Zinc oxide / zinc cobaltate / carbon nitride ternary composite material and preparation method and application thereof
By preparing a ternary composite material of zinc oxide/zinc cobaltate/carbon nitride and introducing a heterogeneous structure through microwave heating and high-temperature calcination, the problems of insufficient utilization of sunlight and recombination of photogenerated electrons and holes in zinc oxide photocatalysts were solved, thereby improving the photocatalytic sterilization efficiency.
Patent Information
- Application Number
- CN202511297416.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-11
- Publication Date
- 2025-12-12
AI Technical Summary
Zinc oxide, as a photocatalyst, has a wide band gap, which makes it difficult to fully utilize solar energy resources. Furthermore, photogenerated electrons and holes are prone to recombination, resulting in low photocatalytic efficiency.
By preparing a ternary composite material of zinc oxide/zinc cobaltate/carbon nitride, a heterostructure was introduced using microwave heating combined with high-temperature calcination to optimize the recombination rate of photogenerated electron-hole pairs and broaden the material's response in the visible light range.
It improves photocatalytic sterilization performance, enhances the utilization of visible light, reduces the recombination rate of photogenerated electron-hole pairs, and improves photocatalytic efficiency.
Smart Images
Figure CN121103345A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photocatalysis technology, and in particular to a zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material, its preparation method, and its application. Background Technology
[0002] Water is the foundation of life and a crucial element for human survival and development. However, in recent years, with the rapid development of industry and daily life, the unreasonable discharge of wastewater has become increasingly rampant, leading to a more severe water pollution problem. Among these issues, the large-scale proliferation and spread of bacteria in water is like a hidden "time bomb," posing a serious threat to human health.
[0003] In the fight against water pollution and the protection of water quality, water treatment technology plays a crucial role. While traditional methods such as ultraviolet disinfection and membrane technology have been important in past water treatment efforts, photocatalytic sterilization technology, as an emerging antibacterial technology, demonstrates unique advantages in terms of environmental friendliness, efficiency, and sustainability. It uses light energy to excite a catalyst to produce highly oxidizing active substances that effectively kill bacteria and viruses in water without causing secondary pollution, bringing new hope to the field of water treatment.
[0004] Among the many types of photocatalysts, zinc oxide, an inorganic semiconductor material, stands out. It possesses numerous remarkable advantages: its high catalytic activity enables it to rapidly generate large amounts of active substances in photocatalytic reactions, efficiently killing bacteria; its wide bandgap semiconductor properties endow it with a unique electronic structure, providing a foundation for photocatalytic reactions; its environmentally friendly characteristics align with the current concept of green development; its multi-mechanism synergistic antibacterial effect can inhibit bacterial growth and reproduction from multiple angles; and its structural tunability allows researchers to optimize and improve it according to different needs.
[0005] However, zinc oxide, as a photocatalyst, still faces several unresolved issues. On one hand, zinc oxide has a relatively wide band gap (approximately 3.37 eV), making it highly sensitive to ultraviolet light. However, ultraviolet light constitutes a very small proportion of the solar spectrum (only about 5%), preventing it from fully utilizing abundant solar resources and significantly limiting its scope and efficiency in practical applications. On the other hand, during photocatalysis, photogenerated electrons and holes within zinc oxide readily recombine. These photogenerated electrons and holes play a crucial role in the photocatalytic reaction and the generation of active substances, but their recombination consumes a significant amount of energy, thus substantially reducing the photocatalytic efficiency of zinc oxide and hindering its further promotion and application in water treatment.
[0006] In view of this, this application aims to provide a zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material, its preparation method and application, in order to better solve the above-mentioned technical problems. Summary of the Invention
[0007] To address the aforementioned issues, this invention provides a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride, its preparation method, and its applications. The preparation method involves a simple microwave heating followed by high-temperature calcination, resulting in a simple process, short preparation time, safety, high efficiency, and no pollution. By introducing a heterostructure, the prepared material effectively reduces the recombination rate of photogenerated electron-hole pairs and broadens its response in the visible light range, thereby improving its photocatalytic sterilization performance.
