CN101368292A - Coordination template for ZnS or ZnSe nanometer crystal preparation and hydrothermal preparation method thereof - Google Patents

Abstract

The invention relates to a complexing template of nano ZnS or ZnSe crystal and a hydrothermal preparation method thereof. Glutin or chitosan salt is taken as the complexing template. The hydrothermal preparation method includes the following steps: heating zinc salt and complexing template agent at mass ratio of 1:1-10 for 1-8hours in water which is at mass ratio of 10-50 to zinc salt under constant temperature of 50-80 DEG C, then filtrating after cooling; adjusting the pH value to 9-12 through sodium hydroxide or ammonia, then adding sodium thiosulfate or sodium selenite at mass ratio of 0.5-5 to zinc salt; after dissolution, adding hydrazine hydrate or vitamin C at mass ratio of 0.5-10 to sodium thiosulfate or sodium selenite, after which clear and uniform solution can be obtained after dissolution; transferring the solution into a hydrothermal kettle and filling 60-90% of the hydrothermal kettle; rising the temperature to 120-240 DEG C and heating for 12-24h, then collecting the deposit and washing, after which nano crystals can be obtained. The invention takes glutin or chitosan salt which is cheap and low in toxicity as the soft template complexing agent for hydrothermal preparation of ZnS or ZnSe. In this way, nano crystals can be obtained, and adjusted to be rods or spheres in shape, with the diameter controllable within30-50nanometers and the length controllable within 20-70nanometers.

Description

The coordination template and the hydrothermal preparing process of preparation ZnS or ZnSe nanocrystal

Technical field

The invention belongs to nano material and field of nanometer technology, specifically refer to the coordination template and the hydrothermal preparing process of preparation ZnS or ZnSe nanocrystal.

Background technology

The II-VI element can component property good semi-conductor, the maximum of research are CdS, CdSe, the chalcogenide of cadmiums such as CdTe.In recent years, (Te) property research of nanocrystal (claiming quantum dot again) has shown the application prospect that it is long-range to CdE, all has broad application prospects at aspects such as immunofluorescence label, solar cell, quantum computers for E=S, Se.But Cd salt itself just has high toxicity, and building-up process also can be introduced toxic reagent, so people are also at the lower homologue of its toxicity of research.ZnSe belong to the direct transition type semiconductor material in broad stopband (～2.67eV), has wide transparency range (0.15～22.0 μ m), higher luminous efficiency, low specific absorption, in recent years, ZnSe is widely used on the materials such as laser apparatus and thin-film solar cells at photoluminescence and electroluminescent device, for example is used to prepare blue LED (LED) and Laser Devices (LD).Based on the widespread use of ZnSe material, the scientific worker has been developed the various methods that are used to prepare the ZnSe material, comprises subliming method, chemical Vapor deposition process (CVD), molecular beam epitaxy (MBE), solvent-thermal method and hydrothermal method etc.At present most widely used is nonaqueous phase colloid chemistry method, grows up from the TOP/TOPO route of Bawendi group, and these class methods utilize TOPO as the part solvent, preparation ZnE and CdE (E=S, Se, Te) nanocrystal under the high-temperature anhydrous oxygen free condition.Utilize these class methods can obtain adjustable grain, the high quality nanocrystal of high-crystallinity and high quantum fluorescent yield.But the shortcoming of this method is used solvent to cost an arm and a leg, and the toxicity height is unfavorable for large batch of production.People such as Peng have obtained cube mutually ZnSe nano particle with simple substance zinc powder and simple substance selenium powder and quadrol under 180 ℃ of insulation 24h conditions under hydrothermal condition, its mean sizes is 70～100nm, has opened up the new direction with green synthetic route-hydrothermal method synthesis of nano crystal.

The prior art close with the present invention can be referring to semi-conductor journal, 2003,24 (1), 58-62.This article has used triethylamine, diethylamine, three kinds of ligand solvents of trolamine.With a kind of ZnSO of and porphyrize wherein ₄With Se mixed powder and an amount of KBH ₄Mix, mixture adds behind the autoclave respectively in room temperature and 170 ℃ reaction 12 hours down, can correspondingly obtain spherical and 1-dimention nano ZnSe.And Beijing Institute of Technology's journal, 2004,24 (10), 932-934.This article adopts disodium ethylene diamine tetraacetate (EDTA) as the coordination template agent, and under 190 ℃ and 1.2M Pa reaction conditions, having obtained diameter is 40～70nm, and length is the ZnSe nanometer rod of 360～460nm.Part plays important effect in the reaction, and they can complexing Zn ²⁺And the formation complexing ion, in the high-temperature water thermal environment, the stability of complex compound descends gradually, makes whole system Zn ²⁺Concentration slowly discharges, thereby control ZnSe monomer concentration is regulated and control nucleation and growth velocity.Suitable part can also form laminate structure, makes Zn by coordination ²⁺The one dimension or the sequential 2 D that have are to a certain degree arranged, and help to form nanometer rod.Coordination template agent such as the employed quadrol of these background technologies, trolamine all have certain toxicity, and therefore selecting new coordination template agent for use is the emphasis of studying at present.

