CN105689701A

CN105689701A - Rapid preparation method of AU@Cu2O nanocomposite in yolk-shell structure

Info

Publication number: CN105689701A
Application number: CN201410703374.XA
Authority: CN
Inventors: 刘其生; 李村成; 张涛
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2014-11-26
Filing date: 2014-11-26
Publication date: 2016-06-22
Anticipated expiration: 2034-11-26
Also published as: CN105689701B

Abstract

The invention relates to a rapid preparation method of an AU@Cu2O nanocomposite in a yolk-shell structure. According to the nano material, the coverage degree of a shell layer can be controlled by regulating parameters of concentration, temperature and the like of CTAB. The preparation method comprises the following main steps: (1) adding a certain quantity of Vitamin C in mixed liquor of CuSO4.5H2O and cetyl trimethylammonium bromide (CTAB), stirring, and dissolving; (2) adding 3ml of aqueous solution of gold octahedron in the solution; (3) keeping the solution for 20min at the temperature of 60 DEG C, and then adding a certain quantity of NaOH solution dropwise; and (4) carrying out centrifugation on the obtained product, washing precipitates with deionized water and ethanol for many times, and finally dispersing in an ethanol solution. The AU@Cu2O nano material in the yolk-shell structure has very important application value in the aspects of catalysis, surface-enhanced raman scattering (SERS) and the like.

Description

A kind of AuCu of yolk-eggshell structure2The fast preparation method of O nano composite material

Technical field

The present invention relates to one and there is the AuCu of hollow yolk-eggshell (yolk-shell) structure₂The fast preparation method of O nano composite material。

Background technology

The nano composite material with yolk-eggshell (yolk-shell) structure is nucleocapsid (corevoidshell) nano material that a class has special hollow structure。The nano material of this nucleocapsid structure is because having special hollow structure, the contact area of reactant and core, shell material can be increased, it is thus possible to utilize core and the respective characteristic of shell nano material more fully, therefore, the yolk-shell nano composite material prepared by different materials can represent different characteristics so that it is has important using value in fields such as catalysis, chemical sensor, drug delivery, microreactors。The preparation method with yolk-eggshell structure nanometer composite material generally has sacrifice template, Ostwald ripening method, rear infusion process and selective etch method etc.。Wherein sacrificing template is construct a kind of method that yolk-shell structure is most widely used。The method principle is first to be coated with one layer of shell easily removed (usually SiO on the surface of nuclear material₂) material, then carrying out the shell cladding of outside again, the method that last reselection is suitable removes intermediate material (such as SiO₂Layer available hydrogen fluoric acid or NaOH dissolve), thus forming the yolk-eggshell nanostructured of hollow。Although this method can successfully construct different yolk-eggshell nanostructureds, but its shortcoming is also apparent from: be first that preparation method is complex, the method at least needs to be coated with-be coated with-make empty three steps, and its process is relatively complicated tediously long；Secondly the selection of intermediate die flaggy also has strict demand: but this template can not be reacted can be coated with mutually with core material and outer shell material, and can be removed by gentle method and be unlikely to destroy other materials；Additionally, outermost shell must be loose structure, in order to make the mould material of centre can penetrate in the molten process that disappears and remove outside shell。But sacrifice template at preparation AuCu₂But some difficulties are encountered: if primary difficulty is to select conventional SiO during O yolk-eggshell structure₂As when sacrificing template, it is typically used for ammonia as catalyst, and it can with Cu₂O forms easily oxidized unstable Cu(NH₃)₂ ⁺Complex ion and finally destroy Cu₂O shell structurre；Secondly SiO is being dissolved₂The HF of Shi Changyong also can to Cu₂O has dissolution；Furthermore, Cu₂Cu in O⁺Mediate valence state, poor stability own, is not easy to the nano material adopting the method for high-temperature maturing to prepare hollow structure。Therefore, preparation has the AuCu of yolk-eggshell structure₂O also exists certain technical difficulty, it is necessary to explore a kind of simple, quick, easy preparation method。