[0008] The technical solution adopted in this invention is:
[0009] A method for preparing a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride includes the following steps:
[0010] S1. Add zinc salt to deionized water and stir thoroughly until completely dissolved. Then add cobalt salt and stir thoroughly until completely dissolved. Next, add dispersant and stir thoroughly until completely dissolved. Then heat the solution to obtain a solid.
[0011] Specifically, the zinc salt is at least one of zinc chloride, zinc acetate, zinc nitrate, and zinc sulfate, preferably zinc acetate; the cobalt salt is at least one of cobalt chloride, cobalt acetate, cobalt nitrate, and cobalt sulfate, preferably cobalt acetate; and the dispersant is at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide, and hexadecyltrimethylammonium chloride, preferably sodium dodecyl sulfonate.
[0012] S2. The solid from step S1 is washed, dried, thoroughly ground, transferred to a crucible, and then calcined in a muffle furnace to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0013] S3. Add the nitrogen-containing precursor to the ethanol solution and stir thoroughly until completely dissolved. Then add the zinc oxide / zinc cobalt oxide binary composite material, disperse it ultrasonically, and dry it to obtain a solid.
[0014] Specifically, the nitrogen-containing precursor is at least one of dicyandiamide, urea, melamine, and thiourea, preferably urea;
[0015] S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
[0016] Furthermore, in step S1, the molar ratio of zinc salt to cobalt salt is 0.5~1.5:0.1~1.5, preferably 1:1.
[0017] Further, in step S1, the mass ratio of zinc salt to dispersant is 1.5~15:0.1~1.5, preferably 10:1.
[0018] Further, in step S1, the solution is placed in a microwave oven and heated for 0.1 to 1 hour, with a heating power of 200 to 800 W, preferably 700 W.
[0019] Furthermore, in step S2, the calcination temperature in the muffle furnace is 400~600℃, the calcination time is 1~3h, and the heating rate is 5~15℃ / min. Preferably, the calcination temperature is 500℃, the calcination time is 2h, and the heating rate is 10℃ / min.
[0020] Furthermore, in step S3, the mass of added urea is 0.01g to 2g, with a preferred mass of 0.15g.
[0021] Furthermore, in step S3, the ultrasonic power is 200~500W and the ultrasonic time is 5~30 minutes, with the preferred conditions being: ultrasonic power of 300W and ultrasonic time of 10 minutes.
[0022] Furthermore, in step S4, the calcination temperature in the muffle furnace is 400~600℃, the calcination time is 1~5h, and the heating rate is 5~15℃ / min. Preferably, the calcination temperature is 500℃, the calcination time is 2h, and the heating rate is 10℃ / min.
[0023] Based on the same inventive concept, this application also provides a zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material prepared using the above-described preparation method.
[0024] Based on the same inventive concept, this application also provides an application of the above-mentioned zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material in photocatalysis.
[0025] The beneficial effects of this invention are as follows:
[0026] 1. The ternary material preparation method provided by the present invention is a simple microwave heating method combined with high-temperature calcination. The process is simple, the preparation time is short, and it is safe, efficient and pollution-free.
[0027] 2. The zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material provided by the present invention uses zinc oxide as a carrier and, by doping zinc cobalt oxide and carbon nitride, that is, by introducing a heterostructure, effectively optimizes the recombination rate of photogenerated electron-hole pairs, and can adjust the semiconductor band gap, broaden the material's response in the visible light range, thereby improving the performance of photocatalytic sterilization. Attached Figure Description
[0028] Figure 1 These are solid-state ultraviolet diffuse reflectance images of the materials prepared in Examples 1-4 and the comparative examples of this application;
[0029] Figure 2The band gap Eg plots are for the materials prepared in Examples 1-4 and the comparative examples of this application.
