Solvothermal method for synchronously preparing SnS2 and SnO2 and application

Abstract

The invention provides a solvothermal method for synchronously preparing SnS2 and SnO2 and application, and belongs to the technical field of material synthesis. According to the method, stannic chloride and thiourea are used as raw materials, one-step preparation of the pure-phase SnS2 nano material and the pure-phase SnO2 nano material is achieved through a solvothermal method and accurate regulation and control of reaction conditions, the prepared material is high in phase purity and free of impurity phases, a complex separation or post-treatment process is not needed, the obvious advantage of process intensification is achieved, and the method is suitable for industrial production. The method has important significance in promoting large-scale application of SnS2 and SnO2 in the engineering practical fields of photocatalysis, semiconductor devices, machinery, aviation and the like; the pure-phase SnS2 nano material and the pure-phase SnO2 nano material prepared by the method can be independently used, and both the pure-phase SnS2 nano material and the pure-phase SnO2 nano material show a good effect of efficiently photodecomposing the rhodamine B dye by applying the pure-phase SnS2 nano material and the pure-phase SnO2 nano material to photocatalytic degradation of the rhodamine B dye respectively.

Description

TECHNICAL FIELD

[0001] The application relates to a solvothermal method for synchronously preparing SnS2 and SnO2 and application thereof, and belongs to the technical field of material synthesis. BACKGROUND

[0002] Both tin disulfide (SnS2) and tin dioxide (SnO2) are typical semiconductor materials, and are widely used in the fields of semiconductor devices, machinery, aviation and the like. Pure-phase SnS2 has a hexagonal CdI2 type "sandwich" layered structure, a relatively narrow band gap (about 2.2 ev), strong ultraviolet light response, adjustable specific surface area and morphology, and rich sources; pure-phase SnO2 is a typical n-type semiconductor material, has a band gap of 3.6 eV, good chemical stability and photocatalytic activity, is cheap and easy to obtain, and is non-toxic and harmless; both of them have irreplaceable application value in scenes such as photocatalytic degradation of organic pollutants, hydrogen production by water photolysis, CO2 photoreduction and the like. Therefore, obtaining high-purity pure-phase SnS2 and SnO2 materials is the basis for realizing efficient application of the two and flexible design of subsequent photocatalytic systems.

[0003] However, in the prior art, the preparation of SnS2 and SnO2 is still limited to the technical path of "separate synthesis", and there is no effective scheme for synchronously preparing the two pure-phase materials. The hydrothermal method is a common method for synthesizing compounds at present, but for the synthesis of SnS2 and SnO2 nanomaterials, the technical path is to first prepare tin dioxide nanoparticles, and then partially sulfide the tin dioxide nanoparticles in a solution to obtain tin disulfide, which has the disadvantages that the sulfidation degree is difficult to control, and the nanoparticles are easy to agglomerate, so that the final product obtained is usually a SnS2 / SnO2 composite material, and it is difficult to obtain pure-phase SnS2 or SnO2 nanomaterials; therefore, for the synchronous preparation of pure-phase SnS2 or SnO2 nanomaterials by one-step method, there is still a technical blank in the prior art, and the synchronous preparation of the two pure-phase materials is of great significance for simplifying the preparation process of SnS2 and SnO2, reducing the cost and constructing a new photocatalyst. SUMMARY

[0004] In view of the existing problems, the application provides a solvothermal method for synchronously preparing SnS2 and SnO2, which realizes the synchronous preparation of SnS2 and SnO2 by one-step solvothermal method, and the prepared SnS2 and SnO2 are both nanoscale particles with high phase purity and can be used alone.

[0005] The technical scheme of the application is as follows: The application provides a solvothermal method for synchronously preparing SnS2 and SnO2, which is characterized by using tin chloride pentahydrate as a tin source and thiourea as a sulfur source to perform a solvothermal reaction in a hydrothermal kettle.

[0006] Furthermore, the solvothermal reaction includes the following steps: S1. Dissolve the tin source thoroughly in ethanol to obtain a tin source solution; S2. Dissolve the sulfur source thoroughly in ethanol to obtain a sulfur source solution; S3. According to the molar ratio of tin source to sulfur source of 1:2.6, the tin source solution is added dropwise to the sulfur source solution or the sulfur source solution is added dropwise to the tin source solution while stirring and mixing. The order of addition does not affect the results and similar materials can be obtained. Then, the mixed solution is sealed in a hydrothermal reactor and reacted at 140°C. S4. After the reaction, the reaction solution is removed, filtered, washed and dried to obtain white nanoparticles, namely SnO2. S5. Scrape off the yellow nanoparticles adhering to the wall of the hydrothermal reactor, wash and dry them to obtain SnS2, thus achieving the simultaneous preparation of SnS2 and SnO2.