Summary of the invention

The purpose of this invention is to provide new coordination template agent, we have developed new hydro-thermal synthesis process for this reason, selected for use biological polyamines such as cheap gelatin or crust amine salt as the coordination template agent, when having reduced toxicity and cost, make its polygamy site and backbone can help this coordination assembling, make ZnS and ZnSe nanocrystal along the template oriented growth.

Technical scheme concrete steps of the present invention are as follows:

The present invention prepares the coordination template of ZnS and ZnSe nanocrystal, is to utilize gelatin or crust amine salt as coordination template.

Prepare the hydrothermal preparing process of ZnS and ZnSe nanocrystal with coordination template of the present invention, concrete steps are:

(1) by mass ratio be the zinc salt of 1:1～10 and coordination template agent with the zinc salt mass ratio be 50～80 ℃ of heating of constant temperature 1～8 hour in 10～50 the water, cooled and filtered;

(2) be 0.5～5 Sulfothiorine or Sodium Selenite with filtrate pH regulator to 9～12 back addings with the zinc salt mass ratio with sodium hydroxide or ammoniacal liquor; After the dissolving again adding and Sulfothiorine or Sodium Selenite mass ratio be 0.5～10 hydrazine hydrate or vitamins C, dissolving obtains clarifying uniform solution; Gained solution is moved in the water heating kettle, fill 60%～90%; Be warming up to 120～240 ℃, heating 12～24h, collecting precipitation, washing obtains nanocrystalline.

Utilize novel method provided by the invention, can obtain form, granularity are all controlled and be evenly distributed high quality ZnS and ZnSe nanocrystal.The present invention has used the gelatin of inexpensive and low toxicity or crust amine salt as ZnS and ZnSe hydro-thermal synthetic soft template complexing agent.Utilize method of the present invention, can pass through to change: the kind of zinc salt, the concentration of coordination template agent in the solution, temperature of reaction and time are waited and control the nanocrystalline globule size of gained easily, obtaining form can be in bar-shaped and spherical adjusting, controllable diameter is in 30～50 nanometers, and length controlled is nanocrystalline 20～70 nanometers.

Description of drawings

Fig. 1 is that the median size that the embodiment of the invention 1 prepares is the transmission electron microscope photo of the ZnS nanocrystal of 30nm.

Fig. 2 is that the median size that the embodiment of the invention 2 prepares is the fluorescent emission spectrogram of the ZnSe nanocrystal of 20 * 50nm.

Fig. 3 is that the median size that the embodiment of the invention 2 prepares is the powdery diffractometry spectrogram of the ZnSe nanocrystal of 20 * 50nm.

Fig. 4 is that the median size that the embodiment of the invention 2 obtains is the transmission electron microscope photo of the ZnSe nanocrystal of 20 * 50nm.

Fig. 5 is the x X-ray photoelectron spectroscopy X figure of the ZnSe nanocrystal of 20 * 50nm of preparing of the embodiment of the invention 2.

Fig. 6 is the x X-ray photoelectron spectroscopy X figure of the ZnSe nanocrystal for preparing of the embodiment of the invention 2, Zn2p narrow scan spectrum.

Fig. 7 is the x X-ray photoelectron spectroscopy X figure of the ZnSe nanocrystal for preparing of the embodiment of the invention 2, Se3d narrow scan spectrum.

Fig. 8 is the ball-type for preparing of the embodiment of the invention 3 and the transmission electron microscope photo of bar-shaped mixing ZnSe nanocrystal.

Fig. 9 is the transmission electron microscope photo of the bar-shaped ZnSe nanocrystal of 20 * 60nm of preparing of the embodiment of the invention 4.

Figure 10 is that the median size that the embodiment of the invention 5 prepares is the transmission electron microscope photo of the ZnSe nanocrystal of 50nm.

Embodiment

Following embodiment describes the present invention:

Embodiment 1:

(1) get the 1.2g zinc chloride, the 6.0g gelatin, 20mL water places round-bottomed flask, and heating for dissolving stirs, and 50 ℃ of heating of constant temperature 8h is in cooled and filtered.

(2) filtrate adds 5.0g Na ₂S ₂O ₃, contain the deionized water of 10ml of 0.04g NaOH and the 6ml hydrazine hydrate water heating kettle (pH12) of packing into, add water and be filled to 60%, sealing, and remained on 180 ℃ of temperature 16 hours.Cooled and filtered.Obtaining particle diameter is the spherical ZnS nanocrystal of 24～36nm.The TEM photo is seen Fig. 1.

