Colloid-doped quantum dot preparation method based on microreactor

Abstract

The invention belongs to the technical field of quantum dots, and particularly relates to a colloid-doped quantum dot preparation method based on a microreactor. The preparation method comprises the following steps: ultrasonically dispersing cuprous sulfide nanocrystals or silver sulfide nanocrystals in a toluene solution and a methanol solution of cadmium nitrate tetrahydrate to serve as a flow phase A; ultrasonically dispersing tributylphosphine in methylbenzene to serve as a flow phase B; the flow phase A and the flow phase B are mixed through a tee joint at the same flow speed and then enter a micro-reactor reaction area to react, and the Cu-doped CdS quantum dots or the Ag-doped CdS quantum dots are obtained. The doped quantum dots synthesized by the method have uniform size and excellent fluorescence characteristics, and the synthesis efficiency of the colloid doped quantum dots can be remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of quantum dots, relates to the field of preparation of colloid-doped quantum dots, and in particular to a method for preparing colloid-doped quantum dots based on a microreactor. Background Art

[0002] Quantum dots have attracted widespread attention as a new type of material in the field of nanoscience. Quantum dots have the advantages of good photostability, adjustable color, long fluorescence lifetime, etc. They have good development prospects in fluorescent probes and are widely used in the field of optoelectronic devices.

[0003] In particular, colloid-doped quantum dots, which introduce a small amount of heterovalent transition metal elements into the matrix lattice matrix, exhibit large Stokes shift luminescence, enhanced electrical transport, and unique magnetic properties, showing great application potential in the fields of optical devices, biological probes, and information processing. However, the large-scale continuous preparation of high-quality quantum dots limits their commercial application process. Although the traditional one-pot flask reaction method can be used to synthesize quantum dots, the yield is often lower than expected, and quality problems are easily caused when trying to increase the concentration and volume of the reactants, making it difficult to maintain the uniformity of the size and morphology of the quantum dots.

[0004] Chinese patent CN 103887152 B discloses a method for doping semiconductor quantum dots with heterovalent metal ions. The patented method is based on a one-pot method for doping semiconductor quantum dots with heterovalent metal ions. The reaction uses a flask in the laboratory, and the yield is small, which fails to reach the expected level of commercial application. If a larger intermittent reactor (such as a larger flask) is replaced, the intermittent reactor is heated and mixed unevenly, resulting in a long reaction time and many by-products, which will lead to a low yield and poor quality of the product, and the uniformity of the product morphology cannot be ensured. At the same time, the large-scale reaction system is disadvantageous in terms of economy, not only consuming a lot of resources, but also generating a lot of waste, resulting in a huge waste of resources.

[0005] Compared with the traditional one-pot flask reaction method, tubular microreactors are widely used in the synthesis and optimization of nanocrystals, reaction kinetics characterization and other fields due to their advantages such as excellent mixing, high heat and mass transfer, high specific surface area, precise reaction control and continuous production. In addition, the reverse cation exchange reaction was carried out by Ag2S, Cu2S (X = S, Se, etc.) NPs and Cd2O3 connected with phosphine ligands at room temperature. 2+ The reversible cation exchange between the two prepared quantum dots can achieve deep heterovalent doping without changing the size of the quantum dots, thus achieving stable deep site Ag in CdX + or Cu + Doping.

[0006] In view of this, it is necessary to design a microreactor-based colloid-doped quantum dot preparation method to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing colloid-doped quantum dots based on a microreactor, by which the continuous preparation and amplified synthesis of doped quantum dots are realized, and the synthesized doped quantum dots have uniform sizes. This method is conducive to the application of doped quantum dots in optical devices, anti-counterfeiting information processing, etc., and is a preparation method with good application prospects.

[0008] To achieve the above-mentioned object of the invention, the present invention provides a method for preparing colloid-doped quantum dots based on a microreactor, comprising the following steps:

[0009] Cuprous sulfide nanocrystals or silver sulfide nanocrystals are ultrasonically dispersed in a toluene solution and a methanol solution of cadmium nitrate tetrahydrate as a mobile phase A;

[0010] Tributylphosphine was ultrasonically dispersed in a toluene solution as the mobile phase B;

[0011] The fluid phase A and the fluid phase B are mixed at the same flow rate through a three-way connection and then enter the reaction zone of the microreactor for reaction to obtain Cu-doped CdS quantum dots or Ag-doped CdS quantum dots.

