobubbles, thereby obtaining finer, more stable, and more uniform nanobubbles.

[0060] In conjunction with the third aspect, in some feasible implementations, the semiconductor includes at least one of a P-type semiconductor, an N-type semiconductor, a semiconductor having a PN junction, a semiconductor with a doped single-crystal silicon PN junction, a semiconductor with a doped polycrystalline silicon PN junction, a copper indium gallium selenide semiconductor, and a perovskite semiconductor.

[0061] In conjunction with the third aspect, in some feasible implementations, the semiconductor is a nanoparticle semiconductor.

[0062] In conjunction with the third aspect, in some feasible embodiments, the semiconductor includes at least one selected from NiO, MnO, PbO, Pr2O3, TiO2, ZnO, CdS, GaP, Fe2O3, CdSe, Ag2S, FeS, FeS2, PdO, and MnO2.

[0063] In conjunction with the third aspect, in some feasible implementations, the semiconductor includes at least one of TiO2, ZnO, CdS, GaP, Fe2O3, Ag2S, FeS, FeS2, PdO, MnO2, a semiconductor with a doped single-crystal silicon PN junction, a semiconductor with a doped polycrystalline silicon PN junction, a copper indium gallium selenide semiconductor, and a perovskite semiconductor.

[0064] In conjunction with the third aspect, in some feasible implementations, the wavelength of the light source is ≤740nm, for example, ≤730nm, ≤720nm, ≤710nm, ≤700nm, ≤690nm, ≤680nm, ≤670nm, ≤660nm, ≤650nm, ≤640nm, ≤630nm, ≤620nm, ≤610nm, ≤600nm, ≤590nm, ≤580nm, ≤570nm. nm, ≤560nm, ≤550nm, ≤540nm, ≤530nm, ≤520nm, ≤510nm, ≤500nm, ≤490nm, ≤480nm, ≤470nm, ≤460nm, ≤450nm, ≤440nm, ≤430nm, ≤420nm, ≤410nm, ≤400nm, etc., but not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0065] In conjunction with the third aspect, in some feasible implementations, the wavelength of the light source is <400nm, for example, <390nm, <380nm, <370nm, <360nm, <350nm, <340nm, <330nm, <320nm, <310nm, <300nm, <290nm, <280nm, <270nm, <260nm, <250nm, <240nm, <230nm, <220nm, <210nm, <200nm, etc., but is not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0066] In conjunction with the third aspect, in some feasible implementations, the wavelength of the light source is greater than or equal to 400 nm and less than or equal to 740 nm. For example, the wavelength of the light source is greater than or equal to 410 nm and less than or equal to 730 nm, greater than or equal to 420 nm and less than or equal to 720 nm, greater than or equal to 430 nm and less than or equal to 710 nm, greater than or equal to 440 nm and less than or equal to 700 nm, greater than or equal to 450 nm and less than or equal to 690 nm, greater than or equal to 460 nm and less than or equal to 680 nm, greater than or equal to 470 nm and less than or equal to 740 nm. The ranges are 670nm and above, 480nm and below, 490nm and below, 500nm and below, 640nm and above, 510nm and below, 630nm and above, 520nm and below, 620nm and above, 530nm and below, 610nm and above, 540nm and below, and 600nm and above, etc., but are not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0067] In conjunction with the third aspect, in some feasible implementations, the light emitted by the light source is visible light.

[0068] In conjunction with the third aspect, in some feasible implementations, the light emitted by the light source is ultraviolet light.

[0069] In conjunction with the third aspect, in some feasible implementations, the energy of the light emitted by the light source is greater than or equal to 1.63 eV. For example, the energy of the light emitted by the light source is ≥1.64 eV, ≥1.65 eV, ≥1.66 eV, ≥1.67 eV, ≥1.68 eV, ≥1.69 eV, ≥1.70 eV, ≥1.71 eV, ≥1.72 eV, ≥1.73 eV, ≥1.74 eV, ≥1.75 eV, ≥1.76 eV, ≥1.77 eV, ≥1.78 eV, ≥1.79 eV, ≥1.80 eV, ≥1.81 eV, ≥1.82 eV, ≥1.83 eV, ≥1.84 eV, ≥1.85 eV, etc. V, ≥1.86eV, ≥1.87eV, ≥1.88eV, ≥1.89eV, ≥1.90eV, ≥1.91eV, ≥1.92eV, ≥1.93eV, ≥1.94eV, ≥1.95eV, ≥1.96eV, ≥1.97eV, ≥1.98eV, ≥1.99eV, ≥2.0eV, ≥2.1eV, ≥2.2eV, ≥2.3eV, ≥2.4eV, ≥2.5eV, ≥2.6eV, ≥2.7eV, ≥2.8eV, ≥2.9eV, ≥3.0eV, etc., but not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0070] In conjunction with the third aspect, in some feasible implementations, the energy of the light emitted by the light source is from 1.63 eV to 3.1 eV, for example, the energy of the light emitted by the light source is from 1.73 eV to 3.0 eV, 1.83 eV to 2.9 eV, 1.93 eV to 2.9 eV, 2.03 eV to 2.8 eV, 2.13 eV to 2.7 eV, 2.23 eV to 2.6 eV, 2.33 eV to 2.5 eV, etc., but is not limited to the listed ranges; other unlisted values ​​or ranges within this range also apply.

[0071] In conjunction with the third aspect, in some feasible implementations, the energy of the light emitted by the light source is greater than 3.1 eV, for example, the energy of the light emitted by the light source is >3.2 eV, >3.3 eV, >3.4 eV, >3.5 eV, >3.6 eV, >3.7 eV, >3.8 eV, >3.9 eV, >4.0 eV, etc., but is not limited to the listed ranges. Other unlisted values ​​or ranges within this range are also applicable.

[0072] In conjunction with the third aspect, in some feasible implementations, the light source includes at least one of a diode, a tungsten filament lamp, and a fluorescent lamp.

