A solvothermal preparation method of cubic system tricobalt tetroxide quantum dots
The preparation of cubic cobalt tetroxide quantum dots by a solvothermal method solves the problems of complex preparation methods, high cost and high pollution in the existing technology, and realizes the acquisition of specific crystal structures and low-cost preparation, which is suitable for catalysis, energy storage and sensing fields.
Patent Information
- Application Number
- CN202410178576.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-09
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2044-02-09
AI Technical Summary
Existing technologies lack specific methods for preparing cobalt tetroxide quantum dots with specific crystal structures, and the preparation methods are costly, complex, polluting, and energy-intensive.
A method for preparing cubic cobalt tetroxide quantum dots using a solvothermal method involves mixing a cobalt source, alcohol, polyvinylpyrrolidone, deionized water, and hydrogen peroxide in a specific ratio, reacting the mixture at a constant temperature in a sealed container, and then cooling, washing, and drying to obtain cubic cobalt tetroxide quantum dots.
Cobalt tetroxide quantum dots with a specific crystal structure were obtained. They have high uniformity in particle size and are well dispersed, making them suitable for catalysis, energy storage and sensing. The preparation process is simple, easy and inexpensive, and suitable for industrial mass production.
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Figure CN118005089B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanomaterials, and particularly to a solvothermal preparation method of cubic cobaltosic oxide quantum dots. BACKGROUND
[0002] Cobaltosic oxide quantum dots have a large specific surface area, excellent pseudo-capacitance performance, excellent catalytic performance, and are widely concerned and researched in the fields of supercapacitors, batteries, and catalysis. There are many preparation methods for cobaltosic oxide quantum dots, such as solvothermal synthesis, hydrothermal synthesis, microwave reaction, and thermal decomposition. However, the reported methods have some defects to some extent, such as no preparation method for specific crystal structure of cobaltosic oxide quantum dots, high cost, complexity, pollution, and high energy consumption. SUMMARY
[0003] The present application relates to the technical field of nanomaterials, and particularly to a solvothermal preparation method of cubic cobaltosic oxide quantum dots.
[0004] To achieve the above-mentioned purpose, the present application provides a solvothermal preparation method of cubic cobaltosic oxide quantum dots, comprising the following steps:
[0005] Mixing a cobalt source, alcohol, polyvinylpyrrolidone, deionized water, and hydrogen peroxide in a set proportion to obtain a mixture;
[0006] The mixture is heated to a preset temperature in a sealed container at a preset volume ratio and reacted at a constant temperature for a set time;
[0007] After the reaction is completed, the reaction product is cooled to room temperature and washed, and then dried to obtain cubic cobaltosic oxide quantum dots.
[0008] The cobalt source is one or more of cobalt acetate, cobalt nitrate, cobalt sulfate, and cobalt chloride.
[0009] The alcohol is one or more of methanol, ethanol, ethylene glycol, and glycerol.
[0010] The volume ratio of the volume of the mixture to the volume of the reaction container is (1-4):5.
[0011] The volume ratio of the deionized water to the alcohol is (0-1):19, the volume ratio of the hydrogen peroxide to the alcohol is (0-1):19, and the mass ratio of the polyvinylpyrrolidone to the cobalt source is (0-4):1; the mass / volume ratio of the total mass of the polyvinylpyrrolidone and the cobalt source to the total volume of the alcohol, water and hydrogen peroxide is (1-5) g:160 mL.
[0012] The temperature of the constant-temperature reaction is 100-160 DEG C, and the reaction time is 6-24 h.
[0013] 1. A solvothermal preparation method of cubic system tricobalt tetraoxide quantum dots, the method comprises the following steps: mixing a cobalt source, alcohol, polyvinylpyrrolidone, deionized water and hydrogen peroxide in a certain proportion, heating the mixture to a preset temperature in a sealed reaction container, and performing constant-temperature reaction for more than 6-24 h, then cooling the reaction product to room temperature, washing and drying the reaction product to obtain cubic system tricobalt tetraoxide quantum dots.
[0014] 2. The tricobalt tetraoxide quantum dots prepared by the method can be applied in the fields of catalysis, energy storage and sensing. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.
