PbTe micro-nano nonlinear optical material with hollow structure

Abstract

The invention discloses a PbTe micro-nano nonlinear optical material with a hollow structure. A PbTe micro-nano material with a controllable structure is prepared by utilizing a microwave polyol method. TeO2 and Pb (NO3) 2 are used as main raw materials, under the condition that ethylene glycol is used as a reducing agent and a solvent, a fixed amount (0.3 g) of NaOH is weighed and prepared into a 0.15 g / mL alkali solution, 1 mmol of TeO2 and 1 mmol of Pb (NO3) 2 raw materials are sequentially added and fully stirred, a microwave heating reaction is conducted for 2 h at the temperature of 180 DEG C, the obtained black precipitate is centrifugally washed, impurities are removed, and the TeO2 / Pb composite material with the good crystallinity and the high purity is successfully prepared. And the hollow-structure PbTe micro-nano material is uniform in morphology. The method provided by the invention has the characteristics of simple and easy operation, easily available raw materials, low cost, high efficiency, easy popularization and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of nonlinear optics, and the prepared material can be used for laser protection. Specifically, it relates to a hollow-structured PbTe micro-nano material. Background Art

[0002] Currently, the preparation of optical limiting materials has become one of the hottest research directions in nanoscience and technology. In recent years, hollow micro-nano structures with sizes ranging from 10 nm to 10 μm have been widely studied due to their interesting structures, high surface areas, and low mass densities. These special properties make hollow spheres have potential applications in many aspects such as catalysis, drug delivery, sensors, microreactors, coatings, and solar cells. At the same time, PbTe nano-materials have been extensively studied in various morphological structures. However, there are few reports on the synthesis of PbTe hollow microsphere structures. The research on the nonlinear optical properties of PbTe hollow structures has not been reported yet. Therefore, the preparation of hollow-structured PbTe and the study of its nonlinear optical properties are worthy of exploration.

[0003] Starting from the perspective of nano-material morphology design, the present invention uses the microwave polyol method to prepare micro-nano PbTe powder with uniform morphology, good crystallinity, and stable crystal form. The hollow-structured PbTe micro-nano material prepared by the present invention using the microwave polyol method has easily available raw materials, mild conditions, and simple operations. The successfully prepared PbTe of the present invention has a large specific surface area and good nonlinear optical properties for future applications in the field of laser protection. Summary of the Invention

[0004] The purpose of the present invention is to successfully prepare a hollow-structured PbTe micro-nano optical limiting material assembled and stacked by relatively regular blocks through a simple microwave polyol method. The prepared PbTe is in the micro-nano range and has advantages such as good structural stability. In addition, the synthesized narrow-bandgap PbTe semiconductor material provides the possibility for its application in the field of laser protection. The method of the present invention is simple, easy to operate, has easily available raw materials, low cost, and is easy to promote.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: A preparation method of a hollow-structured PbTe micro-nano optical limiting material, comprising the following steps: (1) Preparation of NaOH solution: Mix an appropriate amount of NaOH and deionized water and stir evenly to obtain a NaOH solution; (2) Dissolve TeO2 in the alkali solution prepared in step (1) and disperse it evenly by ultrasonic treatment; (3) Dissolve Pb(NO3)2 in the solution obtained in step (2) and stir evenly with a magnetic stirrer; (4) Add ethylene glycol to the solution obtained in step (3), and stir magnetically to mix evenly; (5) Add the surfactant to the solution obtained in step (4), and stir magnetically evenly under water bath to obtain a homogeneous and transparent solution; (6) Transfer the solution obtained in step (5) into a reaction kettle, place it on a microwave synthesizer for microwave heating reaction. After the reaction is completed, cool it naturally to room temperature; (7) Wash the precipitate obtained in step (6) clean; (8) Transfer the product obtained in step (7) into a freeze-dryer for drying to obtain a hollow-structured PbTe micro-nano nonlinear optical material.

