阅读说明：本技术 一种硫化铅溶胶的制备方法 (Preparation method of lead sulfide sol ) 是由 邓宏 姜文来 冯强 李星宇 肖明迪 何思祺 于 2020-12-25 设计创作，主要内容包括：本发明提供一种硫化铅溶胶的制备方法,属于电子材料技术领域。本发明中制备方法通过选择恰当的络合剂和溶剂、严格设计前驱体溶液配制流程,通过后续的时化处理,获得具有明显丁达尔效应的稳定溶胶。且本发明中合成制备的硫化铅溶胶具有良好的均匀性和稳定性。(The invention provides a preparation method of lead sulfide sol, belonging to the technical field of electronic materials. The preparation method of the invention obtains the stable sol with obvious Tyndall effect by selecting proper complexing agent and solvent, strictly designing the preparation flow of the precursor solution and carrying out subsequent time processing. The lead sulfide sol synthesized and prepared in the invention has good uniformity and stability.)

1. A preparation method of lead sulfide sol is characterized by comprising the following steps:

step 1, dissolving a complexing agent into ethylene glycol, and uniformly stirring and mixing to obtain a solution A, wherein the volume ratio of the complexing agent to the ethylene glycol is 1: (8-15);

step 2, adding a lead source into the solution A prepared in the step 1, and stirring to obtain a solution B;

step 3, adding a sulfur source into an ethylene glycol solvent, and uniformly stirring and mixing to obtain a solution C, wherein the concentration of the sulfur source in the solution C is 0.1-1 mol/L;

step 4, adding the glycol solvent into the solution B prepared in the step 2 again to disperse the solution B again, uniformly stirring, standing for 20-40 min, and taking supernatant after standing;

and 5, dropwise adding the solution C obtained in the step 3 into the supernatant obtained in the step 4, and stirring the solution while dropwise adding to obtain a mixed solution D, wherein the molar ratio of lead ions to sulfur ions in the mixed solution D is (4-1): 1;

step 6, standing the mixed solution D obtained in the step 5 to settle large suspended particles;

and 7, carrying out time-based treatment on the solution after standing in the step 6 to prepare the required lead sulfide sol.

2. The method for preparing a lead sulfide sol according to claim 1, wherein the complexing agent in step 1 is ethylenediamine tetraacetic acid, triethylamine, butylamine, or ethylenediamine.

3. The method for producing a lead sulfide sol according to claim 1, wherein the lead source in step 2 is lead nitrate, lead chloride, lead iodide or lead acetate trihydrate.

4. The method for producing a lead sulfide sol according to claim 1, wherein the sulfur source in step 3 is sodium sulfide nonahydrate or thiourea.

5. The method for preparing a lead sulfide sol according to claim 1, wherein the stirring time in the step 2 is 5 to 15 min; and 3, stirring for 5-10 min.

6. The method for preparing lead sulfide sol according to claim 1, wherein the stirring in step 5 is performed by a magnetic stirrer for 5-15 min.

7. The method for preparing a lead sulfide sol according to claim 1, wherein the standing time in the step 6 is 3 to 5 hours.

8. The method for preparing lead sulfide sol according to claim 1, wherein the specific process of the aging treatment in step 7 is: treating for 2-5 h at 80-120 ℃.

9. A method for preparing lead sulfide thin films is characterized in that lead sulfide sol obtained by the method of any one of claims 1 to 8 is uniformly coated on a cleaned substrate by a pulling or spin coating method, then heat treatment is carried out, and the steps of spin coating and heat treatment are repeated, so that the required lead sulfide thin films can be obtained on various substrates.

10. A preparation method of lead sulfide nano powder is characterized in that a coating agent is added into lead sulfide sol obtained by the method of any one of claims 1 to 8 to gelatinize the lead sulfide sol, and then drying treatment is carried out to obtain the required lead sulfide nano powder.

Technical Field

The invention belongs to the technical field of electronic material preparation, relates to preparation of a narrow bandgap semiconductor material, and particularly relates to a preparation method of lead sulfide sol.

