CN106629824A - Preparation method for hierarchical hollow cubic stannic oxide nanometer particle - Google Patents

Abstract

The invention relates to a preparation method for a hierarchical hollow cubic stannic oxide nanometer particle composed of ultrafine nano-rods and belongs to the technical field of nanometer material preparation. The method comprises the following steps: taking solid cubic zinc hydroxystannate as a precursor, covering a layer of stannic oxide nano-rods on the surface of the zinc hydroxystannate after the hydrothermal reaction for a period of time, and meanwhile, decomposing the inner zinc hydroxystannate, thereby acquiring the hierarchical hollow cubic stannic oxide nanometer particle composed of the ultrafine nano-rods in the shape similar to the shape of zinc hydroxystannate. Compared with the traditional template method, the preparation method has the advantages of low cost, few steps and simple operation; the prepared hollow stannic oxide nanometer particle has an obvious hierarchical structure and a mesoporous structure, is difficult to agglomerate, is excellent in crystallinity and is high in specific surface area; the hierarchical hollow cubic stannic oxide nanometer particle is composed of a large quantity of orderly arrayed nano-rods and the size of the nano-rods is close to the debye length; the air-sensitive characteristic is excellent; and the hierarchical hollow cubic stannic oxide nanometer particle has a potential application value in the field of air-sensitive sensors.

Description

A kind of preparation method of hierarchical hollow cubic tin dioxide nanoparticles

technical field

The invention belongs to the technical field of nanomaterial preparation, and in particular relates to a method for preparing hierarchical hollow cubic tin oxide nanoparticles composed of ultrafine nanorods. This type of hierarchical hollow structure exhibits excellent performance in the field of gas sensors. gas-sensing performance.

Background technique

In recent years, hierarchical hollow structure nanomaterials with various morphologies have received more and more attention in the fields of basic research and practical applications. Its applications include drug delivery, catalysis, gas sensing, clean energy conversion, energy storage, etc. Today, the best way to prepare a well-formed hollow structure consists of coating the desired material on a removable template, or transforming it with preformed particles according to different principles (chemical displacement method, Kirkendall effect, acid-base etching, etc.) generate. Although there are many notable examples of hollow structures being successfully prepared, the hollowing process is usually complex and requires multiple steps. Only a few methods based on Oswald ripening and soft templates can simply prepare hollow structures without hard templates, but the results are usually hollow spherical structures. Considering this aspect, it is still of great value to explore new feasible methods to prepare non-spherical hierarchical hollow structures relatively simply.

Tin dioxide, as an n-type semiconductor with a wide bandgap (Eg=3.6eV, at 300K), has high electrical conductivity and good stability, and is currently the most widely studied and earliest used sensitive material in practice. Moreover, since the absorptivity of tin dioxide in the visible light range is almost zero, the transmittance is extremely high, so it is also widely used in the optical field. With the rapid development of nanotechnology, the research on tin dioxide is not limited to the application of gas-sensing properties and batteries. For example, tin dioxide has great application prospects in waveguide optics, transistors, and optical sensors. With the extensive research of tin dioxide, including thermal evaporation method, laser ablation method, solid-phase synthesis method and solution method, etc., have been used to prepare tin dioxide nanoparticles. In 2009, Xu et al. used crystalline sodium stannate as raw material to synthesize tin dioxide nanorods with a diameter of 90 nm and hollow tin dioxide nanospheres with a diameter of 120 nm by hydrothermal method (Xu, J.Q.; Wang, D.; Qin, L.P.; Yu, W.J.; Pan, Q.Y.Sens.Actuators, B 2009,137,490-495); in 2010, Yin et al. synthesized tin dioxide nanosheets with a thickness of 6nm and a width of 30nm by hydrothermal method using stannous sulfate as raw material Hollow nanospheres composed of (Yin, X.M.; Li, C.C.; Zhang, M.; Hao, Q.Y.; Liu, S.; Chen, L.B.; Wang, T.H.J. Phys.Chem.C 2010, 114, 8084-8088); 2014 In 2010, Liu et al. used crystalline stannous chloride as raw material to synthesize nanoflowers composed of extremely thin tin dioxide nanosheets by using sodium citrate-assisted hydrothermal method (Liu Yang, Jiao Yang, Zhang Zhenglin, Qu Fengyu, Ahmad Uar, and WuXiang, ACS Appl. Mater. Interfaces 2014, 6, 2174-2184). However, the above hydrothermal synthesis methods failed to prepare hierarchical non-spherical hollow nanostructured SnO nanoparticles.

