Reaction device for narrow-band luminescence indium phosphide quantum dots, and method for producing narrow-band luminescence indium phosphide quantum dots using reaction device

Abstract

Disclosed in the present invention are a reaction device for narrow-band luminescence indium phosphide quantum dots, and a method for producing narrow-band luminescence indium phosphide quantum dots using the reaction device. The reaction device comprises a high gravity device and a photothermal device, wherein the high gravity device comprises a housing, an electric motor, a rotating disk, shear packing, a liquid distributor, a reaction chamber, a packing cover, a gas outlet, a liquid outlet and liquid inlets; and the photothermal device comprises a laser heating device, a circuit and water cooling device, a reflective layer and a laser controller. In the present invention, infrared laser is coupled into a high gravity reactor, and solvent media such as water or organic compounds are used to absorb infrared light and convert same into thermal energy to raise the temperature of the high gravity reactor, so as to initiate a nucleation reaction of a reactant precursor in a "micro-droplet reactor", thereby realizing the controllable growth of quantum dots in the micro-droplet reactor; and then nanoparticles of uniform size are finally obtained by means of controlling the laser irradiation and heating duration.

Description

A reaction apparatus and method for narrowband luminescent indium phosphide quantum dots Technical Field

[0001] This invention relates to the field of quantum dot nanomaterial preparation technology. Specifically, it relates to a reaction apparatus and method for narrowband luminescent indium phosphide quantum dots; more specifically, it relates to a method for preparing InP / ZnSeS / ZnS core-shell quantum dots and a supergravity-coupled photothermal reaction apparatus. Background Technology

[0002] The essence of chemical preparation of indium phosphide (InP) quantum dots lies in achieving precise and controllable collisions, splitting, and rearrangement of 20-200 atoms at the macroscopic reactor scale. This places extremely high demands on the synergy of nanoscale transport and reaction. The hot-injection method is currently the most mature method for preparing InP quantum dots. Using tris(trimethylsilyl)phosphine [abbreviated as (TMS)3P] as the phosphorus source and indium carboxylate as the indium source, InP quantum dots with excellent optical properties can be obtained; however, its mass production is limited. The solvothermal method has advantages in achieving large-scale preparation of InP quantum dots. Using tris(dimethylamino)phosphine [(DMA)3P] as the phosphorus source, InX3 (X = Cl, Br, I) as the indium source, and oleylamine as the solvent, InP nanocrystals of different sizes can be obtained by changing the proportions of different halogen elements. However, existing liquid-phase precipitation combined with solvothermal growth methods are limited by the molecular mixing rate within traditional stirred tank reactors, making it difficult to achieve precise and controllable nucleation and growth of InP quantum dots.

[0003] A hypergravity reactor is a typical intensification device for chemical processes. The liquid medium inside flows in a porous medium under hypergravity conditions hundreds to thousands of times stronger than Earth's gravity field. This process tears the liquid into micron- and even nanometer-sized films, filaments, and droplets (i.e., generating a large number of rapidly renewing "microdroplet reactors"), greatly enhancing molecular diffusion, micro-mixing, and mass transfer processes between molecules of different sizes. Within the hypergravity reactor, the enhanced micro-molecular mixing and mass transfer processes allow for the nucleation and growth of nanocrystals in a micro-uniform and ideal environment, resulting in explosive and uniform nucleation of nanocrystals. This is beneficial for obtaining nanoparticles with small size and narrow distribution. For example, Chinese Patent Application No. 202110642064.1 discloses a method for preparing InP@ZnS core-shell quantum dots using a hypergravity reactor and the resulting InP@ZnS core-shell quantum dots. However, the preparation of InP quantum dots requires external energy to break through the crystal nucleation energy barrier in order to stimulate the nucleation reaction of the precursor. Due to the uneven heat flow in traditional supergravity reactors, it is difficult to achieve explosive and uniform nucleation of InP crystal nuclei in an ideal state, resulting in poor uniformity of product particle size distribution. The full width at half maximum (FWHM) of the emission spectra of the obtained InP quantum dots is all above 50 nm. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide a reaction device for narrowband luminescent indium phosphide quantum dots.