[0073] In conjunction with the third aspect, in some feasible implementations, the irradiation duration of the light source is at least 1 minute, for example at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 11 minutes, at least 12 minutes, at least 13 minutes, at least 14 minutes, at least 15 minutes, at least 16 minutes, at least 17 minutes, at least 18 minutes, at least 19 minutes, at least 20 minutes, at least 21 minutes, at least 22 minutes, at least 23 minutes, at least 24 minutes, at least 25 minutes, at least 26 minutes, at least 27 minutes, at least 28 minutes, at least 29 minutes, at least 30 minutes, at least 31 minutes, at least 32 minutes, at least 33 minutes, or at least 34 minutes. The ranges are: at least 35 minutes, at least 36 minutes, at least 37 minutes, at least 38 minutes, at least 39 minutes, at least 40 minutes, at least 41 minutes, at least 42 minutes, at least 43 minutes, at least 44 minutes, at least 45 minutes, at least 46 minutes, at least 47 minutes, at least 48 minutes, at least 49 minutes, at least 50 minutes, at least 51 minutes, at least 52 minutes, at least 53 minutes, at least 54 minutes, at least 55 minutes, at least 56 minutes, at least 57 minutes, at least 58 minutes, at least 59 minutes, at least 60 minutes, at least 70 minutes, at least 80 minutes, at least 90 minutes, at least 100 minutes, at least 110 minutes, etc., but are not limited to the listed ranges. Other unlisted values ​​or ranges within this range also apply.

[0074] In conjunction with the third aspect, in some feasible implementations, the irradiation duration of the light source is from 1 min to 120 min, such as 2 min to 110 min, 5 min to 100 min, 10 min to 90 min, 20 min to 80 min, 30 min to 70 min, 40 min to 60 min, etc., but is not limited to the listed ranges. Other unlisted values ​​or ranges within this range are also applicable.

[0075] In conjunction with the third aspect, in some feasible implementations, the irradiation time of the light source is from 1 minute to 60 minutes, for example, from 1 minute to 50 minutes, from 1 minute to 40 minutes, from 1 minute to 30 minutes, etc., but is not limited to the listed ranges. Other unlisted values ​​or ranges within this range are also applicable.

[0076] In conjunction with the third aspect, in some feasible implementations, the liquid includes at least one of water, an inorganic solution, and an organic solution.

[0077] In conjunction with the third aspect, in some feasible implementations, the liquid includes at least one of a salt solution and an acid solution.

[0078] In conjunction with the third aspect, in some feasible embodiments, the liquid includes at least one of aromatic hydrocarbon organic solutions, aliphatic hydrocarbon organic solutions, alicyclic hydrocarbon organic solutions, halogenated hydrocarbon organic solutions, alcohol organic solutions, ether organic solutions, ester organic solutions, ketone organic solutions, pyridine organic solutions, phenolic organic solutions, nitrile organic solutions, and sulfone organic solutions.

[0079] In conjunction with the third aspect, in some feasible embodiments, the liquid comprises at least one of acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, cyclohexanone, methylcyclohexanone, chlorobenzene, dichlorobenzene, dichloromethane, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, pentanol, diethyl ether, propylene oxide, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, acetone, methyl butyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, pyridine, phenol, styrene, perchloroethylene, trichloroethylene, ethylene glycol ether, and triethanolamine.

[0080] In conjunction with the third aspect, in some feasible implementations, the liquid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydrobromic acid, hydroiodic acid, boric acid, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, succinic acid, maleic acid, tartaric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, valeric acid, hexanoic acid, decanoic acid, stearic acid, palmitic acid, acrylic acid, ascorbic acid, and malic acid.

[0081] In conjunction with the third aspect, the salt in the salt solution includes at least one of KCl, K2SO4, K2CO3, KNO3, NaCl, Na2SO4, and Na2CO3.

[0082] In conjunction with the third aspect, in some feasible implementations, the container is a sealed container.

[0083] In conjunction with the third aspect, in some feasible embodiments, the container is provided with a stirring device for stirring the liquid. The stirring speed of the stirring device is from 100 rpm to 10,000 rpm, for example, approximately 200 rpm, approximately 300 rpm, approximately 400 rpm, approximately 500 rpm, approximately 600 rpm, approximately 700 rpm, approximately 800 rpm, approximately 900 rpm, approximately 1,000 rpm, approximately 2,000 rpm, approximately 3,000 rpm, approximately 4,000 rpm, approximately 5,000 rpm, approximately 6,000 rpm, approximately 7,000 rpm, approximately 8,000 rpm, approximately 9,000 rpm, etc., but is not limited to the listed values. Other unlisted values ​​or ranges within this range are also applicable.

[0084] In conjunction with the third aspect, in some feasible implementations, the container is provided with a stirring device for stirring the liquid, and the stirring speed of the stirring device is from 200 rpm to 5000 rpm.

[0085] In conjunction with the third aspect, in some feasible implementations, the pressure inside the container is from 0.3 MPa to 10 MPa, such as 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, etc., but is not limited to the listed values; other unlisted values ​​or ranges within this range are also applicable.

[0086] In conjunction with the third aspect, in some feasible implementations, the pressure inside the container is 0.5 MPa to 4 MPa.

[0087] In conjunction with the third aspect, in some feasible implementations, the gas includes at least one of air, nitrogen, oxygen, carbon dioxide, ozone, nitric oxide, nitrogen dioxide, helium, neon, argon, krypton, xenon, and radon.

[0088] In conjunction with the third aspect, in some feasible implementations, the nanobubbles have a particle size of 2 nm to 15 nm; the median particle size of the nanobubbles is 9 nm to 12 nm.

[0089] In conjunction with the third aspect, in some feasible implementations, the Zeta potential of the liquid containing the nanobubbles is -50mV to -70mV, such as -50mV, -51mV, -52mV, -53mV, -54mV, -55mV, -56mV, -57mV, -58mV, -59mV, -60mV, -61mV, -62mV, -63mV, -64mV, -65mV, -66mV, -67mV, -68mV, -69mV, -70mV, etc., but not limited to the listed values; other unlisted values ​​or ranges within this range also apply.