Background

As an important IV-VI semiconductor compound, the lead sulfide has a small energy band gap (0.41eV), a relatively large exciton Bohr radius (18nm) and a nonlinear optical coefficient, and is widely applied to the fields of infrared detectors, solar cells and the like. For the field of photodetection: although various novel semiconductor detectors are in the future, the lead sulfide detector is still a core component of an infrared system with a wave band of 1-3 μm due to the advantages of simple preparation process, high response rate, no need of low-temperature cooling treatment, low cost and the like, and is still widely applied to the fields of infrared temperature measurement, infrared guidance, infrared early warning, infrared astronomical observation and the like. Practical lead sulfide detectors are generally of thin-film structures, and the current preparation method mainly comprises three steps: chemical liquid phase processes, electrodeposition processes, and electrochemical processes. For the field of solar cells: the power conversion efficiency of the currently-certified lead sulfide quantum dot solar cell is over 10 percent, and the method shows a huge commercial prospect, wherein the preparation of the lead sulfide nano-particles is a very important ring and directly concerns the performance of devices.

The sol is an important means for preparing nano materials and films, and has a series of advantages of simple preparation process, low reaction temperature, easy film formation, high product purity and the like. The general procedure for preparing sols is to dissolve metal alkoxides or minerals in a reagent such as deionized water or ethanol to form a clear solution, which is formed into a sol based on hydrolysis and polycondensation reactions. Then uniformly coating the sol on a substrate material by using a spin coating method, and preparing a film sample by heat treatment; or heat treating the colloid to obtain nanometer powder. Because the sol synthesis mechanism is based on hydrolysis and polycondensation reaction, the oxide semiconductor material is generally prepared, so that no method for preparing pure lead sulfide sol is reported at home and abroad at present. The existing process for preparing lead sulfide sol is to forcibly disperse lead sulfide in a glass sol matrix synthesized in advance, lead sulfide is only used as doping, and most of the prepared materials are compounds, so that the preparation of pure lead sulfide sol has very important significance.

Disclosure of Invention

Aiming at the problem that the prior art has no preparation method of pure lead sulfide sol in the background art, the invention aims to provide a preparation method of lead sulfide sol. The method selects a material having a coordination function with lead ions as a complexing agent, and uses a lead source and a sulfur source to react to synthesize the lead sulfide sol in the presence of ethylene glycol, wherein the colloid has good stability at room temperature.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of lead sulfide sol comprises the following steps:

step 1, dissolving a complexing agent into ethylene glycol, and uniformly stirring and mixing to obtain a solution A, wherein the volume ratio of the complexing agent to the ethylene glycol is 1: (8-15);

step 2, adding a lead source into the solution A prepared in the step 1, and stirring to obtain a solution B;

step 3, adding a sulfur source into an ethylene glycol solvent, and uniformly stirring and mixing to obtain a solution C, wherein the concentration of the sulfur source in the solution C is 0.1-1 mol/L;

step 4, adding the glycol solvent into the solution B prepared in the step 2 again to disperse the solution B again, uniformly stirring, standing for 20-40 min, and taking supernatant after standing;

and 5, dropwise adding the solution C obtained in the step 3 into the supernatant obtained in the step 4, and stirring the solution while dropwise adding to obtain a mixed solution D, wherein the molar ratio of lead ions to sulfur ions in the mixed solution D is (4-1): 1;

step 6, standing the mixed solution D obtained in the step 5 to enable large suspended particles to settle and obtain a stable solution with uniform particle size distribution;

and 7, carrying out time-based treatment on the solution after standing in the step 6 to prepare the required lead sulfide sol.

Further, the complexing agent in step 1 is a material having a coordination effect with lead ions, and preferably, ethylenediaminetetraacetic acid, triethylamine, butylamine, ethylenediamine, and the like.

Further, the lead source in step 2 is preferably lead nitrate, lead chloride, lead iodide, lead acetate trihydrate, or the like.

