CN104817111B - A kind of room temperature aqueous phase preparation method of bismuth sulfide nanosphere - Google Patents

Abstract

The room temperature aqueous phase preparation method of disclosure a kind of bismuth sulfide nano ball, surfactant is dissolved in deionized water, it is subsequently adding chelating agen, add five nitric hydrate bismuths, stirring under room temperature, sulphur-containing solution is slowly dropped in bismuth ion solution, after mix homogeneously, room temperature reaction 2h, i.e. obtains bismuth sulfide nano ball；The bismuth sulfide nano material pattern that the method for the invention is prepared is good, size is homogeneous, potential using value is had in fields such as thermoelectricity, electronics and opto-electronic devices, this invention described method equipment is simple, mild condition, energy consumption are low, manufacturing cycle is short, easily realize, and is a kind of Perfected process preparing bismuth sulfide nano material.

Description

A kind of room temperature aqueous phase preparation method of bismuth sulfide nanosphere

technical field

The invention relates to the field of preparation of sulfide nanomaterials, in particular to a method for preparing bismuth sulfide nanospheres in an aqueous phase at room temperature.

Background technique

Bismuth sulfide is an important semiconductor material with potential applications in thermoelectric, electronic and optoelectronic devices and infrared spectroscopy. Its forbidden band width is 1.2~1.7eV, which can be used to make photoelectric conversion materials and is widely used in many fields. Nano-scale bismuth sulfide can not only cause blue-shift of ultraviolet-visible absorption wavelength and fluorescence emission wavelength, but also produce nonlinear optical response, enhance the redox ability of nanoparticles, and also have excellent photoelectric catalytic performance. Linear optical materials, photocatalytic materials, etc. have broad application prospects. In recent years, it has also been found that nano-bismuth sulfide is an excellent contrast agent for X-ray tomography (CT), which has unique advantages over traditional iodine contrast agents. For example, bismuth has a strong absorption of X-rays, and more importantly, bismuth sulfide has low toxicity and has little impact on organisms.

The traditional main method for synthesizing bismuth sulfide nanomaterials is the solvothermal method, which needs to be reacted in a closed autoclave, and the obtained particles are not uniform in size and easy to agglomerate. Subsequently, a "hot injection" method appeared to obtain bismuth sulfide particles with uniform particle size distribution, that is, using oleylamine as a ligand and solvent. However, in this process, bismuth ions will inevitably be reduced by oleamide to metal bismuth, which has strong chemical activity and is not suitable for in vivo applications. In addition, during the washing process at the later stage of the experiment, oleylamine was easily detached from the surface of bismuth sulfide nanoparticles due to the weak interaction force, which caused the nanoparticles to easily agglomerate. Later, it was further improved to use oleic acid instead of oleylamine to synthesize bismuth sulfide nanoparticles. Although bismuth sulfide nanoparticles with uniform size can be finally obtained, the reaction system is still an organic phase and requires high temperature heating. In addition, Zhang Qi et al. (Journal of Inorganic Chemistry, 2008, 24, 547-552.) synthesized bismuth sulfide nanoparticles in aqueous medium, but the reaction still required high temperature heating, and the obtained product was not fixed in shape and easily Agglomeration into large pieces is not conducive to later application.

The present invention increases its water solubility by adding a surfactant, avoids the hydrolysis of bismuth by adding a chelating agent, and directly reacts bismuth nitrate with a sulfur source in an aqueous solution to prepare bismuth sulfide nanospheres at room temperature, and microwave, ultrasonic and other methods can also be used. Synthesis, the obtained bismuth sulfide nanospheres have small particle size and good dispersibility.

Contents of the invention

The present invention mainly proposes a room temperature aqueous phase preparation method of bismuth sulfide nanospheres. The obtained bismuth sulfide nanospheres are uniform in size, and the preparation process is simple, the number of equipment is small, the preparation cycle is short, the energy consumption is low, the environment is friendly, and it is easy to popularize. It solves the technical problems in the prior art that high-temperature heating is required, and the shape of the obtained product is not fixed, and it is easy to agglomerate into large pieces, which is not conducive to later application.

The present invention adopts the following technical solutions: a method for preparing bismuth sulfide nanospheres in an aqueous phase at room temperature, comprising the following steps:

Step 1: Dissolve 20 ~ 100 mmol/L chelating agent into 1 ~ 30 mg/mL aqueous solution containing surfactant, then add bismuth nitrate pentahydrate, stir and dissolve at room temperature;

The second step: add 50 ~ 1800 mmol/L sulfur-containing reagent solution dropwise to the mixed solution of the first step, and stir evenly at room temperature;

The third step: the product of the second step is subjected to temperature control in a water bath, ultrasonic reaction or microwave reaction for 10 min to 24 h, and then centrifuged and dried to obtain bismuth sulfide nanospheres.

As a preferred technical solution of the present invention: the chelating agent refers to mannitol or nitrilotriacetic acid.