Summary of the invention

A kind of AuCu with yolk-eggshell structure has been invented in technical problem is that of present invention mainly solves₂The simple and quick preparation method of O nano composite material, the new technique ways and means for obtaining the nano composite material of the different yolk-eggshell structure of synthesis has carried out useful exploration。

The AuCu of mesolecithal of the present invention-eggshell structure₂The building-up process mild condition of O nano composite material, the reagent of employing is gold chloride (HAuCl₄), PDDA (PDDA), copper sulfate (CuSO₄), the conventional reagent such as cetyl trimethylammonium bromide (CTAB) and ethylene glycol。

Described yolk-eggshell structure AuCu₂The preparation method of O nano composite material, big antibody preparation procedures is as follows:

1. the preparation of gold octahedron nanoparticle

The octahedral synthetic method being prepared by thermal reduction of gold。General step is at certain density HAuCl₄Ethylene glycol solution (concentration is generally 0.50mmol/L) adds PDDA (PDDA) as nanoparticle stabilizer and morphology control agent, above-mentioned solution seals after thorough mix-ing and is placed in 220 DEG C of oil bath pans and reacts two hours, in course of reaction, the color of solution is by the original faint yellow aubergine that gradually becomes, and last solution is cooled to room temperature。

2. the preparation of gold octahedron aqueous solution

The preparation of the octahedra aqueous solution of gold adopts the mode of solvent displacement to carry out, it is therefore an objective to removes unnecessary PDDA and makes gold octahedron be distributed in aqueous systems。The octahedra ethylene glycol solution of gold obtains golden octahedral solid product by centrifugal, and general deionized water is ultrasonic again disperses for centrifugal gained precipitation, then repeats, with deionized water wash at least 3 times, to finally obtain the octahedra aqueous solution of mauve gold。

3. the AuCu of yolk-eggshell structure₂The preparation of O

The AuCu of yolk-eggshell structure₂The preparation process of O is by adopting the CTAB micelle formed to carry out the formation of control structure as soft template。The suitable concentration (0.1-0.13mol/L) of CTAB can form it into certain micellar structure, and the gold of addition is octahedra due to effect positively charged for cationic surfactant PDDA itself, it is possible to by the Br of Preferential adsorption negative charge^-, again through with Cu²⁺Electrostatic interaction layer assembly formed shell structurre, thus in follow-up reaction formed hollow structure。Experimental procedure substantially is: weigh 0.01gCuSO₄·5H₂O is dissolved in 20ml variable concentrations cetyl trimethylammonium bromide (CTAB) solution, then in solution, 0.036g vitamin C is added as reducing agent, it is sufficiently stirred for dissolving, add the 3ml variable concentrations octahedral aqueous solution of gold (concentration is 0.5-1.5mmol/L) subsequently, solution is heated to 60 DEG C and keeps 20 minutes, being eventually adding the NaOH solution of 2ml0.20mol/L, the centrifugal ionized water of products therefrom and washing with alcohol repeatedly, are finally distributed in alcoholic solution。

Beneficial effects of the present invention:

(1) the maximum feature of this preparation method is one-step synthesis method, and process is simple, mild condition, it is to avoid the experiment condition of traditional preparation process prepare the tediously long complexity of yolk-shell nano composite material and harshness；

(2) preparation is the method overcomed with Cu₂O is the technology barrier that the hollow nano composite material of shell faces, it is to avoid some conventional reagents adopted in making null process are (such as HF, NH₃·H₂O) and high temperature can to Cu₂The destroying infection that O itself causes, adopts the CTAB micelle formed to prepare hollow AuCu as gentle template one step₂O nano material；

(3) the yolk-eggshell structure AuCu that prepared by the method₂O nano material, its pattern is comparatively regular, and aerial stability is better；

(4) AuCu₂O Hollow Nanoparticles has good dispersibility and stability in the solution such as water or ethanol, and long-time preservation is not susceptible to deformation or rotten, is prone to ultrasonic disperse, not easily reunites after precipitation；