[0006] Further, in step (1), the dosage of NaOH is 0.3 g, and the mass concentration of the NaOH solution is 0.15 g / mL; Further, in step (2), the dosage of TeO2 is 1 mmol, and ultrasonic dispersion is carried out for 5 min; Further, in step (3), the dosage of Pb(NO3)2 is 1 mmol, and magnetic stirring is carried out for 10 min; Further, in step (4), the dosage of ethylene glycol is 18 mL, and magnetic stirring is carried out for 10 min; Further, in step (5), the surfactant is CTAB, the dosage is 0.3 g, the water bath temperature is 90 °C, and magnetic stirring is carried out for 15 min; Further, in step (6), the model of the microwave synthesizer is Biotage Initiator +, the reaction temperature is 180 °C, and the reaction time is 2 h; Further, the washing method in step (7) is specifically to alternately centrifuge and wash with deionized water and absolute ethanol until the pH of the supernatant is neutral. The centrifugation speed is 11,000 r / min, and the centrifugation time for one time is 5 min.

[0007] Further, in step (8), the freeze-drying temperature is -40 to -50 °C, and the drying time is 24 h.

[0008] The remarkable advantages of the present invention are as follows: Starting from the perspective of material synthesis, the present invention uses the microwave polyol method to prepare a hollow-structured PbTe micro-nano material with relatively uniform morphology and size, good crystallinity, stable crystal form, simple preparation process, low synthesis cost, and wide applications. It can be used in multiple fields such as infrared diodes, quantum dot lasers, optoelectronics, ferroelectrics, and thermoelectric devices.

[0009] Compared with PbTe nano materials with other morphologies, it has the following advantages: (1) Novel morphology: A hollow-structured PbTe micro-nano material constructed by self-assembly of regular blocks, with relatively uniform size; (2) The hollow-structured PbTe micro-nano material of the present invention has good nonlinear optical properties and has broad application prospects in the field of laser protection.

[0010] Drawings of the specification Figure 1 It is the FESEM image of the hollow-structured PbTe micro-nano material; Figure 2 It is the XRD spectrum of the hollow-structured PbTe micro-nano material; Figure 3 It is the FT-IR spectrum of the hollow-structured PbTe micro-nano material; Figure 4 It is the nonlinear optical property diagram of the hollow-structured PbTe micro-nano material; Figure 5 It is the comparison diagram of the nonlinear optical properties of PbTe micro-nano materials with different morphologies. Specific embodiments

[0011] In order to make the content of the present invention easier to understand, the following examples will further illustrate the present invention, but are not intended to limit the scope of the present invention.

[0012] Example 1 A preparation method of a hollow-structured PbTe micro-nano nonlinear optical material, comprising the following steps: (1) Add 0.3 g of NaOH to a 25 mL beaker, add 2 mL of deionized water to dissolve, and stir evenly to obtain a homogeneous and transparent solution; (2) Dissolve 1 mmol (0.1578 g) of TeO2 in the alkaline solution prepared in step (1), and ultrasonically disperse for 5 min; (3) Dissolve 1 mmol (0.333 g) of Pb(NO3)2 in the solution obtained in step (2), and magnetically stir for 10 min; (4) Add 18 mL of ethylene glycol to the solution obtained in step (3), magnetically stir for 10 min, and mix evenly; (5) Add 0.3 g of CTAB to the solution obtained in step (4), and magnetically stir at 90 °C in a water bath for 15 min to obtain a homogeneous and transparent solution; (6) Transfer the solution obtained in step (5) to a reaction kettle, place it on a microwave synthesizer of model Biotage Initiator+ for microwave heating reaction, the reaction temperature is 180 °C, the reaction time is 2 h, and after the reaction is completed, naturally cool to room temperature; (7) The precipitate obtained in step (6) was alternately centrifuged and washed with deionized water and absolute ethanol until the pH of the supernatant was neutral. The centrifugation speed was 11,000 r / min, and the centrifugation time for one time was 5 min. (8) The product obtained in step (7) was transferred into a freeze-dryer, where the temperature was -40 °C and the drying time was 24 h. Finally, a black hollow-structured PbTe micro-nano nonlinear optical material was obtained by drying.

[0013] Performance characterization: Figure 1 It is the FESEM image of the PbTe hollow micro-nano material. It can be seen from the figure that the surface of the hollow-structured PbTe is assembled by block stacking, which is a block-combined hollow microsphere, and its diameter is about 10 μm.

[0014] Figure 2 It is the XRD pattern of the PbTe micro-nano material with a hollow structure. It can be seen from the figure that all the peaks correspond to face-centered cubic PbTe (PDF#77-0246). The long and narrow XRD peaks reveal the characteristics of good crystallinity and large particle size of the hollow-structured PbTe.