[0007] Furthermore, the tin source concentration in the tin source solution described in step S1 is 0.1 mol / L.

[0008] Furthermore, the sulfur source concentration in the sulfur source solution in step S2 is 0.26 mol / L.

[0009] Furthermore, the reaction time in step S3 is 6 hours.

[0010] The solvothermal method for simultaneous preparation of SnS2 and SnO2 provided by the present invention can be applied to the photocatalytic degradation of organic dye pollutants.

[0011] This invention also provides a method for photocatalytic degradation of organic dye pollutants, comprising the following specific steps: SnS2 and SnO2 nanoparticles were prepared using the solvothermal method described above for the simultaneous preparation of SnS2 and SnO2. The obtained SnS2 nanoparticles or SnO2 nanoparticles were added to an organic dye pollutant solution and dispersed evenly. Then, the organic dye pollutants were photocatalytically degraded under ultraviolet light mercury lamp irradiation.

[0012] Furthermore, the organic dye pollutant is Rhodamine B.

[0013] Unlike existing technologies, this invention has the following advantages: 1. This invention uses tin chloride and thiourea as raw materials. By utilizing a solvothermal method and precise control of reaction conditions, a hydrothermal reaction is carried out in an ethanol solvent. After the reaction, the white reaction liquid remaining in the reactor contains SnO2 nanoparticles suspended in it, while the yellow solid adhering to the reactor wall is SnS2 nanoparticles. The resulting materials are all pure phase structures with no impurities. Furthermore, no complex separation or post-processing is required, exhibiting significant advantages in process integration. The process is simple, and the reaction conditions are highly controllable, effectively promoting the large-scale application of SnS2 and SnO2 in practical engineering fields such as photocatalysis, semiconductor devices, machinery, and aerospace.

[0014] 2. The SnO2 nanoparticles and SnS2 nanoparticles prepared by this invention have high phase purity and can be used as individual pure phase materials. When the prepared SnO2 nanoparticles and SnS2 nanoparticles are added to organic dye pollutant solutions, both exhibit efficient photodecomposition of organic dye pollutants. This effect also provides more possibilities for the flexible design of SnO2 and SnS2 photocatalytic systems (single use or composite design), which helps to promote the practical application of photocatalytic technology in environmental protection, energy and other fields. Attached Figure Description

[0015] Figure 1 XRD patterns of SnS2 and SnO2 prepared in Example 1.

[0016] Figure 2 The degradation rates of Rhodamine B by SnS2 and SnO2 nanoparticles are given. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0018] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Unless otherwise specified, the methods described in the following embodiments are conventional methods.

[0019] Example 1 This embodiment provides a solvothermal method for the simultaneous preparation of SnS2 and SnO2, including the following specific steps: S1. Using tin chloride pentahydrate (SnCl4·5H2O) as the tin source, weigh 0.01 mol of SnCl4·5H2O and dissolve it in 100 mL of ethanol to obtain the tin source solution; S2. Using thiourea (CH4N2S) as the sulfur source, weigh 0.026 mol of CH4N2S and dissolve it in 100 mL of ethanol to obtain a sulfur source solution. S3. Add the tin source solution dropwise to the sulfur source solution while stirring and mix thoroughly to obtain a mixed solution; S4. The mixture obtained in step S3 is evenly distributed into eight 30 mL hydrothermal reactors, each containing about 24 mL of liquid. All reactors are hydrothermally heated at 140°C for 6 hours. S5. After the reaction, the reaction solution is removed, filtered, washed and dried to obtain white nanoparticles, namely SnO2. S6. Scrape off the yellow nanoparticles adhering to the wall of the hydrothermal reactor, wash and dry them to obtain SnS2, thereby achieving the simultaneous preparation of SnS2 and SnO2.

[0020] Example 2 This embodiment provides a solvothermal method for the simultaneous preparation of SnS2 and SnO2, which differs from Embodiment 1 in that: in step S3, the sulfur source solution is added dropwise to the tin source solution under stirring and mixed thoroughly to obtain a mixed solution; the remaining steps are the same as in Embodiment 1, and will not be repeated here.

[0021] In this embodiment, white nanoparticles SnO2 and yellow nanoparticles SnS2 were also prepared.