[0030] Figure 3 Solid-state fluorescence images of the materials prepared in Examples 1-4 and the comparative examples of this application;
[0031] Figure 4 The graphs show the photocatalytic inactivation performance of the materials prepared in Examples 1-4 and the comparative examples of this application.
[0032] Figure 5 The image shows the EDS spectrum of the material prepared in Example 3 of this application.
[0033] Figure 6 The image shows the C 1s plot of the X-ray photoelectron spectrum of the material prepared in Example 3 of this application.
[0034] Figure 7 The image shows the N1s plot of the X-ray photoelectron spectrum of the material prepared in Example 3 of this application.
[0035] Figure 8 The X-ray photoelectron spectroscopy (XPS) spectra of Zn 2p in the materials prepared in Example 3 and Comparative Example 1 of this application are shown.
[0036] Figure 9 The image shows the Co 2p spectra of the materials prepared in Example 3 and Comparative Example 1 of this application. Detailed Implementation
[0037] To facilitate understanding of the present invention, it will be described more fully below through embodiments, and preferred embodiments are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Any other implementation schemes obtained by modifying or equivalently substituting the technical solutions of the present invention without inventive step are all within the protection scope of the present invention.
[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0039] The numerical values disclosed in the embodiments of this invention are approximate values, not definitive values. Where error or experimental conditions permit, all values within the error range may be included, and the specific numerical values disclosed in the embodiments of this invention are not limited to those specified.
[0040] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0041] Example 1
[0042] This embodiment provides a method for preparing a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride, including the following steps:
[0043] S1. Add 4.3906g of zinc acetate to 100mL of deionized water and stir thoroughly until completely dissolved; then add 4.3906g of cobalt acetate and stir thoroughly until completely dissolved; then add 0.4391g of sodium dodecyl sulfonate and stir thoroughly until completely dissolved; finally, heat the solution in a microwave oven to 60°C with the microwave oven power set to 700W to obtain a solid.
[0044] S2. The solid obtained in step S1 is washed with deionized water and dried at 60°C. After thorough grinding, it is transferred to a crucible and then placed in a muffle furnace for calcination at 500°C for 2 hours at a heating rate of 10°C / min to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0045] S3. Add 0.05g of urea to the ethanol solution and stir thoroughly until completely dissolved; then grind the zinc oxide / zinc cobalt oxide binary composite material obtained in step S2 thoroughly, add 1g, disperse ultrasonically, and dry to obtain a solid;
[0046] S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace at a calcine temperature of 500℃ for 2 hours at a heating rate of 10℃ / min to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
[0047] Example 2
[0048] This embodiment provides a method for preparing a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride, including the following steps:
[0049] S1. Add 4.3906g of zinc acetate to 100mL of deionized water and stir thoroughly until completely dissolved; then add 4.3906g of cobalt acetate and stir thoroughly until completely dissolved; then add 0.4391g of sodium dodecyl sulfonate and stir thoroughly until completely dissolved; finally, heat the solution in a microwave oven to 60°C with the microwave oven power set to 700W to obtain a solid.
[0050] S2. The solid obtained in step S1 is washed with deionized water and dried at 60°C. After thorough grinding, it is transferred to a crucible and then placed in a muffle furnace for calcination at 500°C for 2 hours at a heating rate of 10°C / min to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0051] S3. Add 0.10g of urea to the ethanol solution and stir thoroughly until completely dissolved; then grind the zinc oxide / zinc cobalt oxide binary composite material obtained in step S2 thoroughly, add 1g, disperse ultrasonically, and dry to obtain a solid;
[0052] S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace at a calcine temperature of 500℃ for 2 hours at a heating rate of 10℃ / min to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
[0053] Example 3
[0054] This embodiment provides a method for preparing a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride, including the following steps:
[0055] S1. Add 4.3906g of zinc acetate to 100mL of deionized water and stir thoroughly until completely dissolved; then add 4.3906g of cobalt acetate and stir thoroughly until completely dissolved; then add 0.4391g of sodium dodecyl sulfonate and stir thoroughly until completely dissolved; finally, heat the solution in a microwave oven to 60°C with the microwave oven power set to 700W to obtain a solid.