[0005] The second technical problem to be solved by the present invention is to provide a method for producing narrowband luminescent indium phosphide quantum dots using the above-described reaction apparatus.

[0006] To solve the first technical problem mentioned above, the invention adopts the following technical solution:

[0007] A reaction device for narrowband luminescent indium phosphide quantum dots includes a hypergravity device and a photothermal device;

[0008] The hypergravity device includes a shell, a motor, a turntable, shear packing, a liquid distributor, a reaction chamber, a packing cover, a gas outlet, a liquid outlet, and a liquid inlet;

[0009] The motor's output shaft extends through the lower surface of the housing and into the housing, where it is fixedly connected to the turntable; at the same time, a liquid distributor located above the turntable is also fixedly connected to the top of the motor's output shaft.

[0010] The turntable is provided with an annular shearing packing, the top of which is fixedly covered with a packing cap; a hollow reaction chamber is formed between the turntable, the shearing packing, and the packing cap.

[0011] A liquid outlet is provided at the bottom of the shell; a liquid inlet passes through the shell and communicates with the reaction chamber via the packing cover; a gas outlet is provided at the top of the shell;

[0012] The photothermal device includes a laser heating device, a circuit and water cooling device, a reflective layer and a laser controller;

[0013] The reflective layer is disposed on the inner surface of the housing, and an interlayer is provided between the reflective layer and the housing, with circuitry and a water-cooling device disposed within the interlayer; the laser heating device is disposed on the inner surface of the reflective layer, and the laser heating device is connected to the laser controller through the circuitry within the interlayer.

[0014] Preferably, the filler cap is made of a transparent material to allow laser light to pass through as much as possible.

[0015] Preferably, a turntable is fixed on the output shaft of the motor and drives it to rotate.

[0016] Preferably, the laser heating device includes one or more devices, which can be installed or removed as needed.

[0017] Preferably, the laser heating device is a laser with a wavelength of 980-1500nm.

[0018] Preferably, the power of the laser heating device is 20-500W.

[0019] To solve the second technical problem mentioned above, the invention adopts the following technical solution:

[0020] A method for producing narrowband luminescent indium phosphide quantum dots using the above-described reaction apparatus includes the following steps:

[0021] 1) Dissolve indium precursor, zinc precursor and phosphine precursor in organic solvents respectively, and then completely remove water and oxygen at a temperature of 110-130℃. Then, pass them into a supergravity reactor to carry out the reaction to obtain InP quantum dot cores.

[0022] 2) Dissolve zinc salt, sulfur powder, and selenium powder in an organic solvent, and then pass them into the supergravity reactor with the InP quantum dot core to carry out the reaction, and the reaction yields InP / ZnSeS core-shell quantum dots;

[0023] 3) The zinc salt and thiol are then passed into the above InP / ZnSeS core-shell quantum dots to react, and the reaction yields the I reaction mixture;

[0024] 4) After the shell coating is completed, add a poor solvent to the reaction mixture and centrifuge to separate the precipitate, which is the narrow-band luminescent indium phosphide quantum dot.

[0025] Preferably, in step 1), the indium precursor is one of indium iodide, indium bromide, and indium chloride.

[0026] Preferably, in step 1), the zinc precursor is one of zinc iodide, zinc bromide, and zinc chloride.

[0027] Preferably, in step 1), the phosphine precursor is tris(dimethylamino)phosphine or tris(diethylamino)phosphine.

[0028] Preferably, in step 1), the organic solvent is one or more of oleylamine, octadecylamine, hexadecylamine, tetradecylamine, and dodecylamine.

[0029] Preferably, in step 1), the molar ratio of indium ions in the indium precursor to zinc ions in the zinc precursor is 1:1 to 1:10.

[0030] Preferably, in step 1), the molar ratio of indium ions to phosphine precursor in the indium precursor is 1:3 to 1:7.

[0031] Preferably, in step 1), the molar ratio of the indium precursor to the organic solvent is 1:20 to 1:100.

[0032] Preferably, in step 2), the zinc salt is one or more of zinc iodide, zinc bromide, zinc chloride, zinc stearate, zinc oleate, and zinc acetate.

[0033] Preferably, in step 2), the ratio of selenium powder to sulfur powder is 0:1-2:1.