[0022] Performance testing In this invention, SnO2 nanoparticles and SnS2 nanoparticles prepared by the solvothermal method of simultaneous preparation of SnS2 and SnO2 as described in Example 1 were subjected to XRD tests to test the purity of the prepared SnS2 and SnO2 phases. They were then applied to the photocatalytic degradation of organic dye pollutants to evaluate the application potential of SnS2 and SnO2 prepared by the solvothermal method.

[0023] Figure 1 The XRD patterns of SnO2 nanoparticles and SnS2 nanoparticles obtained in Example 1 are shown. The results show that the diffraction peaks of the two are consistent with the standard card of SnO2 (PDF#41-1445) and the standard card of SnS2 (PDF#23-0677), respectively, and no other impurity phase diffraction peaks appear. This confirms that the obtained SnO2 nanoparticles and SnS2 nanoparticles are both pure phase structures.

[0024] This invention uses Rhodamine B as an organic dye pollutant and SnO2 nanoparticles and SnS2 nanoparticles obtained in Example 1 as catalysts to carry out photocatalytic degradation of the organic dye pollutant. The experiment was conducted according to the following steps: Take 80 mg of SnO2 nanoparticles or 80 mg of SnS2 nanoparticles and add them to 80 mL of 10 -5The SnO2 and SnS2 nanoparticles were uniformly dispersed in a mol / L Rhodamine B solution and subjected to photocatalytic degradation under ultraviolet light mercury lamp irradiation. Then, 4 mL of the suspension was taken every 1 hour and placed in a centrifuge tube. The clear centrifuged liquid obtained was separated by centrifugation. The ultraviolet-visible absorption spectrum of the centrifuged liquid was measured by ultraviolet-visible spectrophotometer to evaluate the photocatalytic degradation effect of SnO2 nanoparticles and SnS2 nanoparticles.

[0025] Figure 2 The degradation rate of Rhodamine B was measured by a UV-Vis spectrophotometer. The results showed that both SnO2 nanoparticles and SnS2 nanoparticles prepared in this invention can be used alone. When the reaction time reached 4 h, the degradation rates of Rhodamine B by SnS2 and SnO2 reached 91.97% and 87.96%, respectively. Both SnS2 and SnO2 nanomaterials showed good degradation effects on Rhodamine B.

Claims

1. A solvothermal method for the simultaneous preparation of SnS2 and SnO2, using tin chloride pentahydrate as the tin source and thiourea as the sulfur source, wherein the solvothermal reaction is carried out in a hydrothermal reactor, characterized in that, The solvothermal reaction includes the following steps: S1. Dissolve the tin source thoroughly in ethanol to obtain a tin source solution; S2. Dissolve the sulfur source thoroughly in ethanol to obtain a sulfur source solution; S3. According to the molar ratio of tin source to sulfur source of 1:2.6, add the tin source solution dropwise to the sulfur source solution or add the sulfur source solution dropwise to the tin source solution, while stirring and mixing. Then, seal the mixture in a hydrothermal reactor and react at 140°C. S4. After the reaction, the reaction solution is removed, filtered, washed and dried to obtain white nanoparticles, namely SnO2. S5. Scrape off the yellow nanoparticles adhering to the wall of the hydrothermal reactor, wash and dry them to obtain SnS2, thus achieving the simultaneous preparation of SnS2 and SnO2.

2. The solvothermal method for simultaneous preparation of SnS2 and SnO2 according to claim 1, characterized in that, The concentration of tin source in the tin source solution mentioned in step S1 is 0.1 mol / L.

3. The solvothermal method for simultaneous preparation of SnS2 and SnO2 according to claim 1, characterized in that, The sulfur source concentration in the sulfur source solution in step S2 is 0.26 mol / L.

4. The solvothermal method for simultaneous preparation of SnS2 and SnO2 according to claim 1, characterized in that, The reaction time in step S3 is 6 hours.

5. The solvothermal method for simultaneously preparing SnS2 and SnO2 as described in any one of claims 1 to 4 is applied to the photocatalytic degradation of organic dye pollutants.

6. A method for photocatalytic degradation of organic dye pollutants, characterized in that, The specific steps include the following: SnS2 and SnO2 nanoparticles were prepared using the solvothermal method for simultaneous preparation of SnS2 and SnO2 as described in any one of claims 1 to 4. The obtained SnS2 or SnO2 nanoparticles were added to an organic dye pollutant solution and dispersed evenly. Then, the organic dye pollutants were photocatalytically degraded under ultraviolet light mercury lamp irradiation.

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