[0012] As a further improvement of the present invention,

[0013] A copper precursor is prepared by sodium stearate, n-hexane, hydrated copper chloride and methanol and dispersed in a toluene solution; cuprous sulfide nanocrystals are prepared by the copper precursor, n-dodecyl mercaptan, oleic acid and oleylamine;

[0014] Specifically, sodium stearate powder is added to n-hexane, and a methanol solution of hydrated copper chloride is added. The molar ratio of sodium stearate to hydrated copper chloride is 2:1, the volume ratio of n-hexane to methanol is 1.75:1, and the molar ratio of n-hexane to sodium stearate powder is 107:1; react at 60°C for 3 to 4 hours, wash, centrifuge and dry to prepare a copper precursor; oleic acid and oleylamine are mixed evenly at a volume ratio of 1.66:1, and copper precursor solid powder and n-dodecyl mercaptan are added in sequence, mixed evenly, and reacted at 200°C for 2 hours to 3 hours; wash and centrifuge, and the precipitate is dispersed in a toluene solution.

[0015] A silver precursor is prepared by using silver nitrate, oleic acid, oleylamine and ferric nitrate nonahydrate and dispersed in a toluene solution; and silver sulfide nanocrystals are prepared by using the silver precursor, oleic acid, oleylamine and a sulfur precursor.

[0016] Specifically, oleic acid and oleylamine are mixed in a volume ratio of 1.66:1, and silver nitrate solid powder and ferric nitrate nonahydrate are added in sequence, reacted at 120°C for 2h to 3h, washed and centrifuged, and the precipitate is dispersed in a toluene solution; the silver precursor and toluene are mixed evenly, and a sulfur precursor, oleic acid and oleylamine are added to prepare silver sulfide nanocrystals, which are dispersed in a toluene solution.

[0017] The sulfur precursor solution preparation method is as follows: oleic acid, oleylamine and sulfur powder are heated, stirred and dissolved to obtain a solution, and then dispersed with toluene to obtain a sulfur precursor solution, wherein the volume ratio of oleic acid to oleylamine is 2:1, the molar ratio of oleic acid to sulfur powder is 15.7:1, and the volume of toluene is the sum of the volumes of oleic acid and oleylamine.

[0018] As a further improvement of the present invention, in fluid phase A, the concentration of copper ions is 0.009mol / L-0.013mol / L, the concentration of silver ions is 0.006mol / L-0.012mol / L, the concentration of cadmium ions is 0.069mol / L-0.074mol / L, and the cadmium ions are in excess.

[0019] As a further improvement of the present invention, the concentration of the methanol solution of cadmium nitrate tetrahydrate is 0.1 g / mL to 0.2 g / mL.

[0020] As a further improvement of the present invention, the concentration of the toluene solution of tributylphosphine is 0.033 mol / L to 0.133 mol / L.

[0021] As a further improvement of the present invention, the flow rates of the fluid phase A and the fluid phase B are the same or similar, and the flow rate is 0.2 mL / min to 0.8 mL / min.

[0022] As a further improvement of the present invention, the reaction temperature of the microreactor is 30-70°C.

[0023] As a further improvement of the present invention, the reaction time of the microreactor is 15 to 30 minutes.

[0024] As a further improvement of the present invention, the microreactor includes a first infusion pump, a second infusion pump, a water bath and a cooling collector. The first infusion pump and the second infusion pump are connected to a three-way joint through a polytetrafluoroethylene tube, the three-way joint is connected to the cooling collector through a polytetrafluoroethylene tube, and the three-way joint and the polytetrafluoroethylene tubes before and after the three-way joint are placed in a water bath as a quantum dot preparation area.

[0025] The length of the polytetrafluoroethylene tube in the water bath can be set according to the speed of the flowing phase in the tube. The faster the speed of the flowing phase, the longer the length, and the slower the speed, the shorter the length can be.

[0026] The first infusion pump and the second infusion pump are both double-plunger infusion pumps.

[0027] The present invention uses a microreactor platform in combination with a low-temperature reverse cation exchange strategy to regulate the ion exchange reaction kinetic conditions and process parameters such as flow rate and temperature in the reaction system to achieve high-scale selectivity and high-yield continuous preparation of doped quantum dots.

