CN108394928B - Preparation method of zinc oxide/zinc stannate core-shell structure heterojunction - Google Patents

Abstract

The invention discloses a preparation method of a zinc oxide/zinc stannate core-shell structure heterojunction. The invention adopts the combination of atomic layer deposition, liquid-phase laser ablation and solvothermal method, and uses flexible fibrous thin metal wire as a substrate to vertically grow a zinc oxide nanorod array on its surface, and then immerse it in a solution by laser ablation. The high-purity metal tin target in the ZnO was obtained, and a highly active solvothermal precursor was obtained, and a ZnO/ZnStan core-shell structure heterojunction was further grown on the ZnO array by solvothermal method. The method adopted in the present invention has the advantages of simple operation, mild reaction conditions, high purity, no impurity elements and no addition of surfactants, etc. The prepared zinc oxide/zinc stannate core-shell structure heterojunction has uniform morphology and size, and has good crystallinity. good. The zinc oxide/zinc stannate core-shell structure heterojunction prepared by the invention can be applied to a flexible fiber-shaped ultraviolet photodetector.

Description

A kind of preparation method of zinc oxide/zinc stannate core-shell heterojunction

technical field

The invention relates to the technical field of preparation of metal oxide semiconductor nanomaterials, in particular to a preparation method of a zinc oxide/zinc stannate core-shell heterojunction.

Background technique

Ultraviolet light detection has caused extensive research and applications in stratospheric ozone monitoring, flame protection, fire protection, and optical communications. The flexible fiber-shaped UV photodetector has the characteristics of flexibility, 360-degree detection, woven and wearable, etc., so it can detect UV light while being worn by the human body, and has a wider application range than flat detectors. At present, the material for preparing flexible fiber-like UV photodetectors is mainly zinc oxide. As a binary metal oxide, zinc oxide has the disadvantage that the band gap is not wide enough (the band gap is about 3.37 eV), and it is difficult to detect ultraviolet light with a shorter wavelength. Compared with binary metal oxide materials, ternary metal oxide zinc stannate has the advantages of high electron mobility, fast electron transfer and fast response speed. At the same time, zinc stannate is an important n-type semiconductor material with a band gap of about 3.64 eV. It can widen the band gap by adjusting the composition ratio and avoid the phase separation caused by doping zinc oxide. The zinc oxide/zinc stannate core-shell heterojunction can broaden the detection range of zinc oxide and achieve a broad spectral response.

At present, there have been some literature reports on the preparation of zinc oxide/zinc stannate heterojunctions. Sunghoon Park et al. (Ceramics International, 2013, 39( ₄ ): 3539-3545) synthesized _Zn2SnO4 nanowires by thermal evaporation using ZnO, _SnO2 and graphite powder as raw materials, and then deposited them on the surface by atomic layer deposition technology ZnO, a zinc stannate (core)/zinc oxide (shell) heterojunction has been prepared and will be used in gas sensors, and the response to NO gas is _five times higher _than that of pure _Zn2SnO4 nanowires . Cheng et al. (ACS Applied Materials & Interfaces, 2014, 6(6):4057-62) by sol-gel method with Zn(NO ₃ ) ₂ .6H ₂ O, SnCl ₂ .2H ₂ O, citric acid and ethylene glycol Zinc oxide/zinc stannate heterojunction nanowires were prepared as raw materials. However, a method combining liquid-phase laser ablation, atomic layer deposition, and solvothermal methods has not yet been seen to fabricate ZnO/ZnStanate core-shell heterojunctions that can be applied to woven and wearable flexible UV light detection.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a zinc oxide/zinc stannate core-shell structure heterojunction.