[0016] Figure 1 is the X-ray diffraction pattern of the tricobalt tetraoxide quantum dots provided in Embodiment 1 of the present application.
[0017] Figure 2 is the transmission electron microscope image of the tricobalt tetraoxide quantum dots provided in Embodiment 1 of the present application.
[0018] Figure 3 is the size distribution diagram of the tricobalt tetraoxide quantum dots provided in Embodiment 1 of the present application.
[0019] Figure 4 is the high-resolution transmission electron microscope image of the tricobalt tetraoxide quantum dots provided in Embodiment 1 of the present application.
[0020] Figure 5is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 2 of the present application.
[0021] Figure 6 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 3 of the present application.
[0022] Figure 7 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 4 of the present application.
[0023] Figure 8 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 5 of the present application.
[0024] Figure 9 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 6 of the present application.
[0025] Figure 10 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 7 of the present application.
[0026] Figure 11 is a transmission electron microscope image of the cobalt tetraoxide quantum dots provided in Embodiment 8 of the present application. DETAILED DESCRIPTION
[0027] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.
[0028] Embodiment 1: A solvothermal preparation method of cubic cobalt tetraoxide quantum dots, the specific steps are as follows:
[0029] 0.25 g of cobalt acetate, 39 mL of ethanol, 0.4 g of polyvinylpyrrolidone, and 1 mL of hydrogen peroxide were mixed uniformly and sealed in a stainless steel reaction kettle with a 100 mL polytetrafluoroethylene inner liner. The volume ratio of the mixture to the volume of the stainless steel reaction kettle was 2:5. The reaction kettle was placed in a heating device and heated to 140°C and kept at a constant temperature for 12 h. After the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobalt tetraoxide quantum dots.
[0030] The X-ray diffraction pattern of the cobalt tetraoxide quantum dots prepared in this embodiment is shown in Figure 1 . From Figure 1It can be seen that the product has good crystallinity, and it matches the PDF #43-1003 card of cubic Co3O4, indicating that the obtained product is cubic Co3O4. In addition, the relatively wide half-peak width reflects that the particle size is small, which is consistent with the transmission electron microscope picture in Figure 2 .
[0031] The transmission electron microscope picture (high magnification picture) of the cobalt oxide quantum dots of this embodiment is shown in Figure 2 . It can be seen that the sample is a quantum dot with uniform size and particle dispersion. The size distribution of the sample is shown in Figure 2 , and the average particle size is about 3.1 nm. Figure 3
[0032] The high-resolution transmission electron microscope picture of the cobalt oxide quantum dots of this embodiment is shown in Figure 4 . It can be seen that the sample is a quantum dot with good crystallinity, which is consistent with the X-ray diffraction pattern in Figure 4 . Figure 1
[0033] Embodiment 2: A solvothermal preparation method of cubic cobalt oxide quantum dots, the specific steps are as follows:
[0034] 0.25 g of cobalt acetate, 39 mL of ethanol and 1 mL of deionized water were uniformly mixed and sealed in a stainless steel reaction kettle with a 100 mL polytetrafluoroethylene inner liner. The volume ratio of the mixture to the volume of the stainless steel reaction kettle was 2:5. The reaction kettle was placed in a heating device and heated to 140°C and kept at a constant temperature for 12 h. After the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobalt oxide quantum dots.
[0035] The cobalt oxide quantum dots obtained in this embodiment were analyzed by X-ray diffraction pattern. It can be seen that the product has good crystallinity, and it matches the PDF #43-1003 card of cubic Co3O4, indicating that the obtained product is cubic Co3O4.
[0036] The transmission electron microscope picture of the cobalt oxide quantum dots of this embodiment is shown in Figure 5 . It can be seen that the sample is a quantum dot with uniform size and particle dispersion. The size distribution of the sample is shown in Figure 5 , and the average particle size is about 3.1 nm.
[0037] Embodiment 3: A solvothermal preparation method of cubic cobalt oxide quantum dots, the specific steps are as follows:
[0038] Mix 0.25 g cobalt acetate, 39 mL ethanol, 0.4 g polyvinylpyrrolidone and 1 mL deionized water uniformly in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene inner container, and the volume ratio of the mixture to the volume of the stainless steel reaction kettle is 2:5. Place the reaction kettle in a heating device and heat to 140°C and keep constant temperature for 12 h. After the reaction is completed, cool the reaction product to room temperature, wash with anhydrous ethanol and deionized water, and then freeze-dry to obtain cobalt trioxide quantum dots.