Further, the sulfur source in step 3 may be sodium sulfide nonahydrate or thiourea.

Further, the stirring time in the step 2 is 5-15 min; and 3, stirring for 5-10 min.

Further, in the step 5, a magnetic stirrer is adopted for stirring, and the stirring time is 5-15 min.

Further, the standing time in the step 6 is 3-5 hours.

Further, the specific process of the temporal processing in step 7 is as follows: treating for 2-5 h at 80-120 ℃.

A preparation method of a lead sulfide film comprises the steps of uniformly coating lead sulfide sol obtained by the method on a cleaned substrate by utilizing a drawing or spin coating method, then carrying out heat treatment, and repeating the steps of spin coating and heat treatment to obtain the required lead sulfide film on various substrates.

A process for preparing nano lead sulfide powder includes such steps as adding a proper amount of coating agent to the lead sulfide sol, gelatinizing, and baking.

The mechanism of the invention is as follows: in the preparation method, the lead source and the complexing agent are mixed and react to form a metal complex Pb [ (TEA)]²⁺Thereby preventing direct precipitation after the subsequent lead sulfide generation and controlling Pb²⁺And S^2-The interaction of (a) and (b) makes the reaction proceed smoothly; meanwhile, the invention adopts ethylene glycol as a solvent, which has certain viscosity, so that lead sulfide particles generated by the reaction can be better dispersed in the solvent; finally, the lead sulfide particles stably exist in the glycol solution after a certain time of aging treatment, and the lead sulfide particles still have good stability even if being stored for several days.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the lead sulfide sol prepared by the invention has obvious Tyndall effect, has good stability at room temperature, and can not generate obvious settlement after being placed for a plurality of days.

2. The preparation method has the advantages of simple process, easy control and low material cost, and is suitable for industrial large-scale production.

3. The preparation method fills the blank of the field of preparation of the lead sulfide sol, successfully expands the preparation process of the lead sulfide film, and the prepared product can be widely applied to the fields of infrared detector windows, solar cell photosensitive layers and the like.

Drawings

FIG. 1 is a diagram of a lead sulfide sol prepared in example 1 of the present invention.

FIG. 2 is an SEM photograph of lead sulfide particles prepared in example 1 of the present invention.

FIG. 3 is a diagram of a lead sulfide sol prepared in example 2 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings.

A preparation method of lead sulfide sol comprises the following steps:

step 1, dissolving a complexing agent into ethylene glycol, and uniformly stirring and mixing to obtain a solution A, wherein the volume ratio of the complexing agent to the ethylene glycol is 1: (8-15); the ethylene glycol has certain viscosity, and can achieve a good dispersing effect on the synthesized lead sulfide particles;

step 2, adding a lead source into the solution A prepared in the step 1, and stirring to obtain a solution B;

step 3, adding a sulfur source into an ethylene glycol solvent, and uniformly stirring and mixing to obtain a solution C, wherein the concentration of the sulfur source in the solution C is 0.1-1 mol/L;

step 4, adding the glycol solvent into the solution B prepared in the step 2 again to disperse the solution B again, uniformly stirring, standing for 20-40 min, and taking supernatant after standing;

and 5, dropwise adding the solution C obtained in the step 3 into the supernatant obtained in the step 4, and stirring the solution while dropwise adding to obtain a mixed solution D, wherein the molar ratio of lead ions to sulfur ions in the mixed solution D is (4-1): 1; wherein, the lead source is excessive, so that the reaction is easier to be carried out towards the direction of generating products, and the reaction is carried out more fully;

step 6, standing the mixed solution D obtained in the step 5 to enable large suspended particles to settle and obtain a stable solution with uniform particle size distribution; the standing is to obtain a stable solution with uniformly dispersed lead sulfide particles, and if the mixed solution D is directly taken without standing for time chemical treatment, all the lead sulfide particles in the solution are precipitated, so that the target sol cannot be obtained;

and 7, carrying out time-based treatment on the solution after standing in the step 6 to prepare the required lead sulfide sol.