The technical solution to achieve the purpose of the present invention is: a preparation method of a zinc oxide/zinc stannate core-shell structure heterojunction, which adopts the combination of atomic layer deposition, liquid-phase laser ablation and solvothermal method. The thin metal wire is used as the substrate, and the zinc oxide nanorod array is vertically grown on the surface, and then the high-purity metal tin target immersed in the solution is obtained by laser ablation to obtain a highly active solvothermal precursor. A zinc oxide/zinc stannate core-shell heterojunction was grown. Specifically include the following steps:

Step 1. Use deionized water and absolute ethanol to ultrasonically clean and dry the metal wire respectively;

Step 2, depositing a zinc oxide film on the surface of the metal wire by atomic layer deposition as a seed layer;

Step 3, growing a ZnO nanorod array along the vertical direction on the surface of the seed layer by a solvothermal method;

Step 4, adding the prepared solution into the reaction vessel, placing the tin target in the solution, and immersing the solution on the surface of the target;

Step 5. Adjust the optical path of the pulsed laser beam of the laser, so that the laser beam is focused on the target material below the liquid level of the solvent, select the appropriate laser wavelength, frequency and energy, turn on the pulsed laser, and ablate the tin target in a liquid environment. ; During the laser ablation process, a magnetic stirrer was used to continuously stir the solution until the end of the ablation;

Step 6, take out the tin target, add an alkaline solution to the precursor solution obtained after laser ablation, and adjust the solution to be alkaline; transfer the precursor solution and the zinc oxide nanorod array to a reaction kettle and heat up to a set temperature, and keep warm;

Step 7, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 8. The nanorod array is taken out and cleaned with an organic solvent to obtain a zinc oxide/zinc stannate core-shell structure heterojunction.

Compared with the prior art, the present invention has the following significant advantages: 1) The Sn source-containing solvothermal precursor prepared by liquid-phase laser ablation has ultra-high activity, no other impurity elements are introduced, and the product is pure. 2) The zinc oxide/zinc stannate core-shell structure heterojunction prepared by the method of the present invention has uniform morphology and size, good crystallinity, and broadens the detection range of zinc oxide. At the same time, the flexible fibrous metal wire is used as the substrate, which can be applied to woven and wearable ultraviolet light detection.

Description of drawings

FIG. 1 is an overall view of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 1.

FIG. 2 is a SEM image of the intermediate product ZnO prepared in Invention Example 1. FIG.

3 is a high magnification SEM image of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Invention Example 1.

4 is a cross-sectional SEM image of the ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction of the product prepared in Invention Example 1.

FIG. 5 is the XRD pattern of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 1. FIG.

FIG. 6 is a SEM image of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 2. FIG.

FIG. 7 is the XRD pattern of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 2. FIG.

FIG. 8 is a SEM image of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 3. FIG.

FIG. 9 is a SEM image of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 4. FIG.

10 is a SEM image of the product ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction prepared in Inventive Example 5.

Detailed ways

With reference to the accompanying drawings, a method for preparing a zinc oxide/zinc stannate core-shell structure heterojunction of the present invention comprises the following steps:

Step 1. Ultrasonic cleaning and drying of the flexible fibrous thin metal wire with deionized water and absolute ethanol respectively; the metal wire includes titanium wire or zinc wire, and the diameter is 0.1-1 mm.

Step 2, depositing a zinc oxide film on the surface of the metal wire by atomic layer deposition as a seed layer; the thickness of the zinc oxide film deposited by the atomic layer deposition is 50-200 nm.

Step 3, growing a zinc oxide nanorod array along the vertical direction on the surface of the seed layer by a solvothermal method; the hydrothermal temperature set by the solvothermal method is 90-120° C., and the hydrothermal time is 4-8 h.

Step 4. Add the prepared solution to the reaction vessel, place the tin source target in the solution, and let the solution soak the surface of the target; the prepared solution is a mixture of ethanol, deionized water and hydrogen peroxide, wherein ethanol The volume ratio to deionized water is 0:1 to 1:1, the volume ratio of deionized water to hydrogen peroxide is 15:1 to 120:1, and the tin source target is a high-purity metal tin target with a purity greater than 99.9%.

Step 5. Adjust the optical path of the pulsed laser beam of the laser, so that the laser beam is focused on the tin source target below the solvent level, set the laser wavelength, frequency and energy, turn on the pulsed laser, and burn the tin source target in the reaction vessel. During the laser ablation process, a magnetic stirrer was used to continuously stir the solution until the end of the ablation; the laser was a Nd:YAG solid-state laser, the pulse frequency was 5-10 Hz, the laser wavelength was 1064 nm, and the laser energy was 80-120 mJ. Etching time is 20 to 60 minutes.