[0039] The cobalt trioxide quantum dots obtained in this example are analyzed by X-ray diffraction pattern, and it is found that the product has good crystallinity, and it matches the PDF #43-1003 card of cubic Co3O4, indicating that the product is cubic Co3O4.
[0040] The transmission electron microscope image of the cobalt trioxide quantum dots of this example is shown in Figure 6 It can be seen that the sample is a quantum dot with uneven size, but the quantum dots are relatively dispersed. Figure 6
[0041] Example 4: A solvothermal preparation method of cubic cobalt trioxide quantum dots, the specific steps are as follows:
[0042] Mix 0.25 g cobalt acetate, 39 mL ethanol, 0.4 g polyvinylpyrrolidone and 1 mL deionized water uniformly in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene inner container, and the volume ratio of the mixture to the volume of the stainless steel reaction kettle is 2:5. Place the reaction kettle in a heating device and heat to 140°C and keep constant temperature for 12 h. After the reaction is completed, cool the reaction product to room temperature, wash with anhydrous ethanol and deionized water, and then freeze-dry to obtain cobalt trioxide quantum dots.
[0043] The cobalt trioxide quantum dots obtained in this example are analyzed by X-ray diffraction pattern, and it is found that the product has good crystallinity, and it matches the PDF #43-1003 card of cubic Co3O4, indicating that the product is cubic Co3O4.
[0044] The transmission electron microscope image of the cobalt trioxide quantum dots of this example is shown in Figure 7 It can be seen that the sample is a quantum dot with uneven size, but the quantum dots are relatively dispersed. Figure 7
[0045] Example 5: A solvothermal preparation method of cubic cobalt trioxide quantum dots, the specific steps are as follows:
[0046] Cobalt acetate 0.25 g, ethanol 38 mL, polyvinylpyrrolidone 0.4 g and deionized water 2 mL were mixed uniformly and sealed in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene inner container, the volume ratio of the mixture to the volume of the stainless steel reaction kettle was 2:5, the reaction kettle was placed in a heating device and heated to 140°C and kept at constant temperature for 12 h, after the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobalt trioxide quantum dots.
[0047] The cobalt trioxide quantum dots obtained in this example were analyzed by X-ray diffraction pattern, and it was found that the product had good crystallinity, and it matched the PDF #43-1003 card of cubic Co3O4, indicating that the product was cubic Co3O4.
[0048] The transmission electron microscope image of the cobalt trioxide quantum dots of this example is shown in Figure 8 From Figure 8 It can be seen that the sample is a quantum dot with uniform size, the average particle size is about 4.0 nm, and the quantum dots are relatively dispersed.
[0049] Example 6
[0050] Cobalt acetate 0.25 g, ethanol 38 mL, polyvinylpyrrolidone 0.4 g and deionized water 2 mL were mixed uniformly and sealed in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene inner container, the volume ratio of the mixture to the volume of the stainless steel reaction kettle was 2:5, the reaction kettle was placed in a heating device and heated to 140°C and kept at constant temperature for 12 h, after the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobalt trioxide quantum dots.
[0051] The cobalt trioxide quantum dots obtained in this example were analyzed by X-ray diffraction pattern, and it was found that the product had good crystallinity, and it matched the PDF #43-1003 card of cubic Co3O4, indicating that the product was cubic Co3O4.
[0052] The transmission electron microscope image of the cobalt trioxide quantum dots of this example is shown in Figure 9 From Figure 9 It can be seen that the sample is a quantum dot with uniform size, the average particle size is about 4.0 nm, and the quantum dots are relatively dispersed.