[0028] The beneficial effects of the present invention are:

[0029] The microreactor-based colloid-doped quantum dot preparation method provided by the present invention achieves low-temperature green continuous preparation of colloid-doped quantum dots by strengthening the ion exchange process and controlling the reaction kinetics, and is suitable for large-scale preparation.

[0030] The colloid-doped quantum dots prepared by the microreactor of the present invention have stable deep-site doping and higher and more stable doping fluorescence.

[0031] The present invention prepares colloid-doped quantum dots through a microreactor platform, thereby realizing continuous preparation and large-scale production of colloid-doped quantum dots. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of a microreactor;

[0033] Figure 2 The fluorescence spectrum and absorption spectrum of the colloid-doped quantum dots prepared in Example 1 of the present invention;

[0034] Figure 3 This is a transmission electron microscope image of the colloid-doped quantum dots prepared in Example 1 of the present invention;

[0035] Figure 4 The fluorescence spectrum and absorption spectrum of the colloid-doped quantum dots prepared in Example 2 of the present invention;

[0036] Figure 5 This is a transmission electron microscope image of the colloid-doped quantum dots prepared in Example 3 of the present invention;

[0037] Figure 6 The fluorescence spectrum and absorption spectrum of the colloid-doped quantum dots prepared in Example 3 of the present invention;

[0038] Figure 7 Comparison of fluorescence spectra of copper-doped quantum dots prepared by one-pot method and microreactor method;

[0039] Figure 8 Comparison of fluorescence spectra of silver-doped quantum dots prepared by one-pot method and microreactor method;

[0040] Figure 1In the figure, 1. the first infusion pump; 2. polytetrafluoroethylene tube; 3. three-way connector; 4. water bath; 5. quantum dot preparation area; 6. the second infusion pump. DETAILED DESCRIPTION

[0041] In order to further understand the present invention, the method for preparing colloid-doped quantum dots based on a microreactor provided by the present invention is described below in conjunction with examples, and the protection scope of the present invention is not limited by the following examples.

[0042] Example 1

[0043] A method for preparing colloid-doped quantum dots based on a microreactor specifically comprises the following steps:

[0044] (1) Preparation of copper precursor:

[0045] Weigh 1.5323g (5mmol) of sodium stearate into a 250mL round-bottom flask, add 70mL of n-hexane, stir for 3min, and then add 40mL of methanol. Dissolve 426.2mg (2.5mmol) of hydrated copper chloride in 10mL of methanol, drop into the above mixed solution, and finally add 10mL of purified water. Stir and react in a 52℃ water bath for 4h, take out the blue copper stearate in the lower layer of the flask, wash twice with ethanol by centrifugation, and dry in a 60℃ oven;

[0046] (2) Preparation of fluid phase A:

[0047] Weigh 157.7mg (0.25mmol) of copper stearate powder in a 10mL reactor, add 5mL of oleic acid and 3mL of oleylamine, stir for 5min, take 0.25mL of n-dodecyl mercaptan and add it to the mixed solution, stir evenly, seal, and place in a 200°C oven for 2.5h, take out the brown cuprous sulfide solution, purify it by centrifugation washing with ethanol, and disperse the resulting precipitate in 8mL of toluene, add 3mL of methanol solution of cadmium nitrate tetrahydrate and fully ultrasonically disperse it evenly as fluid phase A. The concentration of copper ions in the prepared fluid phase A is 0.009mol / L. The preparation process of fluid phase A is only an embodiment, and the amount of cuprous sulfide nanocrystals, toluene and cadmium nitrate used can be proportionally enlarged, and the concentration of copper ions in the fluid phase A can be kept unchanged.

[0048] (3) Preparation of fluid phase B:

[0049] 0.1 mL of tributyl phosphine was dispersed in 6 mL of toluene by ultrasonic dispersion to form fluid phase B. The concentration of tributyl phosphine in fluid phase B was 0.067 mol / L. The preparation process of fluid phase A is only an example, and the amounts of tributyl phosphine and toluene used can be proportionally enlarged, and the concentration of tributyl phosphine in fluid phase A can be kept unchanged.