Contents of the invention

The technical problem to be solved by the present invention is that, compared with a spherical structure, due to the lack of a non-spherical template, the lengthy preparation process and the accompanying high cost, and the difficulty in growing the design material on the high-curvature edge of the template, the non-spherical two The preparation of tin oxide is still difficult. To solve this difficulty, several new self-templating methods have successfully prepared various non-spherical SnO2 particles. Such particles are usually composed of random agglomerations of 0-dimensional nano single crystals, but ordered one-dimensional nanorods and two-dimensional nanosheets are rarely seen. However, such nanorods or sheets as structural units to form hollow structures have unique characteristics, such as controllable morphology, anisotropy and ordered porosity due to exposed crystal planes. Therefore, a method for preparing hierarchical hollow cubic tin dioxide nanoparticles composed of ultrafine nanorods with simple operation, excellent product structure and low production cost is provided.

The concrete technical scheme that the present invention takes is as follows:

A preparation method of hierarchical hollow cubic tin dioxide nanoparticles, comprising the following specific steps:

The first step is to prepare a solution containing solid cubic-shaped zinc hydroxystannate nanoparticles, and use the co-precipitation method to mix and stir the aqueous solution containing zinc source, tin source, alkali and surface protection agent at room temperature;

The second step is to move the above solution into the hydrothermal reaction kettle, put it into a constant temperature blast oven, and set the constant temperature of the oven;

In the third step, after a period of hydrothermal reaction, hierarchical hollow cubic tin dioxide nanoparticles composed of ultrafine nanorods are directly generated.

In the first step, the step of preparing a solution containing solid cubic zinc hydroxystannate nanoparticles is: at room temperature, first configure an aqueous solution containing ZnO, NaOH, and CTAB, the concentrations of which are respectively 0.003-0.01 mol/liter of ZnO; ; 0.02-0.04 moles/liter of CTAB; 0.2-0.4 moles/liter of NaOH;

Then configure an aqueous solution containing SnCl4, the concentration of which is 0.1-0.3 mol/liter, add the SnCl4 solution dropwise to the above aqueous solution containing ZnO, NaOH, and CTAB, stir well and let it stand for a while.

In the second and third steps, the mixed solution obtained in the first step is fully stirred and then transferred into a 50ml hydrothermal reaction kettle, and the hydrothermal reaction is carried out at 160-210°C for 8-15h; Centrifugal cleaning with ethanol for 3 times, centrifugation at 6500 rpm for 3-5 minutes, and finally drying at 60°C to obtain hierarchical hollow cube-shaped tin dioxide nanoparticles composed of ultrafine nanorods.

The configuration contains an aqueous solution of SnCl4: dissolve ZnO, NaOH, and CTAB with deionized water, and stir thoroughly.

Dissolve SnCl ₄ in deionized water, then add the SnCl 4 solution dropwise to the aqueous solution containing ZnO, NaOH, and CTAB, stir well and let stand for a period of time.

The time for the full stirring is 5 min.

After the full stirring for 10 min, let stand for 24 h.

The present invention has following benefit:

1. Synthesize tin dioxide nanoparticles with excellent structure, a hollow hierarchical structure composed of one-dimensional nanorods, not easy to agglomerate, anisotropy, large specific surface area and high chemical activity, and a large number of surface contacts between particles. Excellent gas sensitivity performance.

2. The cost is low, all the common chemical experimental drugs are used in the experiment, and the price is low.

3. Simple operation, one-pot process, no need to separate precursors, no template required.

Description of drawings

Figure 1 is a scanning electron micrograph of hierarchical hollow cubic tin dioxide nanoparticles composed of one-dimensional nanorods prepared in Example 1.

Fig. 2 is a transmission electron micrograph of hierarchical hollow cubic tin dioxide nanoparticles composed of one-dimensional nanorods prepared in Example 1.