[0053] Example 7: Cobalt acetate, cobalt nitrate, cobalt sulfate and cobalt chloride, ethanol and hydrogen peroxide were mixed uniformly and sealed in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene liner, the volume ratio of the mixture to the volume of the stainless steel reaction kettle was 4:5, the reaction kettle was placed in a heating device and heated to 160℃ and kept at constant temperature for 12 h, after the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobaltosic cobalt quantum dots. The mass of cobalt acetate was 0.21 g, the mass of cobalt acetate was 0.01 g, the mass of cobalt nitrate was 0.01 g, the mass of cobalt sulfate was 0.01 g, the mass of cobalt chloride was 0.01 g, the volume of ethanol was 78 mL, and the volume of hydrogen peroxide was 2 mL.
[0054] The transmission electron microscope image of the cobaltosic cobalt quantum dots of the present example is shown in Figure 2. Figure 10 From Figure 2, it can be seen that the sample is a quantum dot with uniform size. Figure 10
[0055] Example 8: Cobalt acetate, methanol, ethanol, ethylene glycol, glycerol and deionized water were mixed uniformly and sealed in a stainless steel reaction kettle lined with a 100 mL polytetrafluoroethylene liner, the volume ratio of the mixture to the volume of the stainless steel reaction kettle was 1:5, the reaction kettle was placed in a heating device and heated to 100℃ and kept at constant temperature for 24 h, after the reaction was completed, the reaction product was cooled to room temperature, washed with anhydrous ethanol and deionized water, and then freeze-dried to obtain cobaltosic cobalt quantum dots. The mass of cobalt acetate was 0.25 g, the volume of ethanol was 18 mL, the volume of methanol was 0.25 mL, the volume of ethanol was 0.25 mL, the volume of ethylene glycol was 0.25 mL, the volume of glycerol was 0.25 mL, and the volume of deionized water was 1 mL.
[0056] The transmission electron microscope image of the cobaltosic cobalt quantum dots of the present example is shown in Figure 2. Figure 11 From Figure 2, it can be seen that the sample is a quantum dot with uniform size. Figure 11
[0057] In summary, the present application provides a solvothermal preparation method of cubic cobaltosic cobalt quantum dots, which mixes cobalt source, alcohol, polyvinylpyrrolidone, deionized water and hydrogen peroxide in a certain proportion, heats to a preset temperature in a sealed reaction container, and keeps constant temperature for 6-24 h or more, then cools the reaction product to room temperature after the reaction is completed, and dries to obtain cobaltosic cobalt quantum dots with a specific crystal structure. The amount of hydrogen peroxide will affect the size and uniformity of the cubic cobaltosic cobalt quantum dots, and the optimal preparation conditions of Example 1 obtain cobaltosic cobalt quantum dots with small particle size, high size uniformity and good particle dispersion.
[0058] The above disclosed are only some embodiments of the present application, and cannot be used to limit the scope of the present application. Those skilled in the art can understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made to the present application according to the claims, still belong to the scope of the present application.
Claims
1. A solvothermal preparation method of cubic cobaltosic oxide quantum dots, characterized in that, The method comprises the following steps: mixing a cobalt source, alcohol, polyvinylpyrrolidone, deionized water and hydrogen peroxide in a set proportion to obtain a mixture; heating the mixture to a preset temperature in a sealed container and keeping the temperature constant for a set time; after the reaction is completed, the reaction product is cooled to room temperature and washed, and then dried to obtain cubic system cobalt tetraoxide quantum dots; the volume ratio of the volume of the mixture to the volume of the reaction container is (1-4):5; the volume ratio of the deionized water to the alcohol is (0-1):19, the volume ratio of the hydrogen peroxide to the alcohol is (0-1):19, and the mass ratio of the polyvinylpyrrolidone to the cobalt source is (0-4):1; the mass-volume ratio of the total mass of the polyvinylpyrrolidone and the cobalt source to the total volume of the alcohol, water and hydrogen peroxide is (1-5) g:160 mL; the temperature of the constant temperature reaction is 100-160℃, and the reaction time is 6-24h.
2. The method according to claim 1, wherein the cobalt source is one or more of cobalt acetate, cobalt nitrate, cobalt sulfate and cobalt chloride.
3. The method according to claim 1, wherein the alcohol is one or more of methanol, ethanol, ethylene glycol and glycerol.
Citation Information
Patent Citations
Method for preparing cobaltosic oxide nanoparticles by using solvothermal method
CN101838018A