[0050] (4) Microreactor reaction:

[0051] See also Figure 1 , put the fluid phase A into a blue-capped bottle and connect it to the first infusion pump 1, put the fluid phase B into another blue-capped bottle and connect it to the second infusion pump 6, and connect the infusion pump to the polytetrafluoroethylene tube 2; place the polytetrafluoroethylene tube 2 in the quantum dot preparation area 5, heat the water bath 4 to 60°C, and push the infusion pump at a flow rate of 0.5mL / min so that the solutions in the fluid phases A and B are mixed at the three-way joint 3, and flow through the reaction section composed of a polytetrafluoroethylene coil with an inner diameter of 1mm, an outer diameter of 2mm, and a length of 150cm. The synthesized copper-doped cadmium sulfide quantum dots (CdS:Cu(I)QDs) are collected by a cooling collector at the outlet, after washing and centrifugation. The resulting precipitate is adsorbed on the tube wall, and the precipitate is the prepared CdS:Cu(I)QDs, which are dispersed in 3mL toluene.

[0052] See also Figure 2 As shown, it can be seen that the colloid-doped quantum dots prepared in Example 1 have a good spherical morphology, uniform size, and good monodispersity.

[0053] See also Figure 3 As shown, it can be seen that the fluorescence spectrum and absorption spectrum of the colloid-doped quantum dots prepared in Example 1 achieve a large Stokes shift.

[0054] Example 2

[0055] The difference between this embodiment and embodiment 1 is that in step (3) of this embodiment, the concentration of tributylphosphine ion in the prepared mobile phase B is 0.034 mol / L. The rest of the preparation method and parameters are the same as those in embodiment 1.

[0056] The fluorescence spectrum and absorption spectrum of the copper-doped cadmium sulfide quantum dots prepared in this example are Figure 3 similar.

[0057] Example 3

[0058] A method for preparing colloid-doped quantum dots based on a microreactor specifically comprises the following steps:

[0059] (1) Preparation of silver precursor:

[0060] 20 mL of oleic acid and 20 mL of oleylamine were added to a three-necked flask, stirred evenly, and then 0.34 g of silver nitrate was added, stirred at 30°C for 5 min and N2 was introduced. Subsequently, 0.08 g of ferric nitrate nonahydrate was added, reacted at 120°C for 1 h, purified by centrifugation washing with ethanol, and then dispersed in toluene.

[0061] (2) Preparation of sulfur precursor:

[0062] 2 mmol of sublimed sulfur powder was placed in a single-necked flask containing 5 mL of oleylamine and 10 m of oleic acid. Then, under strong stirring, the mixture was heated at 120 °C in air for 1.5 h to obtain a sulfur precursor;

[0063] (3) Preparation of fluid phase A:

[0064] Take the above 300 μL of silver precursor and the above 3 mL of sulfur precursor and add them to 6 mL of toluene, react at 50 ° C for 1 hour, disperse in 3 mL of toluene after centrifugal washing and purification with ethanol, add 1 mL of methanol solution of cadmium nitrate tetrahydrate and fully ultrasonically disperse it evenly as fluid phase A. The concentration of silver ions in the prepared fluid phase A is 0.012 mol / L. The preparation process of fluid phase A is only an embodiment, and the amount of silver sulfide nanocrystals, toluene and methanol solution of cadmium nitrate tetrahydrate used can be proportionally enlarged to keep the concentration of silver ions in fluid phase A unchanged;

[0065] (4) Preparation of fluid phase B:

[0066] 0.1 mL of tributyl phosphine was dispersed in 6 mL of toluene by ultrasonic dispersion to form a fluid phase B. The concentration of tributyl phosphine in the fluid phase B was 0.067 mol / L. The preparation process of the fluid phase B is only an embodiment, and the amounts of tributyl phosphine and toluene used can be proportionally enlarged, and the concentration of tributyl phosphine ions in the fluid phase B can be kept unchanged.

