CN101143791B

CN101143791B - Technique for synthesizing bismuth oxide/copper chromite core-shell structure composite nano material

Info

Publication number: CN101143791B
Application number: CN2006100322299A
Authority: CN
Inventors: 李卫; 卢周广; 万伟华; 程化; 杨华
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2006-09-13
Filing date: 2006-09-13
Publication date: 2012-07-25
Anticipated expiration: 2026-09-13
Also published as: CN101143791A

Abstract

The invention relates to a synthesis technique of a bismuth oxide/copper chromite (Bi2O3Cu-Cr-O) core-shell structure nano composite material. A monodisperse spherical nano Bi2O3 colloidal particle is used as a template, an active ammonium group (NH<4+>) is first induced on the surface of Bi2O3, then a Cu(NH3)4<2+> layer is coated on the Bi2O3 surface by utilizing the cooperative function between the NH<4+> and the Cu<2+>, further the Cr<3+> is directionally deposited on the surface of the Bi2O3 particle by utilizing the electrostatic attraction between ammoniate copper Cu(NH3)4<2+> and Cr(OH)4<->, finally the monodisperse spherical (Bi2O3/Cu-Cr-O) core-shell structure nano composite particle is prepared and obtained after a proper high-temperature annealing process. The invention has characteristics of simple and facile materials, simple production technique, low cost, environmental protection and high product activity.

Description

The synthesis technique of bismuth oxide/copper chromite core-shell structure composite nano material

[technical field] the present invention relates to bismuth oxide/copper chromite (Bi ₂O ₃/ Cu-Cr-O) the synthesis technique of core-shell structure composite nano material.

[background technology] hud typed composite nano materials have high stability, high catalytic activity, pattern and size evenly, advantages such as composition and controllable structure; Can realize the fully effectively coupling of heterogeneity on nanoscale, and can be by artificial design and controlled preparation to satisfy many certain applications requirements.Therefore in recent years, hud typed composite nano materials has caused people's extensive concern.The composite particles that the nucleocapsid composite particles is made up of at least two kinds of different substancess, and normally wherein a kind of material forms nuclear, another kind of material formation outer shell.Catalyzer is mixed the compound form with organic/inorganic process the hollow core-shell particulate material; Not only can increase substantially activity of such catalysts; And can utilize sterically hindered, the mapping structure of organic shell and the influence of electrostatic interaction to realize selectivity catalysis, can also multiple catalyzer organically be integrated in the system sometimes.Bismuth oxide (Bi ₂O ₃) and copper chromium composite oxides (Cu-Cr-O) have a wide range of applications at key areas such as catalyzer, electronic ceramics and solid electrolytes.Thus it is clear that, with Bi ₂O ₃Be prepared into the composite nano materials of nucleocapsid structure with Cu-Cr-O; Be expected to fully utilize the intrinsic property of each constituent materials and develop one type of new function material with special performance; And abundant and developed the academic intension of colloid and interface science, thereby have great importance.

[summary of the invention] the objective of the invention is to overcome inferior complex acid copper of nanometer and the easy technological difficulties of reuniting of nano bismuth oxide; And provide a kind of raw material to be simple and easy to, and production technique is simple, and cost is low; Environment protection standard, the active height of product and the liquid chemical method of controllable granularity prepares bismuth oxide/copper chromite (Bi ₂O ₃/ Cu-Cr-O) the method for core-shell structure composite nano material.

Concrete technological process is: with spherical dispersed nano Bi ₂O ₃Colloidal particle is a template, earlier at Bi ₂O ₃Surface introducing ammonium (

Figure S06132229920060929D00001094858QIETU

) reactive group, utilize then

Figure S06132229920060929D00001094914QIETU

With Cu ²⁺Between mating reaction at Bi ₂O ₃The surface coats goes up [Cu (NH ₃) ₄] ²⁺Layer further utilizes ammino copper [Cu (NH then ₃) ₄] ²⁺With [Cr (OH) ₄]-between the electrostatic attraction effect, with Cr ³⁺Orientated deposition is at Bi ₂O ₃Particle surface, suitably high temperature annealing prepares spherical monodispersed Bi at last ₂O ₃/ Cu-Cr-O nucleocapsid structure composite nanoparticle.