[0056] S2. The solid obtained in step S1 is washed with deionized water and dried at 60°C. After thorough grinding, it is transferred to a crucible and then placed in a muffle furnace for calcination at 500°C for 2 hours at a heating rate of 10°C / min to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0057] S3. Add 0.15g of urea to the ethanol solution and stir thoroughly until completely dissolved; then grind the zinc oxide / zinc cobalt oxide binary composite material obtained in step S2 thoroughly, add 1g, disperse ultrasonically, and dry to obtain a solid;
[0058] S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace at a calcine temperature of 500℃ for 2 hours at a heating rate of 10℃ / min to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
[0059] Example 4
[0060] This embodiment provides a method for preparing a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride, including the following steps:
[0061] S1. Add 4.3906g of zinc acetate to 100mL of deionized water and stir thoroughly until completely dissolved; then add 4.3906g of cobalt acetate and stir thoroughly until completely dissolved; then add 0.4391g of sodium dodecyl sulfonate and stir thoroughly until completely dissolved; finally, heat the solution in a microwave oven to 60°C with the microwave oven power set to 700W to obtain a solid.
[0062] S2. The solid obtained in step S1 is washed with deionized water and dried at 60°C. After thorough grinding, it is transferred to a crucible and then placed in a muffle furnace for calcination at 500°C for 2 hours at a heating rate of 10°C / min to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0063] S3. Add 1g of urea to the ethanol solution and stir thoroughly until completely dissolved; then grind the zinc oxide / zinc cobalt oxide binary composite material obtained in step S2 thoroughly, add 1g, disperse ultrasonically, and dry to obtain a solid;
[0064] S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace at a calcine temperature of 500℃ for 2 hours at a heating rate of 10℃ / min to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
[0065] Comparative Example 1
[0066] This comparative example provides a method for preparing a zinc oxide / zinc cobalt oxide binary composite material, comprising the following steps:
[0067] S1. Add 4.3906g of zinc acetate to 100mL of deionized water and stir thoroughly until completely dissolved; then add 4.3906g of cobalt acetate and stir thoroughly until completely dissolved; then add 0.4391g of sodium dodecyl sulfonate and stir thoroughly until completely dissolved. Finally, place the solution in a microwave oven and heat it to 60°C. Set the microwave oven power to 700W to obtain a solid.
[0068] S2. The solid from step S1 is washed with deionized water and dried at 60°C. After thorough grinding, it is transferred to a crucible and then placed in a muffle furnace for calcination at 500°C for 2 hours at a heating rate of 10°C / min to obtain a zinc oxide / zinc cobalt oxide binary composite material.
[0069] Comparative Example 2
[0070] This comparative example provides a method for preparing carbon nitride material, including the following steps:
[0071] S1. Place 5g of urea in a muffle furnace and calcine it at a temperature of 500℃ for 2 hours. The heating rate is 10℃ / min to obtain carbon nitride material.
[0072] Photocatalytic sterilization performance test:
[0073] The materials prepared in Examples 1-4 and Comparative Examples 1-2 were used as photocatalysts for performance testing in inactivating Escherichia coli. The specific procedures are as follows:
[0074] Take 5 mL of E. coli bacterial culture and add it to 45 mL of physiological saline. Then add 5 mg of photocatalyst to the above solution and stir well. Before the light irradiation experiment, place the mixture in the dark and stir for 1 hour to reach adsorption equilibrium. Then irradiate with visible light (300W xenon lamp intensity: 176 mW / cm²). ^2 (420nm filter). Take 100 μL of suspension sample periodically and immediately dilute with 900 μL of physiological saline. Then, spread 100 μL of the diluted sample evenly onto nutrient agar. Finally, incubate these nutrient agar dishes at 37°C for 18 hours and observe the number of E. coli colonies.