As a preferred technical solution of the present invention: the concentration of bismuth nitrate in the bismuth nitrate pentahydrate is 20-100 mmol/L.

As a preferred technical solution of the present invention: the surfactant refers to one of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol or polyethylene oxide-polypropylene oxide-polyethylene oxide or multiple mixtures.

As a preferred technical solution of the present invention: the sulfur-containing reagent refers to sodium sulfide, thioacetamide or sodium thiosulfate, the concentration of the sulfur-containing reagent is 50 ~ 1800 mmol/L, at room temperature 25 ° C Stir for 5 min.

As a preferred technical solution of the present invention: the centrifugation treatment is performed at a speed of 8000-10000 rpm for 10 minutes, and the drying treatment refers to vacuum drying at 30°C for 12 hours.

Beneficial effects : the room temperature aqueous phase preparation method of bismuth sulfide nanospheres of the present invention adopts the above technical scheme and compared with the prior art, has the following technical effects: 1. Directly synthesize bismuth sulfide nanomaterials in aqueous phase at room temperature. The obtained bismuth sulfide nanomaterials are solid pellets with a particle size of 200-300nm, good shape and uniform size; 2. The product is not easy to agglomerate and has good dispersibility in water. The reaction can be carried out at normal temperature and pressure, the preparation equipment is simple, the conditions are mild, and the energy consumption is low; 3. The preparation cycle is short, easy to realize and easy to popularize.

Description of drawings:

Figure 1 is a scanning electron microscope (SEM) and a transmission electron microscope (TEM) of bismuth sulfide nanospheres obtained in Example 1 of the present invention;

Fig. 2 is the X-ray diffraction spectrum of the bismuth sulfide nanosphere obtained in Example 1 of the present invention;

Fig. 3 is the SEM scanning electron micrograph of the bismuth sulfide nanosphere obtained in Example 3 of the present invention;

Fig. 4 is the SEM scanning electron micrograph of the bismuth sulfide nanosphere obtained in Example 5 of the present invention;

Fig. 5 is the SEM scanning electron micrograph of the bismuth sulfide nanosphere obtained in Example 6 of the present invention;

Fig. 6 is the SEM scanning electron micrograph of the bismuth sulfide nanosphere obtained in Example 8 of the present invention;

Fig. 7 is the SEM scanning electron micrograph of the bismuth sulfide nanosphere obtained in Example 9 of the present invention;

FIG. 8 is a TEM transmission electron microscope image of the bismuth sulfide nanomaterial obtained in Comparative Example 2 of the present invention.

detailed description

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail:

Example 1:

The first step: to 45mL (20 mg/mL) Add 4.5 mmol of mannitol to polyvinyl alcohol (PVA) aqueous solution, stir and dissolve at room temperature, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min, forming a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a water bath at 25°C for 2 h, then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, Fabricated bismuth sulfide nanospheres.

Example 2:

Step 1: Add 0.5 mmol of bismuth nitrate pentahydrate particles to 45 mL (20 mg/mL) polyvinyl alcohol aqueous solution, stir and dissolve at room temperature for 10 min;

The second step: slowly drop 10 mL (75 mmol/L) thioacetamide solution into the above solution, and stir at room temperature for 5 min to form a bismuth-sulfur mixture.

The experimental results show that in the absence of a chelating agent, bismuth ions are easily hydrolyzed to form white insoluble precipitates, which cannot be followed by subsequent reactions.

Example 3:

The first step: to 45mL (20 mg/mL) Add 2 mmol of nitrilotriacetic acid to the aqueous solution of polyvinyl alcohol, adjust the pH of the solution with sodium hydroxide solution until the solution is clear and transparent, after it is completely dissolved, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min , forming a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a 25°C water bath for 8 h, and then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, made bismuth sulfide nanomaterials.

Example 4:

Step 1: Add 4.5 mmol of mannitol to 45 mL of deionized water, stir and dissolve at room temperature, then add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve for 10 min at room temperature to form a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a water bath at 25°C for 2 h, then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, Fabricated bismuth sulfide nanospheres.

Example 5:

The first step: to 45mL (20 mg/mL) Add 4.5 mmol of mannitol to polyvinylpyrrolidone (PVP) aqueous solution, stir and dissolve at room temperature, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min, and form a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a water bath at 25°C for 2 h, then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, Fabricated bismuth sulfide nanospheres.

Embodiment 6:

Step 1: Add 4.5 mmol of mannitol to 45 mL (20 mg/mL) polyethylene oxide-polypropylene oxide-polyethylene oxide (P ₁₂₃ ) aqueous solution, stir and dissolve at room temperature, then add 0.5 mmol The bismuth nitrate pentahydrate particles were stirred and dissolved at room temperature for 10 min to form a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a water bath at 25°C for 2 h, then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, Fabricated bismuth sulfide nanospheres.

