CN100383049C - Method for growing nanorod zinc oxide by hydrothermal decomposition - Google Patents

Abstract

The present invention discloses a method for growing nano-rod shaped zinc oxide by hydrothermal decomposition. The method comprises the following steps that concentrated ammonia is dripped into zinc chloride solution to be thoroughly stirred, the pH value of the solution is adjusted between 9 to 11, and thus, Zn(NH 3)4<2+> is generated; the solution is sealed and then processed with ultrasonic; a cleaned substrate is inserted in the solution and the solution is sealed again; then the sealed solution is placed in the atmosphere at the temperature of 80 to 98 DEG C for still standing; the substrate is taken out, flushed with deionized water and naturally aired, and nano-rod shaped zinc oxide is obtained on the surface of the substrate. The present invention has the advantages that only the zinc chloride and the concentrated ammonia are adopted; compared with the similar methods for preparing nano-structural aqueous solution, the amount of chemical reagents adopted by the present invention is reduced; the preparation process is further simplified; the preparation cost is lowered; the ionic species in the solution and the unfavorable influencing factors are reduced; the sample purity is enhanced; the method is convenient, the nano-rod shaped structure with uniform distribution in large area is obtained, etc.

Description

Method for growing nanorod zinc oxide by hydrothermal decomposition

technical field

The invention relates to a preparation method of nano-scale zinc oxide, in particular to a method for hydrothermally decomposing and growing nano-rod type zinc oxide.

Background technique

Zinc oxide is a wide band gap semiconductor with a band gap of 3.37eV. It is precisely because of its special energy band structure, and at the same time, the one-dimensional nanostructured zinc oxide has a higher surface rate, greater mechanical strength and stable chemical properties, so the one-dimensional nanostructured zinc oxide is used in photoelectric switches, high-efficiency photon Devices, near-ultraviolet lasers, gas/liquid sensors, and flat panel displays will have good application prospects.

At present, the preparation methods of one-dimensional nano-zinc oxide structure include gas-phase synthesis method and liquid-phase synthesis method. Gas-phase synthesis methods include chemical vapor deposition, magnetron sputtering, spray pyrolysis, pulsed laser deposition, atomic layer epitaxy and molecular beam epitaxy, etc.; liquid-phase synthesis methods include sol-gel methods, hydrolysis methods, Inverse emulsion method, precipitation method and chemical deposition method. In comparison, the gas phase method has high reaction temperature, complicated equipment, high cost and low efficiency. At the same time, the liquid phase method has low reaction temperature, low cost and high efficiency, and is suitable for the preparation of industrialized large-area uniform membranes.

Contents of the invention

The invention provides a method for preparing the hydrothermal decomposition and growth nanorod type zinc oxide with low cost and high product purity.

The present invention adopts following technical scheme:

A method for hydrothermally decomposing and growing nanorod type zinc oxide:

The first step: add concentrated ammonia water with a mass percentage concentration of 25% dropwise into a zinc chloride solution with a concentration of 0.08-0.15M and fully stir to adjust the pH value of the solution between 9 and 11, thereby generating Zn(NH ₃ ) ₄ ²⁺ ;

The second step: seal the above solution and use ultrasonic treatment for 25 to 35 minutes;

Step 3: Insert the cleaned substrate into the solution and seal the solution again, and then place the sealed solution in an environment of 80-98° C. for 45-70 minutes;

Step 4: Take out the substrate, rinse it with deionized water and dry it naturally to obtain nanorod-type zinc oxide on the surface of the substrate.

Compared with prior art, the present invention has following advantage:

1. The present invention has only adopted zinc chloride and concentrated ammonia water, reduces the chemical reagent that adopts than similar preparation nanostructure aqueous solution method. On the one hand, the preparation process is further simplified and the preparation cost is further reduced; on the other hand, the ion species in the solution are reduced, adverse influencing factors are reduced, and the sample purity is also improved.

2. The substrate used in the present invention is not particularly limited. When the metal substrate is used, it provides convenience for various electrical measurements of the nanostructure thin film. In addition, the nano-zinc oxide structure grown on the metal substrate is more conducive to making various sensors and other devices.

3. The sample is grown on the side of the inclined substrate facing the bottom of the solution, and a large area of uniformly distributed nanorod structure can be obtained.

4. In the technical scheme of the present invention, zinc chloride and ammonia are dissolved in deionized water according to a certain concentration, and then the solution is pretreated with ultrasonic waves, and then the cleaned substrate is put into the solution and the solution is closed, and finally Putting the airtight container into an oven at 80-98° C. and standing still for 45-70 minutes can obtain the zinc oxide having directional and densely arranged crystals in the form of nanorods. The obtained tower-like structures had an average diameter of 500 nm and an average length of 5 μm.

Description of drawings

Fig. 1 is the scanning electron microscope (SEM) image that is obtained zinc oxide by embodiment 1

FIG. 2 is a scanning electron microscope (SEM) image (enlarged) of zinc oxide obtained in Example 1. FIG.