[0090] In conjunction with the third aspect, in some feasible implementations, the absolute value of the Zeta potential of the liquid containing the nanobubbles decreases by ≤5mV after one month of storage, for example, ≤4mV or ≤3mV.

[0091] In conjunction with the third aspect, in some feasible implementations, the concentration of nanobubbles in the liquid containing nanobubbles is at least about 1.0 × 10⁻⁶. 10 (number of nanobubbles) / ml, for example, the concentration of nanobubbles in the liquid containing nanobubbles is about 1.0 × 10⁻⁶. 10 (units) / ml to approximately 1.0 × 10 11 (units) / ml, for example 5.0 × 10 10 (units) / ml to approximately 1.0 × 10 11 (pieces) / ml.

[0092] For illustrative purposes and not for limitation, in some feasible embodiments, the container is either opaque or light-permeable. The light transmittance of the container is 0, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%. When the light transmittance of the container is 0, the light source is located inside the container.

[0093] It should be noted that when the light transmittance of the container is not 0, for example, when the light transmittance is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, etc., the light source can be placed outside the container to illuminate the inside of the container.

[0094] As an alternative implementation, this application provides an apparatus for preparing nanobubbles, the apparatus comprising a container, a light source, a semiconductor, a liquid, and a gas delivery component, wherein the semiconductor and the liquid are contained in the container, and the liquid immerses at least a portion of the semiconductor.

[0095] The gas delivery component introduces gas into the liquid.

[0096] The light source illuminates the semiconductor and the liquid.

[0097] The container includes a shell, an openable and closable orifice, a stirring device, a vent pipe, a pressure sensor, a vent, and a water outlet.

[0098] The container is closed. The container may include an outer shell welded to the housing to maintain a sealed state inside the housing.

[0099] The light source includes a light-emitting device and a controller. The controller controls the wavelength and duration of the light emitted by the light-emitting device. The controller is equipped with buttons or knobs to control the wavelength and duration of the light emitted by the light-emitting device. The light-emitting device and the controller can be connected via connecting wires.

[0100] The term “multiple” as used in this article includes two, three, four or more, etc.

[0101] The external environment mentioned in this article generally refers to room temperature conditions, such as 15°C to 35°C, but other conditions are not excluded. In actual operation, the temperature of the experimental conditions will be changed according to specific needs.

[0102] The normal temperature referred to in this article is usually 15℃ to 35℃, but other conditions, such as -10℃ to 50℃, are not excluded.

[0103] Unless otherwise specified herein, the purity grade of the substances purchased or used herein is chemically pure, analytically pure, or superior pure, preferably analytically pure, and more preferably superior pure.

[0104] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0105] (1) This invention generates photogenerated electron-hole pairs by exciting semiconductor nanoparticles with visible light and ultraviolet light, so that the solute in the solution is oxidized / reduced to generate gas nuclei. Under the combined action of stirring, nanobubbles are generated. At the same time, nanobubble solutions with different particle sizes and concentrations can be obtained by controlling the irradiation time and light wavelength.

[0106] (2) The present invention can prepare small and uniform nanobubbles that can exist stably in the solution. The particle size of the nanobubbles is mainly concentrated in the range of 2nm to 15nm, which greatly improves the specific surface area of ​​the nanobubbles and enhances the treatment effect of the nanobubble solution. At the same time, the obtained nanobubble solution can be kept for more than a month and has a long storage time.

[0107] (3) The device of the present invention has a simple structure, is easy to operate, has low time cost, low energy consumption during operation, outstanding effect, wide range of raw material sources, high production efficiency, and can control gas source, and can be widely used in industry. Attached Figure Description

[0108] Figure 1 A schematic diagram of the apparatus for preparing nanobubbles according to the present invention is shown;

[0109] Figure 2 A schematic diagram of the particle size distribution of the nanobubbles prepared in Example 1 is shown;

[0110] Figure 3 The peak Zeta potentials of the nanobubbles in Example 1 are shown 1 hour after preparation and 1 month after preparation and storage.

[0111] Figure 4 The nanobubble particle size distribution diagrams of Example 1, Comparative Example 1, and Comparative Example 2 are shown.

[0112] Figure 5 The peak Zeta potential diagrams of nanobubbles in Examples 1 and 2 are shown;

[0113] Figure 6 The nanobubble particle size distribution diagrams of Example 2 and Comparative Example 3 are shown;

[0114] Figure 7 The nanobubble particle size distribution diagrams of Example 3 and Comparative Example 4 are shown;

[0115] Figure 8 The particle size distribution of nanobubbles in Example 4 and Comparative Example 5 is shown. Detailed Implementation

[0116] To better explain the present invention, the embodiments of this application will be described in detail below with reference to specific examples. However, those skilled in the art will understand that the following examples are only for illustrating the present application and should not be regarded as limiting the scope of the present application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0117] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Further understanding is that terms, such as those defined in common dictionaries, are interpreted in accordance with their meaning in the context of the relevant field and are not idealized or overly formal, unless expressly defined herein.

[0118] Unless otherwise stated in this document or there is a clear contradiction in the context, all methods described herein may be performed in any suitable order.

[0119] Unless otherwise stated, the use of any and all embodiments or exemplary language (such as "for example") provided herein is intended only to better illustrate the invention and not to limit the scope of the invention. Unless explicitly stated otherwise, the language in this specification should not be construed as indicating that any element is essential to carrying out the invention.

[0120] As used in this application, the term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely and examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format in this application. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0121] The exemplary invention described herein may suitably omit any one or more limiting elements, which are not specifically disclosed herein. Therefore, terms such as “comprising,” “including,” “containing,” etc., should be interpreted broadly and non-limitingly. Furthermore, the terminology used herein is for descriptive purposes without limitation, and it is unintentional to use terms that do not include any equivalent characteristics, but only to describe a portion of their characteristics; however, various modifications are possible within the scope of the invention according to the claims. Therefore, while the invention has been specifically disclosed through preferred embodiments and optional features, variations of the invention embodied by the modifications disclosed herein may be noted by those skilled in the art, and such modifications and variations are considered to be within the scope of the invention.