[0075] See Figure 1 The image shows the solid-state ultraviolet diffuse reflectance spectra of the materials prepared in Examples 1-4 and Comparative Examples 1-2. From... Figure 1 As can be seen, the light absorption range of the materials prepared in the embodiments of this application is wider than that of the materials prepared in the comparative examples, and the absorption intensity in both the ultraviolet and visible light regions is higher than that of the comparative examples. This indicates that the ternary composite material can improve the utilization of visible light and further enhance the photocatalytic inactivation performance of Escherichia coli.
[0076] See Figure 2 The image shows the band gap Eg plots of the materials prepared in Examples 1-4 and Comparative Examples 1-2. From... Figure 2 As can be seen from the examples, the composite material prepared in this application can have its band gap tunable by doping with zinc cobalt oxide and carbon nitride. It is evident that the ternary composite material can optimize the light absorption capacity, thereby making better use of solar energy.
[0077] See Figure 3 The image shows solid-state fluorescence patterns of the materials prepared in Examples 1-4 and Comparative Examples 1-2. From... Figure 3 As can be seen from the examples, the fluorescence intensity of the composite material prepared in this application can be changed by doping with zinc cobalt oxide and carbon nitride. It is evident that the ternary composite material can optimize the recombination rate of photogenerated electron-hole pairs.
[0078] See Figure 4 The image shows the photocatalytic inactivation performance test results of the catalysts prepared in Examples 1-4 and Comparative Examples 1-2 for Escherichia coli. From... Figure 4 As can be seen, the catalysts prepared by Examples 1-4 of this application all have better performance than Comparative Example 2, and the catalyst prepared by Example 3 has the best performance.
[0079] See Figure 5 The image shown is the EDS energy spectrum of the material prepared in Example 3. From... Figure 3 As can be seen from the catalyst prepared by Example 3 of this application, the presence of C and N is demonstrated, proving the possible existence of g-C3N4.
[0080] See Figure 6 The image shows the C 1s spectrum of the X-ray photoelectron spectroscopy (XPS) of the material prepared in Example 3. As shown in the C 1s spectrum, two peaks are present, located at 284.8 eV and 288.3 eV, respectively. The former is attributed to externally contaminated carbon, and the latter to NC=N coordination, which are characteristic peaks of carbon in g-C3N4. See also... Figure 7 The image shown is the N 1s spectrum in the X-ray photoelectron spectroscopy of Example 3. As shown in the N 1s spectrum, the binding energy of N 1s is 399.5 eV, corresponding to sp2 hybridized nitrogen. Figure 6 and Figure 7 The test results further confirmed the presence of g-C3N4 in the composite material.
[0081] See Figure 8 The image shows the Zn 2p spectra in Comparative Example 1 and Example 3. The Zn spectrum in Comparative Example 1 shows two strong peaks at 1021.1 eV and 1044.1 eV, corresponding to the Zn 2p peaks, respectively. 3 / 2 and 2p 1 / 2 2p 3 / 2 and 2p 1 / 2 Both peaks were resolved to two peaks, revealing the presence of Zn in the ZnO / ZnCo2O4 mixture. 2+ Oxidation state. Compared to Comparative Example 1, the 2p oxidation state of Zn in Example 3 is... 3 / 2 and 2p 1 / 2 The binding energies were shifted to 1022.1 eV and 1045.3 eV, respectively.