[0034] Preferably, in step 2), the organic solvent is one of oleylamine, 1-octadecene, tri-n-octylphosphine, and tri-n-octylphosphine oxide.

[0035] Preferably, in steps 1 and 2), the molar ratio of indium ions to zinc salt in the indium precursor is 1:3 to 1:10.

[0036] Preferably, in steps 1 and 2), the sum of the molar ratios of indium ions in the indium precursor and the sulfur powder and selenium powder is 1:3 to 1:10.

[0037] Preferably, in steps 1) and 2), the supergravity reactor is a supergravity rotating packed bed reactor; the rotation speed of the supergravity rotating packed bed reactor is 500 rpm-2000 rpm, and the reaction time is 1 s-60 min.

[0038] Preferably, in step 3), the thiol is one of dodecyl thiol, hexadecyl thiol, and octyl thiol.

[0039] Preferably, in steps 1) and 3), the molar ratio of indium ions to thiols in the indium precursor is 1:10 to 1:20.

[0040] Preferably, in step 4), the unsuitable solvent is ethanol or acetone.

[0041] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0042] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1) The hypergravity photothermal coupling reaction system proposed in this invention uses the liquid medium obtained through a hypergravity shearing device as a "microdroplet reactor." Within the hypergravity reactor, the microscopic molecular mixing and mass transfer processes are greatly enhanced, and the nucleation and growth of nanocrystals takes place in a microscopically uniform and ideal environment, enabling explosive and uniform nucleation of nanocrystals, which is beneficial for obtaining nanoparticles with small particle size and narrow distribution. Furthermore, infrared lasers are coupled into the hypergravity reactor, utilizing solvents such as water or organic matter to absorb infrared light and convert it into heat energy, raising its temperature and stimulating the nucleation reaction of reactant precursors within the "microdroplet reactor." This achieves controllable growth of quantum dots within the microdroplet reactor, and by controlling the laser irradiation heating time, uniformly sized nanoparticles are finally obtained.

[0045] 2) At the same time, the present invention connects the vacuum pump and the nitrogen pipeline through a double row of pipes, which can make the entire reaction system carry out under nitrogen protection, ensuring that the reaction system is free of water and oxygen, so that the hypergravity equipment can be used for quantum dot preparation process. Attached Figure Description

[0046] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] Figure 1 is a schematic diagram of the reaction device structure of the narrowband luminescent indium phosphide quantum dots of the present invention;

[0048] Figure 2 is a schematic diagram of the overall structure of the reaction system in an embodiment of the present invention;

[0049] Figure 3 is a schematic diagram of the process for synthesizing quantum dots according to the present invention;

[0050] Figure 4 shows the fluorescence spectra of the InP / ZnSeS / ZnS quantum dots synthesized in Examples 1, 2, and 3;

[0051] Figure 5 shows the X-ray diffraction (XRD) pattern of the InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0052] Figure 6 shows the X-ray photoelectron spectroscopy (XPS) spectrum of the InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0053] Figure 7 shows a transmission electron microscope (TEM) image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 1;

[0054] Figure 8 shows a transmission electron microscope (TEM) image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 2;

[0055] Figure 9 shows a transmission electron microscope (TEM) image of the InP / ZnSeS / ZnS quantum dots synthesized in Example 3;

[0056] Figure 10 shows photographs of the InP / ZnSeS / ZnS quantum dots synthesized in Examples 1, 2, and 3 under sunlight and 365nm excitation light.

[0057] Figure 11 shows the fluorescence spectra of InP / ZnSeS / ZnS quantum dots synthesized under different hypergravity levels in Example 4;

[0058] Figure 12 shows the full width at half maximum (FWHM) and quantum yield (PLQY) of InP / ZnSeS / ZnS quantum dots synthesized under different hypergravity levels in Example 4;

[0059] Figure 13 shows the fluorescence spectrum of the InP / ZnS quantum dots synthesized in Comparative Example 1.

[0060] Figure 14 is a comparison of the quantum yields of the InP / ZnSeS / ZnS quantum dots synthesized in Comparative Example 2.

[0061] Figure 15 shows the fluorescence spectrum of the InP / ZnSeS / ZnS quantum dots synthesized in Comparative Example 3.