[0122] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0123] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0124] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 10” is disclosed, the described range should be interpreted as including ranges “1 to 10”, “1 to 9”, “1 to 8”, “1 to 7”, “1 to 6”, “1 to 5”, “1 to 4”, “1 to 3”, “1 to 2”, “1 to 3 and 5 to 10”, “1 to 4 and 8”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0125] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0126] Furthermore, the terms "first," "second," and "third" as used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of embodiments of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0127] Example 1

[0128] An apparatus for preparing nanobubbles, Figure 1 This embodiment provides an apparatus for preparing nanobubbles. The apparatus includes a housing 1, which is a hollow cylinder and completely sealed. A cylindrical hole 2 is provided on the top of the housing 1 for adding liquid, and the hole is sealed with a lid. A vent pipe 4 is inserted from the upper right side of the housing 1, and the right side of the vent pipe 4 is connected to a gas cylinder. A vent 6 is provided on the upper right side of the housing 1. The ventilation volume and rate are controlled by valves, and the pressure inside the sealed container is monitored by a pressure sensor 5. A stirring paddle 7 is inserted from the top of the housing 1, and a shell 3 welded to the housing is provided on the outside of the stirring paddle 7 to maintain the sealed state inside the housing. A water outlet 8 is provided at the bottom of the housing for obtaining the prepared nanobubble solution; a light source is placed on the left side of the housing 1 to emit visible light or ultraviolet light of different wavelengths. The vent pipe 4, the vent 6, and the water outlet 8 are all controlled by valves.

[0129] This embodiment also provides a method for preparing oxygen nanobubbles, using PbO semiconductor particles (2.8 eV, photogenerated electron-hole potential of -0.5 to 2.3 eV), adjusting the concentration of NaCl in the aqueous solution to 0.01 mol / L, and irradiating with blue light (2.76 to 2.85 eV). The specific steps are as follows:

[0130] (1) Degassing: Open the vent 6 and close the outlet 8. Add 5g of PbO particles and 5L of 0.01mol / L sodium chloride aqueous solution to the shell 1 of the container at the same time. Turn on the stirring paddle 7 of the mechanical stirrer to make the PbO particles evenly distributed in the solution. Introduce oxygen into the container. When the oxygen concentration at the outlet can reach 80 vol% by using an oxygen detector, close the vent 6.

[0131] (2) Preparation of nanobubbles: Continue to introduce oxygen into the sealed container until the pressure inside the container reaches 0.7 MPa, so that the oxygen in the solution is supersaturated; turn on the light source (including light-emitting device 9 and controller 10), and under the irradiation of visible blue light, realize the electron transfer between PbO particles and H2O in the solution, and generate oxygen nuclei on the surface of PbO particles; stir at 400 rpm and irradiate for 20 min. During this period, the oxygen in the solution enters a higher supersaturated state and continuously generates gas nuclei. In addition, the shear force of the stirring blades also helps the bubbles to detach from the surface of PbO particles and enter the bulk solution, thereby generating smaller and more uniform nanobubbles; after the end, open the outlet 8 to obtain the nanobubble solution.

[0132] Figure 2 This is a schematic diagram of the particle size distribution of the prepared nanobubbles. Figure 3 The images show the peak Zeta potentials of the nanobubbles after 1 hour of preparation and after one month of storage, demonstrating that the prepared nanobubbles are highly stable and retain their original Zeta potentials even after a month. In this example, the final median particle size was approximately 11.74 nm, and the concentration was approximately 6.80 × 10⁻⁶. 10 (number) / ml, uniform and stable oxygen nanobubbles, and the solution can be stored for more than a month.

[0133] Comparative Example 1

[0134] The apparatus, operating procedures, and conditions for Comparative Example 1 were basically the same as those for Example 1, except that stirring was not used in Comparative Example 1. In Comparative Example 1, 5g of PbO nanoparticles and 5L of 0.01mol / L sodium chloride were added, and blue light irradiation was applied for 20 minutes. The resulting nanobubbles had a median particle size of approximately 118.12nm and a concentration of approximately 2.72 × 10⁻⁶. 8 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 1 was -39mV after 1 hour of preparation, -34mV after two weeks of storage, and -21mV after one month of storage.

[0135] Under the same test conditions as in Example 1, the particle size and concentration of nanobubbles in Example 1 and Comparative Example 1 were compared with those obtained by stirring and those obtained by not stirring. It can be clearly seen that the nanobubbles obtained by stirring have smaller particle size, higher concentration, and longer storage time, indicating that the shear force of the blades during the stirring process has a significant effect on the bubbles.

[0136] Comparative Example 2

[0137] Comparative Example 2 used essentially the same apparatus, operating procedures, and conditions as Example 1, except that it did not use a light source, but only natural light. 5g of PbO and 5L of 0.01mol / L sodium chloride were added, the stirring speed was 400rpm, and the natural light irradiation time was 20min. The final nanobubbles had a median particle size of approximately 106.73nm and a concentration of approximately 5.67*10⁻⁶. 8 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 2 was -42mV after 1 hour of preparation, -38mV after two weeks of storage, and -23mV after one month of storage.

[0138] Under the same test conditions as in Example 1, the particle size and concentration of nanobubbles in Example 1 and Comparative Example 2 were compared, respectively irradiated with blue light and natural light. Since the energy of visible light with a wavelength longer than blue light in natural light cannot reach the excitation energy of electrons in PbO, the amount of energy that can be effectively utilized is small. At the same time, the results clearly show that the nanobubbles obtained by irradiation with blue light in Example 1 have small particle size, high concentration and long storage time.