(5) AuCu₂O Hollow Nanoparticles has stronger absorption in visual field, at the wide absworption peak correspondence Cu of 300-500 nanometer (nm)₂The absorption of O, the absorption at about 700nm is gold octahedron and Cu₂There is surface plasma body resonant vibration and absworption peak after the red shift that occurs in O, spectral red shift can be carried out Effective Regulation by changing golden octahedral amount；

(6) this preparation method only needs common equipment, it is not necessary to special equipment, and technical process is simple to operation, and preparation process is quick。

Accompanying drawing explanation

Fig. 1 is to obtained Cu₂Transmission electron microscope photo (Fig. 1 a) of O hollow ball and uv-visible absorption spectra (Fig. 1 b)。Wherein monodispersed Cu₂O hollow nano-sphere JEOL-1400 transmission electron microscope observing shoots, it can be seen that prepared Cu from electromicroscopic photograph₂O nanosphere has hollow-core construction, and the size of product is comparatively uniform, and the scale in figure is 200nm。Absorption spectrum from Fig. 1 b is it can be seen that Cu₂The absorption of O hollow nano-sphere extends to the visual field of nearly 500nm from ultra-violet (UV) band, and this is Cu₂The characteristic absorption band of O；

Fig. 2 is that the concentration of CTAB controls at 0.13mol/L, to add golden octahedral amount be 3ml(0.5mmol/L) time prepared AuCu₂The transmission electron microscope photo of O Hollow Nanoparticles, wherein scale yardstick respectively 500nm and the 200nm of 2a and 2b, can be seen that from Electronic Speculum figure, it is possible to form the AuCu with hollow structure₂O nanosphere, but also having a lot of nanoparticles is Cu₂The hollow ball of O, the octahedral amount of gold of this explanation nucleation is also very little；

Fig. 3 is that the concentration of CTAB controls at 0.13mol/L, to add golden octahedral amount be 3ml(1.0mmol/L) time prepared AuCu₂The transmission electron microscope photo of O Hollow Nanoparticles, wherein scale yardstick respectively 500nm and the 200nm of 3a and 3b, it can be seen that define the AuCu of more hollow structure from Electronic Speculum figure₂O nanosphere, but still have minority Cu₂The hollow ball of O；

Fig. 4 is that CTAB concentration controls at 0.13mol/L, to add golden octahedral amount be 3ml(1.5mmol/L) time prepared AuCu₂The transmission electron microscope photo of O Hollow Nanoparticles, it can be seen that be almost completely formed the AuCu of hollow structure from Electronic Speculum figure₂O nanosphere, nanosphere size is in the scope of 100-200nm, and in relatively regular spherical, its dispersibility is better；

Fig. 5 uses the Japan's ShimadzuUV-3101PC type ultraviolet-visible-near infrared spectrometer (UV-VIS-NIR) abosrption spectrogram to made sample, and wherein, vertical coordinate is absorption intensity, and abscissa is optical wavelength。It can be seen that the AuCu of the yolk-shell structure formed₂O nano-particle has stronger absworption peak in 450 and 700nm place, and wherein the wide absworption peak at 450nm place is Cu₂The characteristic absorption peak of O hollow ball, and be the octahedral absworption peak of gold after occurring surface plasma body resonant vibration to cause red shift at the absworption peak of 700 nanometers。

Detailed description of the invention

Agents useful for same is the conventional medication bought in Reagent Company。The preparation of aqueous solution selects 18 megaohms of deionized waters: (PDDA, (400,000) are made into 1.25mol/L aqueous solution, gold chloride (HAuCl to PDDA₄) be made into the aqueous solution of 1.0mol/L, cetyl trimethylammonium bromide (CTAB) is made into the aqueous solution of 0.2mol/L, NaOH is made into the aqueous solution of 0.2mol/L。

Below in conjunction with being embodied as example, present disclosure is described in further detail。