[0015] Figure 3 It is the FT-IR spectrum of the PbTe micro-nano material with a hollow structure; it can be observed from the figure that the peaks around 2981 cm -1 , 2835 cm -1 , 2710 cm -1 are caused by the stretching vibration and anti-stretching vibration of -C-H in the -CH2 group existing in PbTe. This confirms that the synthesized substance is the PbTe micro-nano material.

[0016] Figure 4 It is the nonlinear optical performance diagram of the PbTe micro-nano material with a hollow structure. In order to study the influence of different laser energies on the nonlinear optical performance of the PbTe micro-nano material with a hollow structure, the Z-scan test was carried out on the sample at 1 μJ, 2 μJ, 3 μJ, and 4 μJ. The results show that the transmittance of the sample at the laser focus presents a valley shape, and at the same time, with the increase of energy, the transmittance at the focus is lower, showing a typical reverse saturation absorption phenomenon. The results indicate that the PbTe micro-nano material with a hollow structure has application value in the field of nonlinear optics.

[0017] Figure 5 It is the comparison diagram of the nonlinear optical performance of the PbTe micro-nano material. The nonlinear optical performance of the PbTe hollow microspheres, PbTe block-combined microspheres, and PbTe block-combined hollow microspheres was tested at a laser energy of 3 μJ, and the results are as Figure 5As shown. At the focus, the transmittance of the hollow microspheres, the block composite microspheres, and the block composite hollow microspheres decreased by 74%, 72%, and 63%, respectively. The results show that among the three morphologies, the PbTe block composite microspheres have the best nonlinear optical properties.

[0018] The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure, characterized in that: It includes the following steps: (1) Preparation of NaOH solution: Mix NaOH and deionized water and stir evenly to obtain a sodium hydroxide solution; (2) Dissolve TeO2 in the alkali solution prepared in step (1) and ultrasonically disperse it evenly; (3) Dissolve Pb(NO3)2 in the solution obtained in step (2) and stir magnetically evenly; (4) Add ethylene glycol to the solution obtained in step (3), stir magnetically and mix evenly; (5) Add a surfactant to the solution obtained in step (4), stir magnetically evenly under water bath to obtain a homogeneous and transparent solution; (6) Transfer the solution obtained in step (5) into a reaction kettle, place it on a microwave synthesizer for microwave heating reaction, and after the reaction is completed, naturally cool it to room temperature; (7) Wash the precipitate obtained in step (6) clean; (8) Transfer the product obtained in step (7) into a freeze-drying oven for drying to obtain a hollow-structured PbTe micro-nano nonlinear optical material.

2. The preparation method of a novel hollow-structured PbTe micro-nano nonlinear optical material according to claim 1, characterized in that, In step (1), the mass concentration of the NaOH solution is 0.15 g / mL.

3. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure according to claim 1, characterized in that, In step (2), the dosage of TeO2 is 1 mmol and ultrasonic dispersion is carried out for 5 min.

4. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure as described in claim 1, characterized in that, In step (3), the dosage of Pb(NO3)2 is 1 mmol and magnetic stirring is carried out for 10 min.

5. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure as described in claim 1, characterized in that, In step (4), the dosage of ethylene glycol is 18 mL and magnetic stirring is carried out for 10 min.

6. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure according to claim 1, characterized in that, In step (5), the surfactant is CTAB, the dosage is 0.3 g, the water bath temperature is 90 °C, and magnetic stirring is carried out for 15 min.

7. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure according to claim 1, characterized in that, In step (6), the reaction temperature is 180 °C and the reaction time is 2 h.

8. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure according to claim 1, characterized in that, The washing method in step (7) is specifically to alternately centrifuge and wash with deionized water and absolute ethanol until the pH of the supernatant is neutral, the centrifugation speed is 11000 r / min, and the centrifugation time for one time is 5 min.

9. The preparation method of a PbTe micro-nano nonlinear optical material with a hollow structure according to claim 1, characterized in that, In step (8), the freeze-drying temperature is -40~-50 °C and the drying time is 24 h.

10. A hollow-structured PbTe micro-nano nonlinear optical material prepared by the preparation method according to any one of claims 1-9.

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