[0062] Figure 16 shows the UV-Vis absorption spectrum of the InP quantum dots synthesized in Comparative Example 4.

[0063] Numerical markings: 1-Housing; 2-Motor; 3-Turntable; 4-Shearing packing; 5-Liquid distributor; 6-Reaction chamber; 7-Packing cover; 8-Gas outlet; 9-Liquid outlet; 11-First liquid inlet; 12-Second liquid inlet; 21-Laser heating device; 22-Circuit and water cooling device; 23-Reflective layer; 24-Laser controller. Detailed Implementation

[0064] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0065] For ease of description, the terms "first," "second," etc., used in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0066] Referring to Figures 1 and 2, as one aspect of the present invention, a reaction device for narrowband luminescent indium phosphide quantum dots includes a hypergravity device and a photothermal device.

[0067] The hypergravity device includes a shell 1, a motor 2, a turntable 3, a shearing packing 4, a liquid distributor 5, a reaction chamber 6, a packing cover 7, a gas outlet 8, a liquid outlet 9, and liquid inlets 11 and 12.

[0068] The output shaft of the motor 2 extends through the lower surface of the housing 1 and into the housing 1, where it is fixedly connected to the turntable 3. At the same time, a liquid distributor 5 located above the turntable 3 is also fixedly connected to the top of the output shaft of the motor 2. The liquid distributor 5 is fixed in the center of the reaction chamber and sprays the reaction material into the entire space.

[0069] An annular shearing packing 4 is provided on the turntable 3, and the top of the shearing packing 4 is fixedly covered with a packing cover 7; a hollow reaction chamber 6 is formed between the turntable 3, the shearing packing 4 and the packing cover 7.

[0070] A liquid outlet 9 is provided on the bottom of the housing 1;

[0071] In this invention, there are two liquid inlets, including a first liquid inlet 11 and a second liquid inlet 12. The liquid inlets pass through the housing 1 and the packing cover 7 and communicate with the reaction chamber 6. A gas outlet 8 is provided on the top of the housing 1.

[0072] The photothermal device includes a laser heating device 21, a circuit and water cooling device 22, a reflective layer 23, and a laser controller 24;

[0073] The reflective layer 23 is disposed on the inner surface of the housing 1, and an interlayer is provided between the reflective layer 23 and the housing 1. A circuit and a water cooling device 22 are disposed in the interlayer. The laser heating device 21 is disposed on the inner surface of the reflective layer 23, and the laser heating device 21 is connected to the laser controller 24 through the circuit in the interlayer.

[0074] In some embodiments of the invention, the packing cap is made of a transparent material to allow laser light to pass through as much as possible.

[0075] In some embodiments of the present invention, a turntable is fixed on the output shaft of the motor and drives it to rotate.

[0076] In some embodiments of the present invention, the laser heating device includes one or more devices, which can be installed or removed as needed; the laser heating device uses a laser controller to control the power of laser heating.

[0077] In some embodiments of the present invention, the laser heating device is a laser with a wavelength of 980-1500nm; the laser heating device uses a water cooling system to ensure the normal operating temperature of the laser.

[0078] In some embodiments of the present invention, the power of the laser heating device is 20-500W.