[0082] See Figure 9 The image shows the Co 2p spectra of the materials prepared in Comparative Example 1 and Example 3. The Co 2p chemical states at 781.4 eV and 796.6 eV are Co 2p, respectively. 3 / 2 and 2p 1 / 2 Co is at 781.2 eV. 3+ 2p 3 / 2 Co at 796.4 eV 3+ 2p 1 / 2 Furthermore, Co is present at 787.0 eV and 802.4 eV, respectively. 2+ 2p3 / 2 and Co 2+ 2p 1 / 2 A weak peak. Compared to Comparative Example 1, the Co 2p peak position in Example 3 showed a certain degree of negative shift: in Co 2p 3 / 2 There is a negative shift of approximately 1.8 eV, from 781.4 eV to 779.6 eV; at Co 2p 1 / 2 There is a negative shift of approximately 2.2 eV, from 796.6 eV to 794.4 eV. After binding with g-C3N4, the binding energy positions of Zn and Co in the ternary complex changed, indicating the presence of a heterostructure in this ternary system.
[0083] In summary, the catalyst provided by this invention, using zinc oxide as a support, effectively improves the recombination rate of photogenerated electron-hole pairs and modulates the semiconductor band gap by doping with zinc cobalt oxide and carbon nitride, i.e., by introducing a heterostructure, thus broadening the material's response in the visible light range. This ternary composite material exhibits excellent performance in photocatalytic sterilization.
[0084] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. A method for preparing a ternary composite material of zinc oxide / zinc cobaltate / carbon nitride, characterized in that, Includes the following steps: S1. Add zinc salt to deionized water and stir thoroughly until completely dissolved. Then add cobalt salt and stir thoroughly until completely dissolved. Add dispersant and stir thoroughly until completely dissolved. Then heat the solution to obtain a solid. S2. The solid obtained in step S1 is washed and dried, ground thoroughly, transferred to a crucible, and then calcined in a muffle furnace to obtain a zinc oxide / zinc cobalt oxide binary composite material. S3. Add the nitrogen-containing precursor to the ethanol solution and stir thoroughly until completely dissolved. Then add the zinc oxide / zinc cobalt oxide binary composite material, disperse it ultrasonically, and dry it to obtain a solid. S4. After thoroughly grinding the solid obtained in step S3, place it in a crucible and then calcine it in a muffle furnace to obtain a ternary composite material of zinc oxide / zinc cobalt oxide / carbon nitride.
2. The preparation method of the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S1, the zinc salt is at least one of zinc chloride, zinc acetate, zinc nitrate, and zinc sulfate; the cobalt salt is at least one of cobalt chloride, cobalt acetate, cobalt nitrate, and cobalt sulfate; and the dispersant is at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide, and hexadecyltrimethylammonium chloride.
3. The method for preparing the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S1, the molar ratio of zinc salt to cobalt salt is 1:0.1 to 1:1.5; the mass ratio of zinc salt to dispersant is 10:0.1 to 2.
4. The preparation method of the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S1, the solution is placed in a microwave oven and heated for 0.1 to 1 hour with a heating power of 200 to 800 W.
5. The method for preparing the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S2, the calcination temperature in the muffle furnace is 400~600℃, the calcination time is 1~3h, and the heating rate is 5~15℃ / min.
6. The method for preparing the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S3, the nitrogen-containing precursor is at least one of dicyandiamide, urea, melamine and thiourea; the mass fraction of the nitrogen-containing precursor added to the ethanol solution is 0.01% to 2%.
7. The method for preparing the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S3, the ultrasonic power is 200~400W and the ultrasonic time is 10 minutes.
8. The method for preparing the zinc oxide / zinc cobaltate / carbon nitride ternary composite material according to claim 1, characterized in that, In step S4, the calcination temperature in the muffle furnace is 400~600℃, the calcination time is 1~3h, and the heating rate is 5~15℃ / min.
9. A zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material prepared using the preparation method according to any one of claims 1-8.
10. The application of the zinc oxide / zinc cobalt oxide / carbon nitride ternary composite material as described in claim 9 in photocatalysis.