[0139] Figure 4 These are the nanobubble particle size distribution diagrams of Example 1, Comparative Example 1, and Comparative Example 2. By comparison, it can be found that mechanical stirring and light source are indispensable in the process of preparing nanobubbles by visible light excitation of semiconductor particles. Both of these have a great influence on the preparation of nanobubbles with small particle size, high concentration, and stability.

[0140] Example 2

[0141] This embodiment provides a method for preparing oxygen nanobubbles. The semiconductor particles used are PbO (2.8 eV, photogenerated electron-hole potential of -0.5 to 2.3 eV), the solution is 0.01 M sodium chloride, and ultraviolet light (3.5 eV) is used for irradiation. The specific steps are as follows:

[0142] (1) Degassing: Open the vent 6 and close the outlet 8. Add 5g of PbO particles and 5L of 0.01mol / L sodium chloride to the container at the same time. Turn on the mechanical stirrer 7 to make the PbO particles evenly distributed in the solution. Introduce oxygen into the container. When the oxygen concentration at the outlet can reach 80 vol% using an oxygen detector, close the vent 6.

[0143] (2) Preparation of nanobubbles: Oxygen was continuously introduced into a sealed container until the pressure inside the container reached 0.7 MPa, so that the oxygen in the solution was supersaturated; the light source was turned on, and under the irradiation of ultraviolet light, electron transfer between PbO particles and H2O in the solution was realized, and oxygen nuclei were generated on the surface of PbO particles; the stirring speed was 400 rpm and the irradiation time was 30 min. During this period, the oxygen in the solution entered a higher supersaturated state and continuously generated gas nuclei. In addition, the shear force of the stirring blades also helped the bubbles to detach from the surface of PbO particles and enter the bulk solution, thereby generating smaller and more uniform nanobubbles; after the end, the outlet 8 was opened to obtain an oxygen nanobubble solution.

[0144] Example 2 ultimately yielded a median particle size of approximately 7.83 nm and a concentration of approximately 8.42 × 10⁻⁶. 10 / ml, uniform and stable oxygen nanobubbles, and the solution can be preserved for more than one and a half months. Figure 5 As shown, comparing Example 1 and Example 2, it was found that when the wavelength of the irradiation light was shorter and the irradiation time was longer, the resulting nanobubbles had smaller particle size, more negative Zeta potential, greater number / concentration, and were more stable.

[0145] Comparative Example 3

[0146] Comparative Example 3 used the existing pressurized-mechanical stirring technique studied in patent CN106732116A to prepare nanobubbles. The aeration, pressurization, and stirring process were the same as in Example 2: 5 L of 0.01 mol / L sodium chloride solution was used, oxygen was introduced to a pressure of 0.7 MPa, and the reaction time was 30 min. The difference was that no semiconductor particles or light source were added, and the mechanical stirring speed was 2000 rpm. The final nanobubbles had a median particle size of approximately 160 nm and a concentration of approximately 6.98 × 10⁻⁶. 6 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 3 was -28mV after 1 hour of preparation, -23mV after two weeks of storage, and -10mV after one month of storage.

[0147] Figure 6 These are the nanobubble particle size distribution diagrams of Example 2 and Comparative Example 3. By comparison, it can be seen that under the same test conditions as Example 2, although the stirring speed of Comparative Example 3 is much higher than that of Example 2, the nanobubble particle size (7.83 nm) produced in Example 2 is smaller and has a larger specific surface area than the nanobubble particle size (160 nm) of Comparative Example 3 in the same time period. At the same time, it has a longer storage time and stronger stability.

[0148] Example 3

[0149] This embodiment provides a method for preparing nitrogen nanobubbles. The semiconductor nanoparticles used are CdSe (1.7 eV, photogenerated electron-hole potential of -0.7 to 1.0 V), the solution is 0.01 M ammonium chloride, and orange light (1.99 to 2.08 eV) is used for irradiation. The specific steps are as follows:

[0150] The specific steps are as follows:

[0151] (1) Degassing: Open the vent 6 and close the outlet 8. Add 5g of CdSe particles and 5L of 0.01mol / L ammonium chloride to the container at the same time. Turn on the stirring paddle 7 of the mechanical stirrer to make the CdSe particles evenly distributed in the solution. Introduce nitrogen into the container. When the nitrogen concentration at the outlet can reach 80vol% by using a nitrogen detector, close the vent 6.

[0152] (2) Preparation of nanobubbles: Nitrogen gas was continuously introduced into a sealed container until the pressure inside the container reached 1.5 MPa, so that the nitrogen gas in the solution was supersaturated; the light source was turned on, and under the irradiation of visible orange light, electron transfer between CdSe particles and H2O in the solution was realized, and nitrogen nuclei were generated on the surface of CdSe particles; the stirring speed was 400 rpm and the irradiation time was 20 min. During this period, the nitrogen gas in the solution entered a higher supersaturated state and continuously generated gas nuclei. In addition, the shear force of the stirring blades also helped the bubbles to detach from the surface of CdSe particles and enter the bulk solution, thereby generating smaller and more uniform nanobubbles; after the end, the outlet 8 was opened to obtain a nitrogen nanobubble solution.

[0153] Example 3 ultimately yielded particles with a median particle size of approximately 11.34 nm and a concentration of approximately 6.95 × 10⁻⁶. 10 The solution contains uniform and stable nitrogen nanobubbles per ml, and the solution can be stored for more than one month. In Example 3, the zeta potential was -62 mV after 1 hour of preparation and -58 mV after one month of storage.

[0154] Comparative Example 4

[0155] Comparative Example 4 used the existing ultrasonic cavitation method studied in patent CN114950223A to prepare nanobubbles. The gas-pressurization process was the same as in Example 2, using 5 L of 0.01 mol / L ammonium chloride solution, introducing nitrogen gas to a pressure of 1.5 MPa, and a reaction time of 20 min. The difference was that semiconductor particles, a light source, and mechanical stirring were not used, and the ultrasonic power was 100 W. The final nanobubbles obtained had a particle size of approximately 146 nm and a concentration of approximately 8.64 × 10⁻⁶. 6 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 4 was -32mV after 1 hour of preparation, -28mV after two weeks of storage, and -13mV after one month of storage.