[0079] This invention couples infrared laser light into a hypergravity reactor, utilizing solvents such as water or organic matter to absorb infrared light and convert it into heat energy, raising its temperature and stimulating the nucleation reaction of precursors within the "droplet reactor." Since infrared light heating utilizes the principle of electromagnetic radiation heat transfer, it achieves the purpose of stimulating the reaction through direct heat transfer, thus avoiding energy loss caused by heating air. This not only saves energy but is also fast and efficient. Furthermore, infrared light has a certain penetrating power; the internal and surface solvent media of a certain depth within the "droplet reactor" simultaneously absorb infrared radiation energy, resulting in uniform heating and promoting uniform nucleation and growth of particles within the droplets, which is beneficial for obtaining high-quality nanoparticle products. The hypergravity-coupled photothermal reactor formed by the fusion of hypergravity and photothermal technologies greatly promotes the mass transfer process. The interface reflection and scattering effects of a large number of microdroplets allow for a more uniform distribution of light irradiation throughout the hypergravity reactor cavity, improving the absorption and utilization of light irradiation energy. This solves the problem of traditional hypergravity reactors struggling to achieve uniform heat distribution at high temperatures, and can be used to prepare narrowband luminescent indium phosphide quantum dots with a half-width of less than 50 nm. As a sustainable energy source, the utilization of light energy has attracted close attention from researchers. Photothermal conversion is a ubiquitous energy conversion process in nature and human-developed systems. Due to its potential applications such as photothermal therapy, photothermal conversion has been extensively studied. In recent years, the rapid development of nanotechnology has brought attention to and enabled photothermal conversion at the micro- and nano-scale in numerous fields, where it plays a crucial role. Infrared light heating utilizes the principle of electromagnetic radiation heat transfer to directly transfer heat and achieve the purpose of stimulating the reaction, thus avoiding energy loss caused by heating air. This not only saves energy but is also fast and efficient. Furthermore, infrared radiation has a certain penetrating power. The internal and surface solvent media of the "droplet reactor" at a certain depth simultaneously absorb infrared radiation energy, resulting in uniform heating and promoting uniform nucleation and growth of particles within the droplet. This is beneficial for obtaining high-quality nanoparticle products, as shown in Figure 3.

[0080] The supergravity coupled photothermal reactor, formed by the integration of supergravity technology and photothermal technology, can greatly promote the mass transfer process. The interface reflection and scattering effects of a large number of microdroplets can make the light irradiation more uniformly distributed throughout the supergravity reactor cavity, thereby improving the absorption and utilization of light irradiation energy.

[0081] As another aspect of the present invention, a method for producing narrowband luminescent indium phosphide quantum dots using the above-described reaction apparatus includes the following steps:

[0082] 1) Dissolve indium precursor, zinc precursor and phosphine precursor in organic solvents respectively, and then completely remove water and oxygen at a temperature of 110-130℃. Then, pass them into a supergravity reactor to carry out the reaction to obtain InP quantum dot cores.

[0083] 2) Dissolve zinc salt, sulfur powder, and selenium powder in an organic solvent, and then pass them into the supergravity reactor with the InP quantum dot core to carry out the reaction, and the reaction yields InP / ZnSeS core-shell quantum dots;

[0084] 3) The zinc salt and thiol are then passed into the above InP / ZnSeS core-shell quantum dots to react, and the reaction yields the I reaction mixture;

[0085] 4) After the shell coating is completed, add a poor solvent to the reaction mixture and centrifuge to separate the precipitate, which is the narrow-band luminescent indium phosphide quantum dot.

[0086] In some embodiments of the present invention, in step 1), the indium precursor is one of indium iodide, indium bromide, and indium chloride.

[0087] In some embodiments of the present invention, in step 1), the zinc precursor is one of zinc iodide, zinc bromide, and zinc chloride.

[0088] In some embodiments of the present invention, in step 1), the phosphine precursor is tris(dimethylamino)phosphine or tris(diethylamino)phosphine.

[0089] In some embodiments of the present invention, in step 1), the organic solvent is one or more of oleylamine, octadecylamine, hexadecylamine, tetradecylamine, and dodecylamine.

[0090] In some embodiments of the present invention, in step 1), the molar ratio of indium ions in the indium precursor to zinc ions in the zinc precursor is 1:1 to 1:10.

[0091] In some embodiments of the present invention, in step 1), the molar ratio of indium ions to phosphine precursor in the indium precursor is 1:3 to 1:7.

[0092] In some embodiments of the present invention, in step 1), the molar ratio of the indium precursor to the organic solvent is 1:20 to 1:100.

[0093] In some embodiments of the present invention, in step 2), the zinc salt is one or more of zinc iodide, zinc bromide, zinc chloride, zinc stearate, zinc oleate, and zinc acetate.

[0094] In some embodiments of the present invention, in step 2), the ratio of selenium powder to sulfur powder is 0:1-0:2, preferably.

[0095] In some embodiments of the present invention, in step 2), the organic solvent is one of oleylamine, 1-octadecene, tri-n-octylphosphine, and tri-n-octylphosphine oxide.

[0096] In some embodiments of the present invention, in steps 1 and 2), the molar ratio of indium ions to zinc salt in the indium precursor is 1:3 to 1:10.