Fig. 3 is an X-ray diffraction pattern of hierarchical hollow cubic tin dioxide nanoparticles composed of one-dimensional nanorods prepared in Example 1.

Fig. 4 is the sensitivity diagram of the hierarchical hollow cubic tin dioxide nanoparticles composed of one-dimensional nanorods prepared in Example 1 and the hollow spherical tin dioxide nanoparticles compared with it to n-butanol gas.

Figure 5 is a scanned image of hierarchical hollow cube-shaped tin dioxide nanoparticles composed of a mixture of nanosheets and nanorods.

Fig. 6 is a transmission scanning image of hierarchical hollow cube-shaped tin dioxide nanoparticles composed of a mixture of nanosheets and nanorods.

detailed description

A preparation method of hierarchical hollow cubic tin dioxide nanoparticles composed of ultrafine nanorods, the steps are as follows: first, an aqueous solution containing ZnO, NaOH, and CTAB is prepared, and the concentrations are respectively 0.005 mol/liter of ZnO; 0.03 mol /L of CTAB; 0.24 mol/L of NaOH. Then configure the aqueous solution containing SnCl4, and its concentration is 0.12 mol/liter. Add the above SnCl4 solution dropwise to the above aqueous solution containing ZnO, NaOH, and CTAB, stir well and let it stand for a period of time. After the above mixed solution was fully stirred, it was transferred into a 50ml hydrothermal reaction kettle, and reacted hydrothermally at 180°C for 12h. After the reaction, the precipitate obtained was centrifuged three times with deionized water and absolute ethanol respectively (centrifuged at 6500 rpm for 3 minutes). Finally, it was dried at 60° C. to obtain hierarchical hollow cubic tin dioxide nanoparticles composed of ultrafine nanorods. In addition, the above mixed solution was fully stirred and then transferred into a 50ml hydrothermal reaction kettle, and subjected to hydrothermal reaction at 200°C for 12h. After the reaction, the precipitate obtained was centrifuged three times with deionized water and absolute ethanol respectively (centrifuged at 6500 rpm for 3 minutes). Finally, it was dried at 60°C to obtain hierarchical hollow cubic tin dioxide nanoparticles composed of nanosheets and nanorods.

The operation steps of the present invention are mainly divided into three stages: the first step is to prepare a solution containing solid cube-shaped zinc hydroxystannate nanoparticles, and use co-precipitation method to mix and stir at room temperature to contain zinc source, tin source, alkali, surface protection The aqueous solution of the agent is obtained; the second step is to move the above solution into the hydrothermal reaction kettle, put it into the constant temperature blast oven, and set the constant temperature of the oven; the third step, after the hydrothermal reaction for a period of time, directly generate the ultrafine nano Hierarchical hollow cube-shaped SnO nanoparticles composed of rods.

Implementation example 1:

Weigh 17mg of ZnO, 240mg of NaOH, 292mg of CTAB and 210mg of SnCl ₄ , then dissolve ZnO, NaOH and CTAB with 25mL of deionized water and stir for 5min, then dissolve SnCl ₄ with 5ml of deionized water, and then dissolve the SnCl4 solution Add an aqueous solution containing ZnO, NaOH, and CTAB dropwise, stir well for 10 minutes and let it stand for 24 hours, then stir the solution for 5 minutes and then transfer it to a hydrothermal reaction kettle for 12 hours of hydrothermal reaction at 180°C. After the reaction, wash with deionized water and absolute ethanol for three times each, and then dry the precipitate at 60°C in an air atmosphere to collect hierarchical hollow cube-shaped tin dioxide nanoparticles composed of ultrafine nanorods. The scanned picture See attached drawing 1, and see attached drawing 2 for the transmission scanning picture.

The X-ray diffraction pattern of the graded hollow cube-shaped tin dioxide nanoparticles made up of one-dimensional nanorods prepared by implementation example 1 is shown in accompanying drawing 3, and it can be seen that the sample prepared by implementation example 1 only contains a kind of material of tin dioxide and With good crystallinity, the corresponding PDF standard card is JCPDS 41-1445. The gas-sensing ability of the hierarchical hollow cubic tin dioxide nanoparticles composed of one-dimensional nanorods to n-butanol gas was tested, and the test results are shown in Figure 4. It can be seen that the hollow-structure tin dioxide nanoflower particles composed of one-dimensional nanorods have excellent gas-sensing properties for n-butanol gas, and are better than the hollow spherical tin dioxide particles composed of zero-dimensional nanoparticles.