[0156] Figure 7 These are the nanobubble particle size distribution diagrams of Example 3 and Comparative Example 4. By comparison, it can be seen that under the same test conditions as Example 3 and within the same time period, the nanobubble particle size (11.34 nm) produced in Example 3 is smaller and has a larger specific surface area than the nanobubble particle size (146 nm) of Comparative Example 4. At the same time, it has a longer storage time and stronger stability.

[0157] Example 4

[0158] This embodiment provides a method for preparing oxygen nanobubbles. The semiconductor nanoparticles used are doped polycrystalline silicon PN junctions, the solution is 0.01M sodium chloride, and blue light (2.76–2.85 eV) is used for irradiation. The specific steps are as follows:

[0159] The specific steps are as follows:

[0160] (1) Degassing: Open the vent 6 and close the outlet 8. Add 5g of doped polycrystalline silicon PN junction particles and 5L of 0.01mol / L sodium chloride to the container at the same time. Turn on the stirring paddle 7 of the mechanical stirrer to make the doped polycrystalline silicon PN junction particles evenly distributed in the solution. Introduce oxygen into the container. When the oxygen concentration at the outlet can reach 80vol% by using an oxygen detector, close the vent 6.

[0161] (2) Preparation of nanobubbles: Continue to introduce oxygen into a sealed container until the pressure inside the container reaches 1 MPa, so that the oxygen in the solution is supersaturated; turn on the light source, and under the irradiation of visible blue light, realize the electron transfer between the doped polycrystalline silicon PN junction particles and H2O in the solution, and generate oxygen nuclei on the surface of the nanoparticles; stir at 500 rpm and irradiate for 10 min. During this period, the oxygen in the solution enters a higher supersaturated state and continuously generates gas nuclei. In addition, the shear force of the stirring blades also helps the bubbles to detach from the surface of the doped polycrystalline silicon PN junction particles and enter the bulk solution, thereby generating smaller and more uniform nanobubbles; after the end, open the outlet 8 to obtain the oxygen nanobubble solution.

[0162] Example 4 yielded a median particle size of approximately 8.48 nm and a concentration of approximately 8.07 × 10⁻⁶. 10 The solution contains uniform and stable oxygen nanobubbles per ml, and the solution can be stored for more than a month. In Example 4, the zeta potential was -65 mV after 1 hour of preparation and -62 mV after 1 month of storage.

[0163] Comparative Example 5

[0164] Comparative Example 5 used existing electrocatalytic technology based on patent CN117084293A to prepare nanobubbles. In a sealed container, 5 L of 0.01 mol / L sodium chloride solution was added. Oxygen molecules were generated at the anode. When the oxygen molecule concentration reached the nucleation critical concentration, nanobubbles spontaneously formed on the electrode surface. The reaction time was 20 min. The final nanobubbles had a particle size of approximately 153 nm and a concentration of approximately 8.33 × 10⁻⁶. 6 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 4 was -29mV after 1 hour of preparation, -24mV after two weeks of storage, and -15mV after one month of storage.

[0165] Figure 8 These are the nanobubble particle size distribution diagrams of Example 2 and Comparative Example 3. By comparison, it can be seen that under the same test conditions as Example 4, although the reaction time of Comparative Example 5 is longer than that of Example 4, the nanobubble particle size (8.48 nm) produced in Example 4 is smaller and has a larger specific surface area than the nanobubble particle size (153 nm) of Comparative Example 5. At the same time, it has a longer storage time and stronger stability.

[0166] Example 5

[0167] An apparatus for preparing nanobubbles, the apparatus comprising a container, a light source, a semiconductor, a liquid, and a gas delivery component, wherein the semiconductor and the liquid are contained in the container, and the liquid immerses at least a portion of the semiconductor;

[0168] The gas delivery component introduces gas into the liquid;

[0169] The light source illuminates the semiconductor and the liquid.

[0170] The device includes a container with a shell 1, which is a hollow cylinder and completely sealed. A cylindrical hole 2 is provided at the top of the shell 1 for adding liquid, and the hole is sealed with a lid. A vent pipe 4 is inserted from the upper right side of the shell 1, and the right side of the vent pipe 4 is connected to a gas cylinder. A vent 6 is located at the upper right of the shell 1. The ventilation volume and rate are controlled by valves, and the pressure inside the sealed container is monitored by a pressure sensor 5. A stirring paddle 7 is inserted from the top of the shell 1, and a shell 3 welded to the shell is provided for the stirring paddle 7 to maintain the sealed state inside the shell. A water outlet 8 is located at the bottom of the shell for obtaining the prepared nanobubble solution. A light source is placed on the left side of the shell 1 to emit visible or ultraviolet light of different wavelengths. The vent pipe 4, vent 6, and water outlet 8 are all controlled by valves. The light source includes a light-emitting device 9 and a controller 10, which controls the wavelength and emission time of the light emitted by the light-emitting device 9.

[0171] This embodiment also provides a method for preparing oxygen nanobubbles, including:

[0172] A semiconductor and a liquid are added to a container, wherein the liquid immerses at least a portion of the semiconductor;

[0173] Gas is introduced into the liquid;

[0174] The semiconductor and the liquid are illuminated with a light source.

[0175] The semiconductor is a semiconductor particle.

[0176] The semiconductor particles used were MnO (3.6 eV). NaCl was added to the aqueous solution to adjust its concentration to 0.01 mol / L, and ultraviolet light (4.0 eV) was used for irradiation. The specific steps are as follows:

[0177] (1) Degassing: Open the vent 6 and close the water outlet 8. Add 5g of MnO particles and 5L of aqueous solution containing 0.01mol / L sodium chloride to the shell 1 of the container at the same time. Turn on the stirring paddle 7 of the mechanical stirrer to make the MnO particles evenly distributed in the solution. Introduce oxygen into the container. When the oxygen concentration at the outlet can reach 80 vol% by using an oxygen detector, close the vent 6.