Example 1

A preparation method of lead sulfide sol comprises the following steps:

step 1, dissolving 4ml of analytically pure triethylamine complexing agent (AR 99%) in ethylene glycol, and uniformly stirring and mixing to obtain a solution A, wherein the volume ratio of the complexing agent to the ethylene glycol is 1: 10;

step 2, adding 0.4mmol of analytically pure lead nitrate into the solution A prepared in the step 1, and stirring for 10min to obtain a solution B;

step 3, adding analytically pure sodium sulfide nonahydrate into an ethylene glycol solvent, and uniformly stirring and mixing to obtain a solution C, wherein the concentration of the sodium sulfide nonahydrate in the solution C is 0.1 mol/L;

step 4, adding 20ml of glycol solvent into the solution B prepared in the step 2 again to disperse the solution B again, stirring uniformly, standing for 30min, and taking supernatant after standing;

and 5, dropwise adding the solution C obtained in the step 3 into the supernatant obtained in the step 4, wherein the color of the solution is changed from white to dark brown and finally to black, the whole process is very quick, and stirring the solution by using a magnetic stirrer while dropwise adding is carried out for 10min to obtain a mixed solution D, wherein the molar ratio of lead nitrate to sodium sulfide in the mixed solution D is 2: 1;

step 6, standing the mixed solution D obtained in the step 5 for 3 hours to settle large suspended particles and obtain a stable solution with uniform particle size distribution;

and 7, putting the solution subjected to standing treatment in the step 6 into a preheated infrared lamp oven with the temperature of 100 ℃ for time-based treatment for 4 hours to prepare the required lead sulfide sol.

Fig. 1 shows a physical diagram of the lead sulfide sol prepared in this example, and fig. 2 shows an SEM diagram of the lead sulfide particles in the sol.

As can be seen from fig. 1, the product prepared in this example has a pronounced tyndall effect, indicating that the lead sulfide sol was successfully prepared. As can be seen from fig. 2, the colloidal particles in the lead sulfide sol prepared in this embodiment are distributed uniformly, and the particle size is in the nanometer level.

Example 2

The lead sulfide sol was prepared according to the procedure of example 1, and the time-based treatment time in step 7 was adjusted to 1.5 hours, and the other steps were not changed, to prepare the desired lead sulfide sol.

Fig. 3 shows a schematic diagram of the lead sulfide sol prepared in this example.

As can be seen from fig. 3, the lead sulfide sol prepared in this example also has a significant tyndall effect. Compared with the example 1, the time-lapse treatment time of the example is shorter, the color of the prepared sol is darker, which shows that the concentration of lead sulfide in the sol is higher; and the sol prepared by the embodiment is settled after being placed for 2-3 days at room temperature, and the stability is slightly poor.

Example 3

A lead sulfide sol was prepared according to the procedure of example 1, and only the volume ratio of the complexing agent to ethylene glycol in step 1 was adjusted to 1: and 8, preparing the required lead sulfide sol without changing other steps.

This example enables the successful preparation of lead sulfide sols.

Comparative example 1

The lead sulfide sol was prepared according to the procedure of example 1, and the desired lead sulfide sol was prepared by adjusting the volume ratio of the complexing agent to ethylene glycol in step 1 to 1:5 only, without changing the other steps.

This comparative example failed to successfully prepare a lead sulfide sol because the amount of ethylene glycol by volume was too small.

Comparative example 2

The lead sulfide sol was prepared according to the procedure of example 1, and the desired lead sulfide sol was prepared by adjusting the standing time in step 6 to 1 hour only, without changing the other steps.

This comparative example failed to successfully prepare a lead sulfide sol due to too short a standing time.

While the invention has been described with reference to specific embodiments, any feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise; all of the disclosed features, or all of the method or process steps, may be combined in any combination, except mutually exclusive features and/or steps.