[0097] In some embodiments of the present invention, in steps 1 and 2), the sum of the molar ratios of indium ions in the indium precursor and the molar ratios of selenium powder and sulfur powder is 1:3 to 1:10.

[0098] In some embodiments of the present invention, in steps 1) and 2), the supergravity reactor is a supergravity rotating packed bed reactor; the rotation speed of the supergravity rotating packed bed reactor is 500 rpm-2000 rpm, and the reaction time is 1 s-60 min.

[0099] In some embodiments of the present invention, in step 3), the thiol is one of dodecyl thiol, hexadecyl thiol, and octyl thiol.

[0100] In some embodiments of the present invention, in steps 1) and 3), the molar ratio of indium ions to thiols in the indium precursor is 1:10 to 1:20.

[0101] In some embodiments of the present invention, in step 4), the undesirable solvent is ethanol or acetone.

[0102] Example 1

[0103] InP / ZnSeS / ZnS quantum dots were synthesized using the hypergravity photothermal coupling device of the present invention.

[0104] 2.23g indium iodide, 4.90g zinc bromide, and 50ml oleylamine were thoroughly dehydrated and deoxygenated at 120℃ for 60 minutes. The motor and laser heating device were started first, with the rotation speed and temperature set to 1500 r / min and 100℃ respectively. The precursor solution was then introduced into the hypergravity device via a peristaltic pump. The vacuum pump was turned on until the vacuum gauge pressure reached -0.086MPa, and maintained for 5 minutes before nitrogen gas was introduced. This process was repeated three times. Afterward, the laser heating device was adjusted to raise the temperature to 180℃, and the reaction was carried out under hypergravity conditions for 30 minutes to obtain uniformly sized InP quantum dot nuclei.

[0105] Under nitrogen protection, 30g of zinc stearate and 0.43g of selenium powder and 0.35g of sulfur powder dissolved in 10ml of tri-n-octylphosphine were added to 100ml of octadecene at 120°C. The mixture was then introduced into a hypergravity reactor via a peristaltic pump. The temperature was raised to 240°C by adjusting the laser heating device to perform shell coating. The reaction was carried out for 30 minutes to obtain InP / ZnSeS quantum dots.

[0106] 15 ml of dodecyl mercaptan was introduced into a high-gravity reactor via a peristaltic pump and reacted for 10 min to obtain InP / ZnSeS / ZnS quantum dots;

[0107] Collect the effluent solution; add anhydrous ethanol and centrifuge three times to purify it. The precipitate is then ultrasonically dispersed in n-hexane to obtain the final product InP / ZnSeS / ZnS core-shell quantum dot dispersion.

[0108] Figure 4 shows the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots. The emission peak is 529 nm, which is green, with a full width at half maximum (FWHM) of 50 nm and a quantum yield of 71.46%.

[0109] Figure 5 shows the X-ray diffraction (XRD) pattern of the obtained InP / ZnSeS / ZnS core-shell quantum dots, indicating the presence of InP matching peaks and good crystal structure. Figure 6 shows the X-ray photoelectron spectroscopy (XPS) spectrum of the obtained InP@ZnS core-shell quantum dots, showing the presence of In, P, Zn, S, and Se. Figure 7 shows the transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, indicating good dispersion.

[0110] Figure 10(a) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight excitation at 365 nm. It can be seen that the prepared core-shell quantum dots exhibit bright fluorescence.

[0111] Example 2

[0112] Replace the indium and zinc precursors with 1g of indium chloride and 7g of zinc iodide, while keeping the rest of the reaction process and conditions unchanged.

[0113] Figure 4 shows the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots, with an emission peak at 540 nm, exhibiting green light, a full width at half maximum (FWHM) of 47 nm, and a quantum yield of 70.93%. Figure 8 shows a transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, demonstrating good dispersion. Figure 10(b) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight excitation at 365 nm, showing that the prepared core-shell quantum dots exhibit bright fluorescence.

[0114] Example 3

[0115] Example 1 was repeated, except that the zinc precursor was replaced with 3g of zinc chloride, while the rest of the reaction process and conditions remained the same.

[0116] Figure 4 shows the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots. The emission peak is 577 nm, which is yellow, with a full width at half maximum (FWHM) of 44 nm and a quantum yield of 62.25%.