Step 6. Take out the tin source target material, add an auxiliary agent to the precursor solution obtained after laser ablation; transfer the precursor solution and the zinc oxide nanorod array to the reaction kettle and heat up to the set temperature, and keep the temperature; the auxiliary agent It is ethanolamine with a concentration of 99.8%, and the volume ratio of ethanolamine to the total solution is 1:6 to 1:12. The set temperature is 140-200°C, and the holding time is 4-15h.

Step 7, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 8. The nanorod array is taken out and washed with an organic solvent to obtain a zinc oxide/zinc stannate core-shell structure heterojunction.

A more detailed description follows:

The method for preparing a zinc oxide/zinc stannate core-shell heterojunction of the present invention adopts the combination of atomic layer deposition, liquid-phase laser ablation and solvothermal method, and uses fine metal wire as the substrate to make a surface ZnO nanorod arrays were grown along the vertical direction, and then a highly active solvothermal precursor was obtained by laser ablation of a high-purity metal tin target immersed in a solution, and ZnO/ZnStanate was grown on the ZnO array by a solvothermal method Core-shell heterojunction. By changing the laser ablation time, the addition amount of deionized water and auxiliary agents (ethanol, hydrogen peroxide, ethanolamine), the reaction temperature, and the reaction time, zinc oxide/zinc stannate core-shell heterojunctions with different sizes and morphologies were obtained. Include the following steps:

Step 1. Take a thin metal wire, ultrasonically clean it with deionized water and absolute ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 50-200 nm on the surface of the thin metal wire. Then, ZnO nanorod arrays were further grown on the surface along the vertical direction by a solvothermal method, and the hydrothermal temperature was set at 90-120 °C, and the hydrothermal time was set at 4-8 h.

Step 2, add the prepared solution in the reaction vessel, place the tin source target in the solution, and make the solution dip the surface of the target; the prepared solution is that the volume ratio of deionized water and hydrogen peroxide is 15: 1～120:1, the tin source target is a high-purity metal tin target with a purity greater than 99.9%.

Step 3. Adjust the optical path of the pulsed laser beam of the laser, so that the laser beam is focused on the target material below the solvent level, select the appropriate laser wavelength, frequency and energy, turn on the pulsed laser, and burn the tin source target material in a liquid environment. During the laser ablation process, a magnetic stirrer was used to continuously stir the solution until the end of the ablation; the laser was a Nd:YAG solid-state laser, the pulse frequency was 5-10 Hz, the laser wavelength was 1064 nm, and the laser energy was 80-120 mJ, The ablation time is 20 to 60 minutes.

Step 4, taking out the tin target, adding an alkaline solution to make the solution alkaline; the alkaline solution is ethanolamine with a concentration of 99.8%, and the volume ratio of ethanolamine to the solution is 1:6-1:12.

Step 5. Transfer the precursor solution in the container to the reaction kettle and heat up to a set temperature, and keep the temperature; the set temperature is 160-180°C, and the holding time is 4-15h.

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. Take out the nanorod array and wash it with an organic solvent or the like. The organic solvent used in the cleaning is ethanol or methanol.

The solvothermal precursor prepared by liquid-phase laser ablation has ultra-high activity, short time required for solvothermal and low temperature, and no other impurity elements are introduced to obtain ZnO/Zn ₂ SnO ₄ core-shell heterogeneity. The junction has high purity and uniform shape and size.

The present invention will be described in further detail below with reference to the embodiments.