Implementation example 2:

Weigh 17mg of ZnO, 240mg of NaOH, 292mg of CTAB and 210mg of SnCl ₄ , then dissolve ZnO, NaOH and CTAB with 25mL of deionized water and stir for 5min, then dissolve SnCl ₄ with 5ml of deionized water, and then dissolve the SnCl4 solution Add an aqueous solution containing ZnO, NaOH, and CTAB dropwise, stir well for 10 minutes and let it stand for 24 hours, then stir the solution for 5 minutes, then transfer it to a hydrothermal reaction kettle, and conduct a hydrothermal reaction at 200°C for 12 hours. After the reaction was completed, each was washed three times with deionized water and absolute ethanol, and then the precipitate was dried at 60°C in an air atmosphere, and the hierarchical hollow cubic tin dioxide nanoparticles composed of nanosheets and nanorods were collected. See attached drawing 5 for the scanned picture, and attached attached drawing 6 for the transmission scanned picture.

Claims (7)

1. a preparation method of graded hollow cube-shaped tin dioxide nanoparticles, is characterized in that, comprises the following concrete steps: The first step is to prepare a solution containing solid cubic-shaped zinc hydroxystannate nanoparticles, and use the co-precipitation method to mix and stir the aqueous solution containing zinc source, tin source, alkali and surface protection agent at room temperature; The second step is to move the above solution into the hydrothermal reaction kettle, put it into a constant temperature blast oven, and set the constant temperature of the oven; In the third step, after a period of hydrothermal reaction, hierarchical hollow cubic tin dioxide nanoparticles composed of ultrafine nanorods are directly generated. 2. the preparation method of a kind of hierarchical hollow cubic tin dioxide nanoparticles according to claim 1, is characterized in that: In the first step, the step of preparing a solution containing solid cubic zinc hydroxystannate nanoparticles is: at room temperature, first configure an aqueous solution containing ZnO, NaOH, and CTAB, the concentrations of which are respectively 0.003-0.01 mol/liter of ZnO; ; 0.02-0.04 moles/liter of CTAB; 0.2-0.4 moles/liter of NaOH; Then configure an aqueous solution containing SnCl4, the concentration of which is 0.1-0.3 mol/liter, add the SnCl4 solution dropwise to the above aqueous solution containing ZnO, NaOH, and CTAB, stir well and let it stand for a while. 3. the preparation method of a kind of hierarchical hollow cubic shape tin dioxide nanoparticles according to claim 1, is characterized in that: In the second and third steps, fully stir the mixed solution obtained in the first step, and then move it into a 50ml hydrothermal reaction kettle, and conduct a hydrothermal reaction at 160-210°C for 8-15h; Centrifugal cleaning with water and ethanol for 3 times, centrifugation at 6500 rpm for 3-5 minutes, and finally drying at 60°C to obtain hierarchical hollow cube-shaped tin dioxide nanoparticles composed of ultrafine nanorods. 4. the preparation method of a kind of hierarchical hollow cubic tin dioxide nanoparticles according to claim 2, is characterized in that: The configuration contains an aqueous solution of SnCl4: dissolve ZnO, NaOH, and CTAB with deionized water, and stir thoroughly. 5. the preparation method of a kind of hierarchical hollow cubic shape tin dioxide nanoparticles according to claim 2, is characterized in that: Dissolve SnCl ₄ in deionized water, then add the SnCl 4 solution dropwise to the aqueous solution containing ZnO, NaOH, and CTAB, stir well and let stand for a period of time. 6. the preparation method of a kind of hierarchical hollow cubic tin dioxide nanoparticles according to claim 4, is characterized in that: The time for the full stirring is 5 min. 7. the preparation method of a kind of hierarchical hollow cube-shaped tin dioxide nanoparticles according to claim 5, is characterized in that: After the full stirring for 10 min, let stand for 24 h.