Embodiment 2:

(1) get the 1.5g zinc acetate, the 2.0g gelatin, 15mL water places round-bottomed flask, and heating for dissolving stirs, and 80 ℃ of heating of constant temperature 4h is in cooled and filtered.。

(2) filtrate is regulated pH value to 11 with ammoniacal liquor, adds 3.0g Na ₂SeO ₃And the 5m1 hydrazine hydrate water heating kettle of packing into, add water and be filled to 80%, sealing, and remained on 160 ℃ of temperature 18 hours.Cooled and filtered.Obtain diameter 15～25nm, the bar-shaped ZnSe nanocrystal of bar-shaped ZnSe nanocrystal mean particle size 20 * 50nm of length 40～60nm.

Gained powder water and dehydrated alcohol flushing final vacuum drying, photoluminescence spectrum is seen Fig. 2, uses the 327nm ultraviolet excitation, and peak luminous wavelength is 450nm, and 466nm has blue shift than body material ZnSe band gap; The XRD spectrum is seen Fig. 3, finds that powder belongs to a cube phase, a=5.67

, the peak broadening appears in consistent with body material cube ZnSe (JCPDS card No.37-1463) owing to granularity is little; The TEM spectrum sees that Fig. 4, the powder morphology of preparation are the 20 * 50nm rod-shpaed particle of granularity than homogeneous; Fig. 5 is the x X-ray photoelectron spectroscopy X spectrogram that obtains powder.In sample, find to have only Zn, Se and C.Wherein, C may be that the pollutent of vacuum system causes.In the narrow scan of Zn2p and Se3d spectrum, all have only unimodal, Zn2p ³And Se3d ⁵Bound energy be respectively 1021.3 (Fig. 6) and 55.5eV (Fig. 7), respectively corresponding Zn in ZnSe ²⁺And Se ^2-Bound energy.

Embodiment 3:

(1) get 1.5g zinc sulfate, 4.0g L-glutamic acid chitosan, 60mL water places round-bottomed flask, and heating for dissolving stirs, 70 ℃ of heating of constant temperature 1h.

(2) after cooling, add the deionized water of the 10ml contain 0.10gNaOH, 4.0g Na ₂SeO ₃With the 4.0g vitamins C water heating kettle of packing into, add water and be filled to 80%, sealing, and remained on 200 ℃ of temperature 12 hours.Cooled and filtered.Obtain ball-type and bar-shaped blended ZnSe nanocrystal.The TEM photo is seen Fig. 8.

Embodiment 4:

(1) get the 1.2g zinc acetate, the 12.0g gelatin, 60mL water places round-bottomed flask, and heating for dissolving stirs, 70 ℃ of heating of constant temperature 4h.

(2) after cooling, add ammoniacal liquor and regulate pH value to 9,6.0g Na ₂SeO ₃With the 3ml hydrazine hydrate water heating kettle of packing into, add water and be filled to 90%, sealing, and remained on 120 ℃ of temperature 24 hours.Cooled and filtered.Obtain diameter 12～35nm, the bar-shaped ZnSe nanocrystal of length 40～80nm, mean particle size 20 * 60nm.The TEM photo is seen Fig. 9.

Embodiment 5:

(3) get 1.2g zinc sulfate, 1.2g hydrochloric acid chitosan, 20mL water places round-bottomed flask, and heating for dissolving stirs, 70 ℃ of heating of constant temperature 4h.

(4) after cooling, add the deionized water of the 10ml contain 0.04gNaOH, 0.6g Na ₂SeO ₃With the 6ml hydrazine hydrate water heating kettle of packing into, add water and be filled to 70%, sealing, and remained on 240 ℃ of temperature 24 hours.Cooled and filtered.Obtain the spherical ZnSe nanocrystal of granularity 40～60nm.The TEM photo is seen Figure 10.

Claims (2)

1. the coordination template of preparation ZnS and ZnSe nanocrystal is characterized in that utilizing gelatin or crust amine salt as coordination template.

2. by the described hydrothermal preparing process for preparing the coordination template of ZnS and ZnSe nanocrystal of claim 1, it is characterized in that:

(1) by mass ratio be the zinc salt of 1:1～10 and coordination template agent with the zinc salt mass ratio be 50～80 ℃ of heating of constant temperature 1～8 hour in 10～50 the water, cooled and filtered;

(2) be 0.5～5 Sulfothiorine or Sodium Selenite with filtrate pH regulator to 9～12 back addings with the zinc salt mass ratio with sodium hydroxide or ammoniacal liquor; After the dissolving again adding and Sulfothiorine or Sodium Selenite mass ratio be 0.5～10 hydrazine hydrate or vitamins C, dissolving obtains clarifying uniform solution; Gained solution is moved in the water heating kettle, fill 60%～90%; Be warming up to 120～240 ℃, heating 12～24h, collecting precipitation, washing obtains nanocrystalline.

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