Example 1

By combining atomic layer deposition, liquid-phase laser ablation and solvothermal method, ZnO nanorod arrays with uniform morphology and size were synthesized by atomic layer deposition and solvothermal method; then high-purity metal immersed in solution was ablated by laser. A tin target was used to obtain a highly active solvothermal precursor; then a ZnO/ _Zn2SnO4 core _- shell heterojunction with uniform size and morphology was synthesized by a solvothermal method based on a zinc oxide array under mild conditions. Proceed as follows:

Step 1. Take a zinc wire with a diameter of 0.5 mm, ultrasonically clean it with deionized water and anhydrous ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 50 nm on the surface of the metal zinc wire. Then, the ZnO nanorod arrays were further grown on the surface along the vertical direction by solvothermal method, the hydrothermal temperature was set to 90°C, and the hydrothermal time was set to 4h;

Step 2. Add 60 mL of deionized water and 1 mL of hydrogen peroxide into the reaction vessel, place the tin target in the solution, and let the solution soak the surface of the target material;

Step 3, using Nd:YAG solid-state laser, ablating the tin target immersed in the solution for 35min, the pulse frequency is 10Hz, the laser wavelength is 1064nm, and the laser energy is 100mJ;

Step 4, take out the metal tin target, add 7ml of ethanolamine to the solution;

Step 5. Transfer the precursor solution and the zinc oxide nanorod array in the container to the reaction kettle and heat up to 160°C, and keep the temperature for 9h;

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. The nanorod array is taken out and washed with ethanol and deionized water to obtain a ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction array.

The prepared products were characterized and analyzed, as shown in Figures 1-5. The results show that according to the process parameters of Example 1, a ZnO/Zn ₂ SnO ₄ core-shell heterojunction array can be obtained. Figure 1 is an overall view of the prepared ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction. It can be seen that the surface of the obtained material is neat and intact. FIG. 2 is an image of the intermediate product ZnO array. Figures 3 and 4 show that the obtained ZnO/Zn ₂ SnO ₄ core-shell heterojunction has a uniform morphology and size, with a diameter of about 350 nm. XRD patterns show that the core-shell heterojunction is high-purity ZnO/Zn ₂ SnO ₄ .

Example 2

By combining atomic layer deposition, liquid-phase laser ablation and solvothermal method, ZnO nanorod arrays with uniform morphology and size were synthesized by atomic layer deposition and solvothermal method; then high-purity metal immersed in solution was ablated by laser. A tin target was used to obtain a highly active solvothermal precursor; then a ZnO/ _Zn2SnO4 core _- shell heterojunction with uniform size and morphology was synthesized by a solvothermal method based on a zinc oxide array under mild conditions. Proceed as follows:

Step 1. Take a titanium wire with a diameter of 0.1 mm, ultrasonically clean it with deionized water and anhydrous ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 150 nm on the surface of the metal titanium wire. Then, the ZnO nanorod arrays were further grown on the surface along the vertical direction by the solvothermal method. The hydrothermal temperature was set at 95 °C and the hydrothermal time was set at 6 h;

Step 2. Add 60 mL of deionized water and 1.5 mL of hydrogen peroxide into the reaction vessel, place the tin target in the solution, and let the solution soak the surface of the target material;

Step 3. Use a Nd:YAG solid-state laser to ablate the tin target immersed in the solution for 20 minutes, the pulse frequency is 5Hz, the laser wavelength is 1064nm, and the laser energy is 120mJ;

Step 4, take out the tin target, add 10ml of ethanolamine to the solution;

Step 5. Transfer the precursor solution and the zinc oxide nanorod array in the container to the reaction kettle and heat up to 160°C, and keep the temperature for 15h;

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. The nanorod array is taken out and washed with ethanol and deionized water to obtain a ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction array.

The prepared products were characterized and analyzed, as shown in Figure 6 and Figure 7 . The results show that according to the process parameters of Example 2, a core-shell heterojunction nanorod array with a length of about 350 nm can be obtained with uniform morphology and size. The XRD pattern shows that the core-shell heterojunction is ZnO/Zn ₂ SnO ₄ .