[0117] Figure 9 shows a transmission electron microscope (TEM) image of the obtained InP / ZnSeS / ZnS core-shell quantum dots, which exhibit good dispersion.

[0118] Figure 10(c) is a photograph of the dispersion of the obtained InP / ZnSeS / ZnS core-shell quantum dots under sunlight excitation at 365 nm. It can be seen that the prepared core-shell quantum dots exhibit bright fluorescence.

[0119] Example 4

[0120] Example 1 was repeated, except that the rotation speed of the supergravity rotating packed bed reactor was set to 0 rpm, 500 rpm, 1000 rpm, 1500 rpm, and 2000 rpm, while the rest of the reaction process and conditions remained unchanged.

[0121] Figure 11 shows the emission spectrum of the obtained InP / ZnSeS / ZnS core-shell quantum dots, and Figure 12 shows a comparison of the full width at half maximum (FWHM) and quantum yield of the obtained InP / ZnSeS / ZnS core-shell quantum dots.

[0122] Comparative Example 1

[0123] The indium and zinc precursors were replaced with 1g of indium chloride and 3g of zinc chloride, and InP / ZnS quantum dots were prepared using a hypergravity device that is currently not coupled with a photothermal device. The steps are as follows:

[0124] InP / ZnS quantum dots were synthesized in a hypergravity reactor without a coupled photothermal device. The motor was started and the speed was set to 1500 r / min. The mixed oil-phase precursor of InP core and Zn precursor and the aqueous-phase precursor of sodium sulfide nonahydrate were preheated respectively. The mixture was then introduced into the hypergravity device via a peristaltic pump. The reaction was carried out under hypergravity conditions for 30 min using the heat from the preheated precursors. Samples were taken at intervals and their luminescence properties were tested.

[0125] Figure 13 shows the emission spectrum of the obtained InP / ZnS core-shell quantum dots, with an emission peak of 613 nm, exhibiting orange light, a full width at half maximum (FWHM) of 88 nm, and a quantum yield of 7.38%.

[0126] Comparative Example 2

[0127] Example 1 was repeated, except that the rotation speed of the supergravity rotating packed bed reactor was set to 500 rpm, and the reaction was sampled at different times. The rest of the reaction process and conditions remained the same.

[0128] Figure 14 shows the quantum yield of the obtained InP / ZnSeS / ZnS core-shell quantum dots as a function of time. The quantum dots have the highest quantum yield after 30 min of reaction.

[0129] Comparative Example 3

[0130] Repeat Example 1, except that the rotation speed of the supergravity rotating packed bed reactor is set to 500 rpm, and the ratio of selenium powder to sulfur powder is changed from 0:1 to 2:1.

[0131] Figure 15 shows the fluorescence spectra of the obtained InP / ZnSeS / ZnS core-shell quantum dots. When the ratio is 0.5:1, the obtained InP / ZnSeS / ZnS core-shell quantum dots have the highest quantum yield of 79.86% and the narrowest half-width of 58 nm.

[0132] Comparative Example 4

[0133] Example 1 was repeated, except that the molar ratio of indium ions to phosphine precursor in the indium precursor was changed from 1:3 to 1:7 to synthesize only InP cores.

[0134] Figure 16 shows the UV-Vis absorption spectra of the obtained InP quantum dots. The increasingly less pronounced first exciton peak of the quantum dots with increasing phosphine precursor indicates a deterioration in size uniformity.

[0135] Comparative Example 5

[0136] Example 1 was repeated, except that the molar ratio of indium ions to phosphine precursor in the indium precursor was 1:2, and only InP cores were synthesized.

[0137] The solution obtained at this time is very light in color, indicating that the content of phosphine precursor is too low, making nucleation difficult.