Experiment embodiment

1. the preparation of gold octahedron nanoparticle

Vial adds the HAuCl of 1mol/L₄Solution 35 μ L, is subsequently adding 70mL ethylene glycol, adds 1.40mL PDDA (PDDA) (400,000,1.25mol/L), each composition ultimate density: HAuCl in system₄: 0.50mmol/L, PDDA:25mmol/L。Above-mentioned solution is placed in 220 DEG C of oil bath pans after thorough mix-ing and reacts two hours, finally room temperature in cooling。The color of solution faint yellow is become aubergine from original。

2. the preparation of gold octahedron aqueous solution

The centrifugation in high speed centrifuge in centrifuge tube of depletion octahedron ethylene glycol solution, under 8000-10000 rev/min of condition of rotating speed after centrifugal 20 minutes, remove colourless solution in centrifuge tube, add after deionized water ultrasonic disperse centrifuge washing again, repeat this process with water to wash 3 times, finally obtain the octahedra aqueous solution of mauve gold。

3. the AuCu of yolk-eggshell structure₂The preparation of O

Weigh 0.01gCuSO₄·5H₂It is 0.13mol/L cetyl trimethylammonium bromide (CTAB) solution that O is dissolved in 20ml concentration, then in solution, add 0.036g vitamin C, it is sufficiently stirred for so as to dissolve, add the 3ml octahedral aqueous solution of gold (concentration is 0.5-1.5mmol/L) subsequently, solution is heated to 60 DEG C and keeps 20 minutes, it is subsequently added the NaOH solution of 2ml0.20mol/L, solution presents green at once, last gained solution is centrifuged 10 minutes under 8000 revs/min, gained precipitation uses deionized water and ethanol centrifuge washing repeatedly successively, is finally distributed in alcoholic solution。

Claims

1. there is the AuCu of yolk-eggshell structure₂O hollow nanometer material, it is characterised in that:

(1) AuCu prepared by₂O nano material has the eggshell-egg yolk nanostructured of hollow, and its particle diameter is approximately between 100-200nm, and pattern is comparatively regular；

(2)AuCu₂O Hollow Nanoparticles has good dispersibility and stability in the solution such as water or ethanol, and long-time preservation does not deform upon or rotten, is prone to ultrasonic disperse, not easily reunites after precipitation；

(3)AuCu₂The pattern of O Hollow Nanoparticles and coverage degree can carry out Effective Regulation by the control octahedral concentration of CTAB and Au。

2. a claim has the AuCu of yolk-eggshell structure₂The fast preparation method of O hollow nanometer material, is characterized in that comprising the following steps:

(1) a certain amount of CuSO is weighed₄·5H₂It is 0.13mol/L cetyl trimethylammonium bromide (CTAB) solution that O is dissolved in concentration, then adds 0.036g vitamin C in solution, is sufficiently stirred for so as to dissolve；

(2) after solution is sufficiently mixed, adds the 3ml octahedral aqueous solution of gold (concentration is 0.5-1.5mmol/L), stirs；

(3) solution is heated to 60 DEG C and keeps 20 minutes at such a temperature, is subsequently added the NaOH solution of 2ml0.20mol/L, and solution presents green at once；

(4) gained solution centrifuge 10 minutes, rotating speed controls at about 8000 revs/min, and precipitation with deionized water and ethanol centrifuge washing repeatedly, is finally distributed in alcoholic solution successively。

3. preparation method according to claim 2, it is characterised in that adopt CTAB micelle to prepare the AuCu of yolk-eggshell structure as soft template one-step method quickly and easily₂O nano material, what surfactant adopted is cetyl trimethylammonium bromide。

4., according to the preparation method described in claim 2, it is characterized in that in reaction precursor liquid solution that the concentration of CTAB controls 0.1-0.13 mol/L and be advisable。

5. according to the preparation method described in claim 2, its characteristic reaction temperature is 60 DEG C, and the response time is 20min。

6. according to the preparation method described in claim 2, reducing agent is vitamin C (i.e. ascorbic acid), and precipitant selects NaOH aqueous solution, and its concentration is 0.2 mol/L。

7., according to the preparation method described in claim 2, it is characterized in that the solvent of washing and precipitating product is deionized water or dehydrated alcohol。