CN100386844C

CN100386844C - Method for preparing tin dioxide quantal-point

Info

Publication number: CN100386844C
Application number: CNB2006100497490A
Authority: CN
Inventors: 祝洪良; 于桂霞; 姚奎鸿
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU; Zhejiang University of Science and Technology ZUST
Priority date: 2006-03-08
Filing date: 2006-03-08
Publication date: 2008-05-07
Anticipated expiration: 2026-03-08
Also published as: CN1831083A

Abstract

The present invention discloses a method for preparing tin dioxide quantum dots, which comprises the following steps: butter of tin is put into deionized water and is stirred, hydrazine hydrate of which the mole number is 4 to 8 times more than that of the butter of tin is then added, and at this moment, white slurry precipitation is generated, i.e., a coordination compound is formed between the hydrazine hydrate and the butter of tin; after stirred for 10 to 30 minutes, the prepared water solution is put into an autoclave, wherein the compactedness is 80 to 90%, the processing temperature is 150 to 250 DEG C, and the processing time is 1 to 50 hours; then, processed solution is centrifugated and dried, and SnO2 quantum dots are obtained. The present invention adopts hydrazine hydrate to substitute sodium hydroxide or ammonia water, a coordination compound cluster is formed from hydrazine hydrate and SnCl4, the cluster is very little, and the whole hydrothermal synthesis process of SnO2 is limited in the cluster. Moreover, the present invention uses cheap chemicals as raw materials, and the whole process does not need any complexing agent or surface active agent. The present invention has the advantages of simpleness, low prices and suitability for large-scale production.

Description

A kind of tin dioxide quanta point preparation method

Technical field

The present invention relates to a kind of tin dioxide quanta point preparation method.

Background technology

When the size of nano material is reduced to a certain degree, tangible quantum size effect has just appearred, near its Fermi level electron energy level is by the quasi-continuous discrete energy levels that changes into, its energy gap broadens simultaneously, and cause significantly different (the P.M.Petroff etal.Phys.Today of characteristic such as nano material light, magnetic, heat, electricity, catalysis thus with the body material, 54,46 (2001)).With regard to semi-conducting material, when size less than or be equivalent to itself exciton Bohr radius, will show tangible quantum effect.When the size of semiconductor nanoparticle on three-dimensional during all less than its exciton Bohr radius, this nano particle is called as quantum dot, and it all has a wide range of applications at key areas such as electronics, photoelectron, catalysis and sensings.

Tin ash (SnO ₂) be a kind of important n type oxide semiconductor, energy gap is about 3.6eV under the room temperature, and is extremely wide in applications such as invented solid gas sensing device, transparency conductive electrode, catalysis, lithium battery and opto-electronic devices.According to people such as Lee, SnO ₂The exciton Bohr radius be about 2.7 nanometers (E.J.H.Lee et al.Appl.Phys.Lett., 84,1745 (2004)).Therefore, if SnO ₂The size of nano particle less than or during near 2.7 nanometers, this nano particle is exactly SnO ₂Quantum dot.SnO ₂Quantum dot is expected to have more performance and more purposes, and exploitation preparation method simple, low-cost and suitable suitability for industrialized production synthesizes SnO ₂Quantum dot is its research and key in application.

SnO ₂Nano material is subjected to paying close attention to widely, has become one of maximum several oxide-based nanomaterials of research.At present, preparation SnO ₂The method of nano material mainly contains: spray pyrolysis, hydro thermal method, evaporation, chemical vapour deposition technique and quick oxidizing process etc.But about SnO ₂The report of quantum dot preparation is very few, and people such as Castillo have reported the SnO with sol-gel process preparation 2～5 nanometers ₂Quantum dot (J.D.Castillo et al.Nanotechnology, 16, S300 (2005)), people such as Leite have reported and have adopted hydrolysis SnCl in ethanolic solution ₂2H ₂The SnO of method preparation 1～3 nanometer of O ₂Quantum dot (E.R.Leite, Appl.Phys.Lett., 83,1566 (2003)).Though hydro thermal method is widely used in SnO ₂Synthesizing of nanostructure, but up to the present, the someone reports and adopts hydro thermal method to realize SnO as yet ₂Synthesizing of quantum dot.

It is mineralizer that traditional hydro thermal method adopts NaOH or ammoniacal liquor, and its process is as follows: the OH that NaOH or ammoniacal liquor ionization go out ^-Ion, OH ^-With Sn ⁴⁺Ionic reaction generates Sn (OH) ₄, Sn (OH) ₄Under hydrothermal condition, change SnO into ₂Hydrazine hydrate is a kind of chemical raw material commonly used, cheap, and as reducing agent, simultaneously, it can ionization go out OH usually ^-, promptly also can make mineralizer.If with the hydrazine hydrate is mineralizer, hydro-thermal is synthesized SnO ₂Process as follows: before the hydro-thermal reaction, hydrazine (ligand) and SnCl ₄Form complex bunch, this coordination thing slow reaction bunch under hydrothermal condition generates SnO ₂Quantum dot.Therefore, with the hydrazine hydrate be the size that the hydro-thermal technology of mineralizer can reduce product greatly.