Embodiment 7:

The first step: add 4.5 mmol of mannitol to 45 mL (20 mg/mL) polyethylene glycol aqueous solution,

After stirring and dissolving at room temperature, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min to form a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

The third step: heat the bismuth-sulfur mixture in a water bath at 25°C for 2 h, then perform centrifugation, wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and dry it in vacuum at 20°C for 12 h, made bismuth sulfide nanomaterials.

The experimental results show that when polyethylene glycol is used instead of polyvinyl alcohol, large pieces of flocculent precipitates of bismuth sulfide are formed, and the synthesis effect is not ideal.

Embodiment 8:

Step 1: Add 4.5 mmol of mannitol to 45 mL (20 mg/mL) polyvinyl alcohol aqueous solution, stir and dissolve at room temperature, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min, and form a A solution of bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

Step 3: Put the bismuth-sulfur mixture into a microwave synthesizer and react at 40°C for 40 minutes, then perform centrifugation, and wash the black solid obtained by centrifugation with deionized water and ethanol three times in turn, and vacuum at 20°C. After drying for 12 h, bismuth sulfide nanospheres were made.

Embodiment 9:

The first step: to 45mL (20 mg/mL) Add 4.5 mmol of mannitol to polyvinyl alcohol aqueous solution, stir and dissolve at room temperature, add 0.5 mmol of bismuth nitrate pentahydrate particles, stir and dissolve at room temperature for 10 min, forming a solution containing bismuth ions;

Step 2: Slowly add 10 mL (75 mmol/L) thioacetamide solution dropwise into the bismuth ion solution, and stir for 5 min at room temperature to form a bismuth-sulfur mixture;

Step 3: Put the bismuth-sulfur mixture into an ultrasonic cell pulverizer for ultrasonic reaction for 40 min, then carry out centrifugation, and the black solid obtained by centrifugation is washed 3 times respectively with deionized water and ethanol successively,

The bismuth sulfide nanospheres were prepared by vacuum drying at 20°C for 12 h.

Comparative example 1:

0.53 g bismuth nitrate pentahydrate and 0.85 g thiourea was added to 20 mL of deionized water, stirred vigorously until a uniform orange solution was formed, and continued to stir for 2 h at room temperature.

The experimental results showed that the reaction system was still a homogeneous orange solution after 2 h of reaction at room temperature, without significant change, that is, the reaction could not proceed at room temperature.

Comparative example 2:

The first step: 0.53 g bismuth nitrate pentahydrate and 0.85 g thiourea was added to 20 mL of deionized water, and stirred vigorously until a uniform orange solution was formed;

The second step: reflux reaction at 80° C. for 2 hours to obtain a brown-black precipitate. After the reaction, it was naturally cooled to room temperature, centrifuged, washed with deionized water and ethanol three times respectively, and vacuum-dried at 30 °C for 12 h to prepare bismuth sulfide nanomaterials.

The experimental results show that the reaction only occurs at 80°C, and the bismuth sulfide obtained has a large particle size and no fixed morphology.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and can also be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. Variations.

Claims (6)

1. the room temperature aqueous phase preparation method of a bismuth sulfide nano ball, it is characterised in that comprise the steps:

The first step: be dissolved in the aqueous solution that 1 ~ 30 mg/mL contains surfactant by 20 ~ 100 mmol/L chelating agen, is subsequently added five nitric hydrate bismuths, stirring and dissolving under room temperature；

Second step: 50 ~ 1800 mmol/L sulfur-bearing regent solution are added drop-wise in the mixed liquor of the first step, stir under room temperature；

3rd step: by the product of second step through water-bath temperature control, ultrasonic reaction or microwave reaction 10 min ~ 24 h, is then centrifuged processing and dried, obtains bismuth sulfide nano ball.

The room temperature aqueous phase preparation method of bismuth sulfide nano ball the most according to claim 1, it is characterised in that: described chelating agen refers to mannitol or nitrilotriacetic acid.

The room temperature aqueous phase preparation method of bismuth sulfide nano ball the most according to claim 1, it is characterised in that: in described five nitric hydrate bismuths, the substance withdrawl syndrome of bismuth nitrate is 20 ~ 100 mmol/L.

The room temperature aqueous phase preparation method of bismuth sulfide nano ball the most according to claim 1, it is characterised in that: described surfactant refers to one or more mixture in polyvinyl alcohol, polyvinylpyrrolidone, Polyethylene Glycol or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide).

The room temperature aqueous phase preparation method of bismuth sulfide nano ball the most according to claim 1, it is characterized in that: in described second step, sulfur-bearing regent refers to sodium sulfide, thioacetamide or sodium thiosulfate, the concentration of described sulfur-bearing regent is 50 ~ 1800 mmol/L, stirs 5 min at room temperature 25 DEG C.

The room temperature aqueous phase preparation method of bismuth sulfide nano ball the most according to claim 1, it is characterised in that: described centrifugal treating is the velocity process 10 minutes with 8000 ~ 10000 revs/min, and described dried refers to 30 DEG C of vacuum drying 12h.