[0067] (5) Microreactor reaction:

[0068] See also Figure 1 , put the fluid phase A into a blue-capped bottle and connect it to the first infusion pump 1, put the fluid phase B into another blue-capped bottle and connect it to the second infusion pump 6, and connect the infusion pump to the polytetrafluoroethylene tube 2; place the polytetrafluoroethylene tube 2 in the quantum dot preparation area 5, heat the water bath 4 to 60°C, and push the infusion pump at a flow rate of 0.5mL / min so that the solutions in the fluid phases A and B are mixed at the three-way joint 3, and flow through the reaction section composed of a polytetrafluoroethylene coil with an inner diameter of 1mm, an outer diameter of 2mm, and a length of 150cm. Collect the synthesized silver-doped cadmium sulfide quantum dots (CdS:Ag QDs) at the outlet, after washing and centrifugation. The resulting precipitate is adsorbed on the tube wall, and the precipitate is the prepared CdS:Ag QDs, which are dispersed in 3mL toluene.

[0069] See also Figure 5 As shown, it can be seen that the colloid-doped quantum dots prepared in Example 3 have a good spherical morphology, uniform size, and good monodispersity.

[0070] See also Figure 4 As shown, it can be seen that the fluorescence spectrum and absorption spectrum of the colloid-doped quantum dots prepared in Example 3 achieve a large Stokes shift.

[0071] Example 4

[0072] The difference between this embodiment and embodiment 1 is that in step (4) of this embodiment, the flow rate is set to 0.8 mL / min. The rest of the preparation method and parameters are the same as those in embodiment 1.

[0073] The fluorescence spectrum and absorption spectrum of the silver-doped cadmium sulfide quantum dots prepared in this example can be found in Figure 6 .

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 1 is that in step (4), the temperature of the reaction zone is set to room temperature. The rest of the preparation method and parameters are the same as those of Example 1. Under this condition, the ion exchange reaction cannot occur and the colloid-doped quantum dots cannot be synthesized.

[0076] Comparative Example 2

[0077] The difference between this comparative example and Example 1 is that in step (4), the temperature of the reaction zone is set to 80° C. The rest of the preparation method and parameters are the same as those of Example 1. Under this condition, the ion exchange reaction is thorough, no trace amount of metal copper is doped into the lattice, and colloidal doped quantum dots cannot be synthesized.

[0078] Comparative Example 3

[0079] The difference between this comparative example and Example 3 is that the temperature of the reaction zone is set to room temperature. The remaining preparation methods and parameters are consistent with Example 3. Under this condition, the ion exchange reaction cannot occur and the colloid-doped quantum dots cannot be synthesized.

[0080] Comparative Example 4

[0081] The difference between this comparative example and Example 1 is that in step (4), the liquid flow rate is set to 1.0 mL / min. The rest of the preparation method and parameters are consistent with Example 1. Under this condition, the residence time of the reaction is short, and the prepared colloid-doped quantum dots agglomerate.

[0082] Comparative Example 5

[0083] The difference between this comparative example and Example 3 is that the liquid flow rate is set to 1.0 mL / min. The other preparation methods and parameters are consistent with Example 3. Under this condition, the residence time of the reaction is short, and the prepared colloid-doped quantum dots agglomerate.

[0084] Comparative Example 6

[0085] The difference between this comparative example and Example 1 is that in step (4), the liquid flow rate is set to 0.1 mL / min. The remaining preparation methods and parameters are consistent with those of Example 1. Under this condition, the residence time of the reaction is long, the ion exchange reaction is thorough, no trace amount of metal copper is doped into the lattice, and colloid-doped quantum dots cannot be synthesized, and colloid-doped quantum dots cannot be prepared.

[0086] Comparative Example 7

[0087] This comparative example is different from Example 3 in that the liquid flow rate is set to 0.1 mL / min. The remaining preparation methods and parameters are consistent with Example 3. Under this condition, the residence time of the reaction is long, the ion exchange reaction is thorough, no trace amount of metallic silver is doped into the lattice, and colloid-doped quantum dots cannot be synthesized, and colloid-doped quantum dots cannot be prepared.

[0088] Comparative Example 8

[0089] One-pot preparation:

[0090] The preparation of toluene sol of Cu2S nanocrystals is the same as that described in Example 1. The toluene sol of Cu2S nanocrystals and 1 ml of methanol solution of cadmium nitrate tetrahydrate are mixed in a 25 ml round-bottom flask, stirred evenly, and 0.1 ml of tributylphosphine is added, stirred in a water bath at 56°C for 2 h, purified by centrifugation washing with ethanol, and the resulting precipitate is dispersed in 1 ml of toluene;

[0091] The preparation of toluene sol of Ag2S nanocrystals is the same as that described in Example 3. Add 0.2 ml of oleic acid, 0.1 ml of oleylamine and 1 ml of methanol solution of cadmium nitrate tetrahydrate to the toluene sol of Ag2S nanocrystals, stir at room temperature, add 0.1 ml of tributylphosphine (TBP), stir in a water bath at 60°C for 2 h, wash the precipitate by centrifugation with ethanol, and disperse in 5 ml of toluene.