[0178] (2) Preparation of nanobubbles: Continue to introduce oxygen into the sealed container until the pressure inside the container reaches 0.3 MPa, so that the oxygen in the solution is supersaturated; turn on the light source (including light-emitting device 9 and controller 10), and under the irradiation of visible light, realize the electron transfer between MnO particles and H2O in the solution, and generate oxygen nuclei on the surface of MnO particles; stir at 300 rpm and irradiate for 15 min. During this period, the oxygen in the solution enters a higher supersaturated state and continuously generates gas nuclei. In addition, the shear force of the stirring blades also helps the bubbles to detach from the surface of MnO particles and enter the bulk solution, thereby generating smaller and more uniform nanobubbles; after the end, open the outlet 8 to obtain the nanobubble solution.

[0179] In this embodiment, the median particle size was approximately 10.35 nm, and the concentration was approximately 7.20 × 10⁻⁶. 10 The solution contains uniform and stable oxygen nanobubbles per ml, and the solution can be stored for more than a month. In Example 5, the zeta potential was -61 mV after 1 hour of preparation and -58 mV after 1 month of storage.

[0180] Comparative Example 6

[0181] Comparative Example 6 is the same as Example 1, except that in step (2) the nanobubbles are prepared: oxygen is continuously introduced into the sealed container until the pressure inside the container reaches 0.1 MPa, and the rest is the same.

[0182] The final nanobubbles had a median particle size of approximately 125.69 nm and a concentration of approximately 2.01 × 10⁻⁶. 8 / ml, storage time is approximately two weeks. The Zeta potential of Comparative Example 1 was -37mV after 1 hour of preparation, -32mV after two weeks of storage, and -20mV after one month of storage.

[0183] The above description is merely a specific embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made using the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

[0184] For conditions not specifically specified in the examples, standard conditions or manufacturer-recommended conditions were followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available standard products.

Claims

1. A method for producing nanobubbles, characterized by, include: A semiconductor and a liquid are added to a container, wherein the liquid immerses at least a portion of the semiconductor; the container is a sealed container. The container is equipped with a stirring device for stirring the liquid, and the stirring speed of the stirring device is from 100 rpm to 10,000 rpm; the pressure inside the container is from 0.3 MPa to 10 MPa. Gas is introduced into the liquid until the gas is saturated or supersaturated in the solution; The semiconductor and the liquid are irradiated with a light source; the wavelength of the light source is ≤740nm. The zeta potential of the liquid containing the nanobubbles is 50 mV to 70 mV; the concentration of nanobubbles in the liquid containing nanobubbles is at least 1.0 × 10⁻⁶ mV. 10 per ml.

2. The method according to claim 1, characterized in that, The semiconductor satisfies any one of the following conditions (1) to (4): (1) The semiconductor includes at least one of P-type semiconductor, N-type semiconductor, semiconductor with PN junction, semiconductor with doped single-crystal silicon PN junction, semiconductor with doped polycrystalline silicon PN junction, copper indium gallium selenide semiconductor, and perovskite semiconductor; (2) The semiconductor is a nanoparticle semiconductor; (3) The semiconductor includes at least one of NiO, MnO, PbO, Pr2O3, TiO2, ZnO, CdS, GaP, Fe2O3, CdSe, Ag2S, FeS, FeS2, PdO, and MnO2; (4) The semiconductor includes at least one of TiO2, ZnO, CdS, GaP, Fe2O3, Ag2S, FeS, FeS2, PdO, MnO2, semiconductors with doped single-crystal silicon PN junctions, semiconductors with doped polycrystalline silicon PN junctions, copper indium gallium selenide semiconductors, and perovskite semiconductors.

3. The method according to claim 1, characterized in that, The light source satisfies any one of the following conditions from a to k: a. The wavelength of the light source is <400nm; b. The wavelength of the light source is greater than or equal to 400 nm and less than or equal to 740 nm; c. The light emitted by the light source is visible light; d. The light emitted by the light source is ultraviolet light; e. The energy of the light emitted by the light source is greater than or equal to 1.63 eV; f. The energy of the light emitted by the light source is between 1.63 eV and 3.1 eV; g. The energy of the light emitted by the light source is greater than 3.1 eV; h. The light source includes at least one of diodes, tungsten filament lamps, and fluorescent lamps; i. The illumination time of the light source is at least 1 minute; j. The illumination time of the light source is from 1 min to 120 min; k. The illumination time of the light source is from 1 min to 60 min.

4. The method according to claim 1, characterized in that, The liquid satisfies any one of the following conditions A through E: A. The liquid includes at least one of water, inorganic solution, and organic solution; B. The liquid includes at least one of a salt solution and an acid solution; C. The liquid comprises at least one of the following: aromatic hydrocarbon organic solutions, aliphatic hydrocarbon organic solutions, alicyclic hydrocarbon organic solutions, halogenated hydrocarbon organic solutions, alcohol organic solutions, ether organic solutions, ester organic solutions, ketone organic solutions, pyridine organic solutions, phenolic organic solutions, nitrile organic solutions, and sulfone organic solutions; D. The liquid includes acetonitrile, N,N Dimethylformamide, dimethyl sulfoxide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, cyclohexanone, toluenecyclohexanone, chlorobenzene, dichlorobenzene, dichloromethane, methanol, ethanol, 1 Propanol, 2 Propanol, 1 Butanol, 2 At least one of the following: butanol, pentanol, diethyl ether, propylene oxide, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, acetone, methyl butyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, pyridine, phenol, styrene, perchloroethylene, trichloroethylene, ethylene glycol ether, and triethanolamine; E. The liquid comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydrobromic acid, hydroiodic acid, boric acid, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, succinic acid, maleic acid, tartaric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, valeric acid, hexanoic acid, decanoic acid, stearic acid, palmitic acid, acrylic acid, ascorbic acid, and malic acid.