Summary of the invention

The object of the present invention is to provide a kind of tin dioxide quanta point preparation method, utilize hydrazine hydrate to synthesize tin dioxide quantal-point (2.3～3.1 nanometer) for the hydro-thermal technology of mineralizer.

The technical solution used in the present invention is that the step of this method is as follows:

Butter of tin is put into deionized water for stirring, adding molal quantity again is the hydrazine hydrate of 4～8 times of butters of tin, produce the precipitation of white pulpous state this moment, be to have formed complex between hydrazine hydrate and the butter of tin, stir and the above-mentioned aqueous solution for preparing put into autoclave in 10～30 minutes that compactedness is 80～90%, treatment temperature is 150～250 ℃, processing time is 1～50 hour, with solution centrifugal, the drying handled well, just obtains tin dioxide quantal-point then.

Described tin dioxide quantal-point diameter is 2.3～3.1 nanometers, and most particle diameter is less than 2.7 nanometers, and the exciton Bohr radius of tin ash is 2.7 nanometers.

The beneficial effect that the present invention has is: traditional hydro thermal method is difficult to realize SnO ₂Synthesizing of quantum dot, method that this invention proposes is effectively with SnO ₂Nanoparticle size drops to below 3 nanometers.Maximum characteristics of the present invention are to adopt hydrazine hydrate (N ₂H ₄H ₂O) replace NaOH or ammoniacal liquor, hydrazine hydrate (ligand) and SnCl ₄Form complex bunch (SnCl ₄) _m(N ₂H ₄) _n, this bunch very tiny (being about several nanometers), and whole SnO ₂The hydro-thermal building-up process carry out in all being limited in bunch, therefore obtained SnO ₂Quantum dot.And the raw material that the present invention adopts all is cheap chemicals, and whole process need not any complexing agent or surfactant, and it is simple, cheap that the present invention has, and can be fit to large-scale production.

Description of drawings

Fig. 1 is SnO ₂The XRD figure spectrum of quantum dot;

Fig. 2 is SnO ₂The transmission electron microscope photo of quantum dot, (a) photo and electronic diffraction; (b) high-resolution photo.

Embodiment

Embodiment 1:

With 2.2400 gram butter of tin (SnCl ₄5H ₂O, 0.0064 mole) put into 160 ml deionized water, add 1.2800 gram hydrazine hydrate (N again ₂H ₄H ₂O, 0.0256 mole), stir after 10 minutes, the above-mentioned solution for preparing to be put in the polytetrafluoroethyllining lining of autoclave, the liner volume is 200 milliliters, promptly compactedness is 80%.This solution was handled 10 hours down at 150 ℃, solution centrifugal of handling well and drying, obtained SnO ₂Quantum dot.Fig. 1 is SnO ₂The XRD figure spectrum of quantum dot is with SnO ₂Standard card (JCPDS 77-0452) fit like a glove, illustrate that product is pure SnO ₂Fig. 2 a is SnO ₂The transmission electron microscope photo of quantum dot and electron diffraction pattern, Fig. 2 b are their high-resolution photos, and the product of gained is the nano particle of 2.3～3.1 nanometers as can be seen from Fig. 2 a and Fig. 2 b.

Embodiment 2:

With 2.2400 gram stannic chloride (SnCl ₄5H ₂O, 0.0064 mole) put into 180 ml deionized water, add 1.9200 gram hydrazine hydrate (N again ₂H ₄H ₂O, 0.0390 mole), stir after 20 minutes, the above-mentioned solution for preparing to be put in the polytetrafluoroethyllining lining of autoclave, the liner volume is 200 milliliters, promptly compactedness is 90%.This solution was handled 30 hours down at 200 ℃, solution centrifugal of handling well and drying, obtained SnO ₂Quantum dot.

Embodiment 3:

With 2.2400 gram stannic chloride (SnCl ₄5H ₂O, 0.0064 mole) put into 160 ml deionized water, add 2.5600 gram hydrazine hydrate (N again ₂H ₄H ₂O, 0.0512 mole), stir after 30 minutes, the above-mentioned solution for preparing to be put in the polytetrafluoroethyllining lining of autoclave, the liner volume is 200 milliliters, promptly compactedness is 80%.This solution was handled 50 hours down at 250 ℃, solution centrifugal of handling well and drying, obtained SnO ₂Quantum dot.

Claims

1. tin dioxide quanta point preparation method, the step that it is characterized in that this method is as follows: butter of tin is put into deionized water for stirring, adding molal quantity again is the hydrazine hydrate of 4～8 times of butters of tin, produce the precipitation of white pulpous state this moment, be to have formed complex between hydrazine hydrate and the butter of tin, stir and the above-mentioned aqueous solution for preparing put into autoclave in 10～30 minutes, compactedness is 80～90%, treatment temperature is 150～250 ℃, processing time is 1～50 hour, then with the solution centrifugal of handling well, drying just obtains tin dioxide quantal-point.

2. a kind of tin dioxide quanta point preparation method according to claim 1 is characterized in that: described tin dioxide quantal-point diameter is 2.3～3.1 nanometers, and the exciton Bohr radius of tin ash is 2.7 nanometers.