Example 3

By combining atomic layer deposition, liquid-phase laser ablation and solvothermal method, ZnO nanorod arrays with uniform morphology and size were synthesized by atomic layer deposition and solvothermal method; then high-purity metal immersed in solution was ablated by laser. A tin target was used to obtain a highly active solvothermal precursor; then a ZnO/ _Zn2SnO4 core _- shell heterojunction with uniform size and morphology was synthesized by a solvothermal method based on a zinc oxide array under mild conditions. Proceed as follows:

Step 1. Take a zinc wire with a diameter of 1 mm, ultrasonically clean it with deionized water and anhydrous ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 200 nm on the surface of the metal zinc wire. Then, the ZnO nanorod arrays were further grown on the surface along the vertical direction by the solvothermal method. The hydrothermal temperature was set at 95 °C and the hydrothermal time was set at 6 h;

Step 2. Add 60 mL of deionized water and 3 mL of hydrogen peroxide into the reaction vessel, place the tin target in the solution, and let the solution soak the surface of the target material;

Step 3, using a Nd:YAG solid-state laser, ablating the tin target immersed in the solution for 60min, the pulse frequency is 10Hz, the laser wavelength is 1064nm, and the laser energy is 110mJ;

Step 4, take out the tin target, add 6ml of ethanolamine to the solution;

Step 5. Transfer the precursor solution and the zinc oxide nanorod array in the container to the reaction kettle and heat up to 200°C, and keep the temperature for 4h;

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. The nanorod array is taken out and washed with ethanol and deionized water to obtain a ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction array.

The prepared products were characterized and analyzed, as shown in Figure 8. The results show that according to the process parameters of Example 3, a core-shell structure heterojunction nanorod array with a length of about 350 nm can be obtained, and the shape and size are uniform.

Example 4

By combining atomic layer deposition, liquid-phase laser ablation and solvothermal method, ZnO nanorod arrays with uniform morphology and size were synthesized by atomic layer deposition and solvothermal method; then high-purity metal immersed in solution was ablated by laser. A tin target was used to obtain a highly active solvothermal precursor; then a ZnO/ _Zn2SnO4 core _- shell heterojunction with uniform size and morphology was synthesized by a solvothermal method based on a zinc oxide array under mild conditions. Proceed as follows:

Step 1. Take a zinc wire with a diameter of 0.5 mm, ultrasonically clean it with deionized water and anhydrous ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 100 nm on the surface of the metal zinc wire. Then, the ZnO nanorod arrays were further grown on the surface along the vertical direction by the solvothermal method. The hydrothermal temperature was set to 100 °C and the hydrothermal time was set to 6 h;

Step 2. Add 60 mL of deionized water and 0.5 mL of hydrogen peroxide into the reaction vessel, place the tin target in the solution, and let the solution soak the surface of the target material;

Step 3. Use a Nd:YAG solid-state laser to ablate the tin target immersed in the solution for 50 minutes, the pulse frequency is 10 Hz, the laser wavelength is 1064 nm, and the laser energy is 80 mJ;

Step 4, take out the tin target, add 8ml of ethanolamine to the solution;

Step 5. Transfer the precursor solution and the zinc oxide nanorod array in the container to the reaction kettle and heat up to 140°C, and keep the temperature for 12h;

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. The nanorod array is taken out and washed with ethanol and deionized water to obtain a ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction array.

The prepared products were characterized and analyzed, as shown in Figure 9. The results show that according to the process parameters of Example 4, a core-shell structure heterojunction nanorod array with uniform morphology and size can be obtained.

Example 5

By combining atomic layer deposition, liquid-phase laser ablation and solvothermal method, ZnO nanorod arrays with uniform morphology and size were synthesized by atomic layer deposition and solvothermal method; then high-purity metal immersed in solution was ablated by laser. A tin target was used to obtain a highly active solvothermal precursor; then a ZnO/ _Zn2SnO4 core _- shell heterojunction with uniform size and morphology was synthesized by a solvothermal method based on a zinc oxide array under mild conditions. Proceed as follows:

Step 1. Take a zinc wire with a diameter of 0.5 mm, ultrasonically clean it with deionized water and absolute ethanol for 30 minutes and dry, and then use atomic layer deposition technology to deposit a zinc oxide film with a thickness of 200 nm on the surface of the metal zinc wire. Then, the ZnO nanorod arrays were further grown on the surface along the vertical direction by the solvothermal method, the hydrothermal temperature was set to 120 °C, and the hydrothermal time was set to 8 h;