5. The method according to any one of claims 1 to 4, characterized in that, The method satisfies any one of the following conditions i to v: i. The stirring speed of the stirring device is from 200 rpm to 5000 rpm; ii. The pressure inside the container is between 0.5 MPa and 4 MPa; iii. The gas includes at least one of air, nitrogen, oxygen, carbon dioxide, ozone, nitric oxide, nitrogen dioxide, helium, neon, argon, krypton, xenon, and radon; iv. The nanobubbles have a particle size of 2 nm to 15 nm; the median particle size of the nanobubbles is 9 nm to 12 nm; v. The absolute value of the Zeta potential of the liquid containing the nanobubbles decreases by ≤5 mV after one month of storage.

6. A liquid containing nanobubbles, characterized in that, The liquid containing nanobubbles is prepared by the method according to any one of claims 1 to 5, wherein the particle size of the nanobubbles is 2 nm to 15 nm; the median particle size of the nanobubbles is 9 nm to 12 nm; and the zeta potential of the liquid containing nanobubbles is [missing value]. 50 mV to 70 mV.

7. The liquid according to claim 6, characterized in that, The concentration of the nanobubbles contained in the liquid containing nanobubbles is at least 1.0 x 10 10 per ml.

8. An apparatus for preparing nanobubbles, characterized in that, The device includes a container, a light source, a semiconductor, a liquid, and a gas delivery component. The semiconductor and the liquid are contained in the container, and the liquid immerses at least a portion of the semiconductor. The container is a sealed container. A stirring device is provided inside the container for stirring the liquid, and the stirring speed of the stirring device is from 100 rpm to 10,000 rpm. The pressure inside the container is from 0.3 MPa to 10 MPa. The gas supply component introduces gas into the liquid until the gas is saturated or supersaturated in the solution; The light source irradiates the semiconductor and the liquid; the wavelength of the light source is ≤740nm; The zeta potential of the liquid containing the nanobubbles is 50 mV to 70 mV; the concentration of nanobubbles in the liquid containing nanobubbles is at least 1.0 × 10⁻⁶ mV. 10 per ml.

9. The apparatus according to claim 8, characterized in that, The device satisfies any one of the following conditions (1) to (4): (1) The semiconductor includes at least one of P-type semiconductor, N-type semiconductor, semiconductor with PN junction, semiconductor with doped single-crystal silicon PN junction, semiconductor with doped polycrystalline silicon PN junction, copper indium gallium selenide semiconductor, and perovskite semiconductor; (2) The semiconductor is a nanoparticle semiconductor; (3) The semiconductor includes at least one of NiO, MnO, PbO, Pr2O3, TiO2, ZnO, CdS, GaP, Fe2O3, CdSe, Ag2S, FeS, FeS2, PdO, and MnO2; (4) The semiconductor includes at least one of TiO2, ZnO, CdS, GaP, Fe2O3, Ag2S, FeS, FeS2, PdO, MnO2, semiconductors with doped single-crystal silicon PN junctions, semiconductors with doped polycrystalline silicon PN junctions, copper indium gallium selenide semiconductors, and perovskite semiconductors.

10. The apparatus according to claim 8, characterized in that, The device satisfies any one of the following conditions a to k: a. The wavelength of the light source is <400nm; b. The wavelength of the light source is greater than or equal to 400 nm and less than or equal to 740 nm; c. The light emitted by the light source is visible light; d. The light emitted by the light source is ultraviolet light; e. The energy of the light emitted by the light source is greater than or equal to 1.63 eV; f. The energy of the light emitted by the light source is between 1.63 eV and 3.1 eV; g. The energy of the light emitted by the light source is greater than 3.1 eV; h. The light source includes at least one of diodes, tungsten filament lamps, and fluorescent lamps; i. The illumination time of the light source is at least 1 minute; j. The illumination time of the light source is from 1 min to 120 min; k. The illumination time of the light source is from 1 min to 60 min.

11. The apparatus according to any one of claims 8-10, characterized in that, The device satisfies any one of the following conditions A to J: A. The liquid includes at least one of water, inorganic solution, and organic solution; B. The liquid includes at least one of a salt solution and an acid solution; C. The liquid comprises at least one of the following: aromatic hydrocarbon organic solutions, aliphatic hydrocarbon organic solutions, alicyclic hydrocarbon organic solutions, halogenated hydrocarbon organic solutions, alcohol organic solutions, ether organic solutions, ester organic solutions, ketone organic solutions, pyridine organic solutions, phenolic organic solutions, nitrile organic solutions, and sulfone organic solutions; D. The liquid includes acetonitrile, N,N Dimethylformamide, dimethyl sulfoxide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, cyclohexanone, toluenecyclohexanone, chlorobenzene, dichlorobenzene, dichloromethane, methanol, ethanol, 1 Propanol, 2 Propanol, 1 Butanol, 2 At least one of the following: butanol, pentanol, diethyl ether, propylene oxide, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, acetone, methyl butyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, pyridine, phenol, styrene, perchloroethylene, trichloroethylene, ethylene glycol ether, and triethanolamine; E. The liquid comprises at least one of the following: hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydrobromic acid, hydroiodic acid, boric acid, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, succinic acid, maleic acid, tartaric acid, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid, valeric acid, hexanoic acid, decanoic acid, stearic acid, palmitic acid, acrylic acid, ascorbic acid, and malic acid; F. The stirring speed of the stirring device is from 200 rpm to 5000 rpm; G. The pressure inside the container is 0.5 MPa to 4 MPa; H. The gas includes at least one of air, nitrogen, oxygen, carbon dioxide, ozone, nitric oxide, nitrogen dioxide, helium, neon, argon, krypton, xenon, and radon; I. The particle size of the nanobubbles is 2 nm to 15 nm; the median particle size of the nanobubbles is 9 nm to 12 nm; J. The absolute value of the zeta potential of the liquid containing the nanobubbles decreased by ≤5 mV after one month of storage.

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