[0138] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A reaction device for narrowband luminescent indium phosphide quantum dots, characterized in that, Including hypergravity devices and photothermal devices; The hypergravity device includes a shell, a motor, a turntable, shear packing, a liquid distributor, a reaction chamber, a packing cover, a gas outlet, a liquid outlet, and a liquid inlet; The motor's output shaft extends through the lower surface of the housing and into the housing, where it is fixedly connected to the turntable; at the same time, a liquid distributor located above the turntable is also fixedly connected to the top of the motor's output shaft. The turntable is provided with an annular shearing packing, the top of which is fixedly covered with a packing cap; a hollow reaction chamber is formed between the turntable, the shearing packing, and the packing cap. A liquid outlet is provided at the bottom of the shell; a liquid inlet passes through the shell and communicates with the reaction chamber via the packing cover; a gas outlet is provided at the top of the shell; The photothermal device includes a laser heating device, a circuit and water cooling device, a reflective layer and a laser controller; The reflective layer is disposed on the inner surface of the housing, and an interlayer is provided between the reflective layer and the housing, with circuitry and a water-cooling device disposed within the interlayer; the laser heating device is disposed on the inner surface of the reflective layer, and the laser heating device is connected to the laser controller through the circuitry within the interlayer.

2. The reaction apparatus for narrowband luminescent indium phosphide quantum dots according to claim 1, characterized in that: The filler cap is made of a transparent material to allow laser light to pass through as much as possible; Preferably, the laser heating device includes one or more devices, which can be installed or removed as needed; Preferably, the laser heating device is a laser with a wavelength of 980-1500nm; Preferably, the power of the laser heating device is 20-500W.

3. A method for producing narrowband luminescent indium phosphide quantum dots using the reaction apparatus described in any one of claims 1 or 2, characterized in that, Includes the following steps: 1) Dissolve indium precursor, zinc precursor and phosphine precursor in organic solvents respectively, and then completely remove water and oxygen at a temperature of 110-130℃. Then, pass them into a supergravity reactor to carry out the reaction to obtain InP quantum dot cores. 2) Dissolve zinc salt, sulfur powder, and selenium powder in an organic solvent, and then pass them into the supergravity reactor with the InP quantum dot core to carry out the reaction, and the reaction yields InP / ZnSeS core-shell quantum dots; 3) The zinc salt and thiol are then passed into the above InP / ZnSeS core-shell quantum dots to react, and the reaction yields the I reaction mixture; 4) After the shell coating is completed, add a poor solvent to the reaction mixture and centrifuge to separate the precipitate, which is the narrow-band luminescent indium phosphide quantum dot.

4. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 1), the indium precursor is one of indium iodide, indium bromide, and indium chloride.

5. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 1), the zinc precursor is one of zinc iodide, zinc bromide, and zinc chloride; Preferably, in step 1), the phosphine precursor is tris(dimethylamino)phosphine or tris(diethylamino)phosphine; Preferably, in step 1), the organic solvent is one or more of oleylamine, octadecylamine, hexadecylamine, tetradecylamine, and dodecylamine.

6. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 1), the molar ratio of indium ions in the indium precursor to zinc ions in the zinc precursor is 1:1 to 1:

10. Preferably, in step 1), the molar ratio of indium ions to phosphine precursor in the indium precursor is 1:3-1:7; Preferably, in step 1), the molar ratio of the indium precursor to the organic solvent is 1:20 to 1:

100.

7. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 2), the zinc salt is one or more of zinc iodide, zinc bromide, zinc chloride, zinc stearate, zinc oleate, and zinc acetate. Preferably, in step 2), the organic solvent is one of oleylamine, 1-octadecene, tri-n-octylphosphine, and tri-n-octylphosphine oxide.

8. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In steps 1 and 2), the molar ratio of indium ions to zinc salt in the indium precursor is 1:3 to 1:

10. Preferably, in steps 1 and 2), the sum of the molar ratios of indium ions in the indium precursor and the sulfur powder and selenium powder is 1:3 to 1:

10. Preferably, in steps 1) and 2), the supergravity reactor is a supergravity rotating packed bed reactor; the rotation speed of the supergravity rotating packed bed reactor is 500 rpm-2000 rpm, and the reaction time is 1 s-60 min.

9. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 3), the thiol is one of dodecyl thiol, hexadecyl thiol, and octyl thiol; Preferably, in steps 1) and 3), the molar ratio of indium ions to thiols in the indium precursor is 1:10 to 1:

20.

10. The method for producing narrowband luminescent indium phosphide quantum dots according to claim 3, characterized in that: In step 4), the unsuitable solvent is ethanol or acetone.

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