Step 2. Add 60 mL of deionized water and 4 mL of hydrogen peroxide into the reaction vessel, place the tin target in the solution, and let the solution soak the surface of the target material;

Step 3. Use a Nd:YAG solid-state laser to ablate the tin target immersed in the solution for 40 min, the pulse frequency is 5 Hz, the laser wavelength is 1064 nm, and the laser energy is 90 mJ;

Step 4, take out the tin target, add 12ml of ethanolamine to the solution;

Step 5. Transfer the precursor solution and the zinc oxide nanorod array in the container to the reaction kettle and heat up to 180°C, and keep the temperature for 6h;

Step 6, after the reaction finishes, the reaction system is cooled to room temperature with the furnace;

Step 7. The nanorod array is taken out and washed with ethanol and deionized water to obtain a ZnO/Zn ₂ SnO ₄ core-shell structure heterojunction array.

The prepared products were characterized and analyzed, as shown in Figure 10. The results show that according to the process parameters of Example 5, a core-shell structure heterojunction nanorod array with uniform morphology and size can be obtained.

Claims (6)

1. a preparation method of zinc oxide/zinc stannate core-shell structure heterojunction, is characterized in that, comprises the following steps: Step 1. Ultrasonic cleaning and drying of flexible fibrous thin metal wires with deionized water and absolute ethanol respectively; Step 2, depositing a zinc oxide film on the surface of the metal wire by atomic layer deposition as a seed layer; Step 3, growing a ZnO nanorod array along the vertical direction on the surface of the seed layer by a solvothermal method; Step 4. Add the prepared solution to the reaction vessel, place the tin source target in the solution, and let the solution soak the surface of the target; the prepared solution is a mixture of ethanol, deionized water and hydrogen peroxide, The volume ratio of ethanol to deionized water is 0:1 to 1:1, the volume ratio of deionized water to hydrogen peroxide is 15:1 to 120:1, and the tin source target is a high-purity metal tin target with a purity greater than 99.9%; Step 5. Adjust the optical path of the pulsed laser beam of the laser to focus the laser beam on the tin source target below the liquid level of the solution, set the laser wavelength, frequency and energy, turn on the pulsed laser, and burn the tin source target in the reaction vessel. During the laser ablation process, a magnetic stirrer was used to continuously stir the solution until the end of the ablation; Step 6, take out the tin source target material, add auxiliary agent to the precursor solution obtained after laser ablation; transfer the precursor solution and the zinc oxide nanorod array to the reaction kettle and heat up to the set temperature, and keep the temperature; The adjuvant is ethanolamine with a concentration of 99.8%, and the volume ratio of ethanolamine to the total solution is 1:6 to 1:12; Step 7, after the reaction finishes, the reaction system is cooled to room temperature with the furnace; Step 8. The nanorod array is taken out and washed with an organic solvent to obtain a zinc oxide/zinc stannate core-shell structure heterojunction. 2 . The method for preparing a zinc oxide/zinc stannate core-shell heterojunction according to claim 1 , wherein the metal wire in step 1 comprises titanium wire or zinc wire, and the diameter is 0.1-1 mm. 3 . 3 . The method for preparing a zinc oxide/zinc stannate core-shell heterojunction according to claim 1 , wherein the thickness of the zinc oxide film deposited by atomic layer deposition in step 2 is 50-200 nm. 4 . 4. The preparation method of a zinc oxide/zinc stannate core-shell heterojunction according to claim 1, wherein the hydrothermal temperature set by the solvothermal method in step 3 is 90-120°C, and the water The heating time is 4-8h. 5. the preparation method of a kind of zinc oxide/zinc stannate core-shell heterojunction according to claim 1, is characterized in that, in step 5, the laser is Nd:YAG solid-state laser, and the pulse frequency is 5～10Hz, and the laser The wavelength is 1064nm, the laser energy is 80-120mJ, and the laser ablation time is 20-60min. 6 . The method for preparing a zinc oxide/zinc stannate core-shell heterojunction according to claim 1 , wherein in step 6, the set temperature is 140-200° C., and the holding time is 4-15 h. 7 .

Images