[embodiment]

Take by weighing 0.01molBi (NO ₃) ₃6H ₂O is dissolved in the HNO of 30mL0.005mol/L ₃Obtain transparent Bi ³⁺Solution.The NaOH solution for standby of configuration 4mol/L concentration.Under the condition of 90 ℃ of waters bath with thermostatic control, toward Bi ³⁺Slowly add 20mL polyoxyethylene glycol (PEG8000) dispersion agent in the solution, stir.After continue stirring 30min, the NaOH solution of 50ml4mol/L is injected in the mixing solutions, transparent mixed solution is converted into lurid suspension-s at once.Continue vigorous stirring 2h 90 ℃ of waters bath with thermostatic control then.The gained light-yellow precipitate with the centrifugal recovery of the speed of 24000r/s, is used absolute ethyl alcohol, acetone and deionized water wash respectively repeatedly.At 60 ℃ of vacuum-drying 5h, promptly obtain the nano bismuth oxide product.

Get a certain amount of freshly prepd dispersed nano Bi ₂O ₃Colloidal particle is earlier with deionized water wash number time, adds that ultra-sonic dispersion obtained lurid soliquid in 1 hour in the 100mL Virahol.Then under 60 ℃ of waters bath with thermostatic control and high degree of agitation, add ammoniacal liquor and the 20mL deionized water of 20mL5% in the mixing suspension, the pH value of control mixed system about 8, continuation constant temperature stirring 1 hour, room temperature ageing 5 hours.Then 60 ℃ of waters bath with thermostatic control with constantly stir down the first Cu (NO that slowly is added dropwise to a certain amount of 0.05mol/L in the mixing suspension ₃) ₂Solution.The pH value of in this process, constantly controlling mixed system with 5% ammoniacal liquor is about 8.Treat Cu (NO ₃) ₂After interpolation finishes, continue constant temperature water bath and stirred 5 hours, the room temperature ageing is 5 hours then.Then in mixed system, continue to add and Cu (NO ₃) ₂Cr (the NO of solution same amount 0.05mol/L ₃) ₃Solution, the pH value of in this process, constantly controlling mixed system with 5% ammoniacal liquor is about 8.Treat Cr (NO ₃) ₃After interpolation finishes, continue constant temperature water bath and stirred 5 hours, the room temperature ageing is 36 hours then.The mixed sediment filtered and recycled obtains the presoma of brownish black.Presoma obtained the aterrimus product in 5 hours 800 ℃ of anneal, was spherical monodispersed Bi ₂O3/Cu-Cr-O nucleocapsid structure composite nanoparticle.

Claims

1. the synthesis technique of a bismuth oxide/copper chromite (Bi2O3/Cu-Cr-O) core-shell structure composite nano material is characterized in that: with spherical dispersed nano Bi ₂O ₃Colloidal particle is a template, earlier at Bi ₂O ₃Introduce on the surface

Reactive group utilizes then

With Cu ²⁺Between mating reaction at Bi ₂O ₃The surface coats goes up [Cu (NH ₃) ₄] ²⁺Layer further utilizes ammino copper [Cu (NH then ₃) ₄] ²⁺With [Cr (OH) ₄] ^-Between the electrostatic attraction effect, with Cr ³⁺Orientated deposition is at Bi ₂O ₃Particle surface, suitably high temperature annealing prepares spherical monodispersed Bi at last ₂O ₃/ Cu-Cr-O nucleocapsid structure composite nanoparticle, concrete technology is:

With freshly prepd dispersed nano Bi ₂O ₃Colloidal particle is earlier with deionized water wash number time, adds that ultra-sonic dispersion obtained lurid soliquid in 1 hour in the 100mL Virahol, then under 60 ℃ of waters bath with thermostatic control and high degree of agitation; The ammoniacal liquor and the 20mL deionized water that add 20mL 5% in the mixing suspension; The pH value of control mixed system continues constant temperature and stirred room temperature ageing 5 hours 1 hour about 8; Then 60 ℃ of waters bath with thermostatic control with constantly stir down the first Cu (NO that slowly is added dropwise to 0.05mol/L in the mixing suspension ₃) ₂Solution; The pH value of in this process, constantly controlling mixed system with 5% ammoniacal liquor is treated Cu (NO about 8 ₃) ₂After interpolation finishes, continue constant temperature water bath and stirred 5 hours, the room temperature ageing is 5 hours then; Then in mixed system, continue to add and Cu (NO ₃) ₂Cr (the NO of solution same amount 0.05mol/L ₃) ₃Solution, the pH value of in this process, constantly controlling mixed system with 5% ammoniacal liquor is about 8; Treat Cr (NO ₃) ₃After interpolation finishes, continue constant temperature water bath and stirred 5 hours, the room temperature ageing is 36 hours then; The mixed sediment filtered and recycled obtains the presoma of brownish black; Presoma obtained the aterrimus product in 5 hours 800 ℃ of anneal, was spherical monodispersed Bi ₂O3/Cu-Cr-O nucleocapsid structure composite nanoparticle.