Fig. 3 is the X-ray diffraction (XRD) image that obtains zinc oxide by embodiment 1

Detailed ways:

The following implementation examples are further illustrations of the present invention, rather than limiting the scope of the present invention.

Example 1

1. Selection and treatment of the substrate: first scrub the wide strip copper substrate with acetone, and then ultrasonically clean it with acetone and deionized water for 15 minutes each;

2. Preparation of film growth solution: 3ml of concentrated ammonia water with a mass ratio of 25% was added dropwise to 40ml of a 0.12M zinc chloride solution and fully stirred; the solution was placed in a glass bottle with a screw cap.

3. Treatment of film growth solution: Seal the above solution and use ultrasonic treatment for 25 minutes;

4. Insert the cleaned copper substrate obliquely into the solution and seal the solution again. Immediately thereafter, the closed container was placed in an oven at 94° C. for 60 minutes. The substrate was taken out and rinsed with deionized water and dried naturally. Finally, densely arranged tower-like zinc oxide nanostructures can be obtained on the downward side of the substrate.

The XRD pattern in Figure 3 shows that the obtained sample is zinc oxide crystals without other impurities.

Figures 1 and 2 show that the obtained zinc oxide is in the hexagonal crystal form. The obtained tower-shaped ZnO nanostructures have an average diameter of 500 nm and an average length of 5 μm.

Example 2

1. Selection and treatment of the substrate: first scrub the wide-strip stainless steel substrate with acetone, then ultrasonically clean it with acetone and deionized water for 15 minutes each;

2. Preparation of film growth solution: 2.5 ml of concentrated ammonia water with a mass ratio of 25% was added dropwise to 40 ml of 0.12M zinc chloride solution and fully stirred; the solution was placed in a glass bottle with a screw cap.

3. Treatment of film growth solution: Seal the above solution and use ultrasonic treatment for 35 minutes;

4. Insert the cleaned stainless steel substrate obliquely into the solution and seal the solution again. Immediately thereafter, the closed container was placed in an oven at 96° C. for 70 minutes. The substrate was taken out and rinsed with deionized water and dried naturally. Finally, densely arranged tower-like zinc oxide nanostructures can be obtained on the downward side of the substrate.

Example 3

A method for hydrothermally decomposing and growing nanorod type zinc oxide:

The first step: add concentrated ammonia water with a mass percentage concentration of 25% dropwise into a zinc chloride solution with a concentration of 0.08-0.15M and fully stir to adjust the pH value of the solution between 9 and 11, thereby generating Zn(NH ₃ ) ₄ ²⁺ , this embodiment can choose to drop concentrated ammonia water in 0.08, 0.10, 0.12 or 0.15M zinc chloride solution, and adjust the pH value of the solution to 9, 9.5, 9.7, 10.1 or 11;

The second step: seal the above solution and use ultrasonic treatment for 25 to 35 minutes. In this embodiment, the ultrasonic treatment time is 25, 28, 32 or 35 minutes;

Step 3: Insert the cleaned substrate into the solution and seal the solution again, and then place the sealed solution in an environment of 80-98°C for 45-70 minutes. In this embodiment, the sealed solution can be placed at 90, Stand at 95 or 98°C for 45, 51, 62 or 70 minutes;

Step 4: Take out the substrate, rinse it with deionized water and dry it naturally to obtain nanorod-type zinc oxide on the surface of the substrate.

In this embodiment, the cleaning of the substrate is to scrub the substrate with acetone, followed by ultrasonic cleaning with acetone and deionized water; the sealing of the solution is to place the solution in a glass bottle with a screw cap; Embodiments also tilt or lay the substrate in the solution.

Claims (4)

1. A method for hydrothermally decomposing and growing nanorod type zinc oxide, characterized in that: The first step: add concentrated ammonia water with a mass percentage concentration of 25% dropwise into a zinc chloride solution with a concentration of 0.08-0.15M and fully stir to adjust the pH value of the solution between 9 and 11, thereby generating Zn(NH ₃ ) ₄ ²⁺ ; The second step: seal the above solution and use ultrasonic treatment for 25 to 35 minutes; Step 3: Insert the cleaned substrate into the solution and seal the solution again, and then place the sealed solution in an environment of 80-98° C. for 45-70 minutes; Step 4: Take out the substrate, rinse it with deionized water and dry it naturally to obtain nanorod-type zinc oxide on the surface of the substrate. 2. The method for hydrothermally decomposing and growing nanorod-type zinc oxide according to claim 1, wherein the cleaning of the substrate is to scrub the substrate with acetone, followed by ultrasonic cleaning with acetone and deionized water. 3. The method for hydrothermally decomposing and growing nanorod type zinc oxide according to claim 1, characterized in that the solution is sealed by placing the solution in a glass bottle with a screw cap. 4. The method for growing nanorod-type zinc oxide by hydrothermal decomposition according to claim 1, characterized in that the substrate is placed obliquely or flatly in the solution.

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