[0092] Figure 7 This is a comparison of the fluorescence spectra of copper-doped quantum dots prepared by one-pot method and microreactor method. Figure 8 The fluorescence spectra of silver-doped quantum dots prepared by one-pot method and microreactor method are compared. Figure 7 and Figure 8 It can be seen that the doped quantum dots prepared by the microreactor method have higher and more stable fluorescence intensity.

[0093] In summary, the present invention provides a method for preparing colloid-doped quantum dots based on a microreactor, a synthesis strategy for preparing colloid-doped quantum dots based on reverse competitive cation exchange reaction, a microreaction synthesis system is designed, and colloid-doped quantum dots are precisely synthesized. Characterization confirms that the colloid-doped quantum dots prepared by this preparation method have excellent optical properties. The preparation efficiency of colloid-doped quantum dots is optimized. The continuous preparation and large-scale production of colloid-doped quantum dots are realized. Colloid-doped quantum dots exhibit large Stokes shift luminescence, enhanced electrical transport, and unique magnetic properties, which are conducive to improving their application in optical devices, biological probes, information processing, and other fields.

[0094] The process parameters (such as temperature, time, etc.) of the present invention can realize the method by taking upper and lower limits and interval values, and the embodiments are not listed one by one here.

[0095] Any contents not described in detail in the present invention can be based on the conventional technical knowledge in the art.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing colloid-doped quantum dots based on a microreactor, the preparation method comprising the following steps: Cuprous sulfide nanocrystals or silver sulfide nanocrystals are ultrasonically dispersed in a toluene solution and a methanol solution of cadmium nitrate tetrahydrate as a mobile phase A; Tributylphosphine was ultrasonically dispersed in a toluene solution as the mobile phase B; The fluid phase A and the fluid phase B are mixed at the same flow rate through a three-way connection and then enter the reaction zone of the microreactor for reaction to obtain Cu-doped CdS quantum dots or Ag-doped CdS quantum dots.

2. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: A copper precursor is prepared by sodium stearate, n-hexane, hydrated copper chloride and methanol and dispersed in a toluene solution; cuprous sulfide nanocrystals are prepared by the copper precursor, n-dodecyl mercaptan, oleic acid and oleylamine; A silver precursor is prepared by using silver nitrate, oleic acid, oleylamine and ferric nitrate nonahydrate and dispersed in a toluene solution; and silver sulfide nanocrystals are prepared by using the silver precursor, oleic acid, oleylamine and a sulfur precursor.

3. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: In the fluid phase A, the concentration of copper ions is 0.009mol / L-0.013mol / L, the concentration of silver ions is 0.006mol / L-0.012mol / L, and the concentration of cadmium ions is 0.069mol / L-0.074mol / L.

4. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The concentration of the toluene solution of tributylphosphine is 0.033 mol / L to 0.133 mol / L.

5. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The concentration of the methanol solution of cadmium nitrate tetrahydrate is 0.1 g / mL to 0.2 g / mL.

6. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The flow rates of the fluid phase A and the fluid phase B are 0.2 mL / min to 0.8 mL / min.

7. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The reaction temperature of the microreactor reaction zone is 30°C to 70°C.

8. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The reaction time of the microreactor reaction zone is 15 minutes to 30 minutes.

9. The method for preparing colloid-doped quantum dots based on a microreactor according to claim 1, characterized in that: The microreactor includes a first infusion pump, a second infusion pump, a water bath and a cooling collector. The first infusion pump and the second infusion pump are connected to a three-way joint through a polytetrafluoroethylene tube, the three-way joint is connected to the cooling collector through a polytetrafluoroethylene tube, and the three-way joint and the polytetrafluoroethylene tubes before and after the three-way joint are placed in a water bath as a quantum dot preparation area.

Images