CN101143791A - Technique for synthesizing bismuth oxide/copper chromite core-shell structure composite nano material - Google Patents

Abstract

The invention relates to a synthesis technique of a nano composite material with a bismuth oxide and copper chromite (Bi2O3Cu-Cr-O) core-shell structure. A monodisperse spherical nano Bi2O3 colloidal particle is used as a template, an active ammonium group (<NH><4+>) is first applied on the surface of Bi2O3, which is then costed with a <Cu(NH3)4><2+> layer by utilizing the cooperative function between the <NH><4+> and the <Cu><2+>, the <Cr><3+> is directionally deposited on the surface of the Bi<SUB>2</SUB>O<SUB>3</SUB> particle by further utilizing the electrostatic gravitation between ammoniate copper <Cu(NH3)4><2+> and <Cr(OH)4><-> and properly goes through a high-temperature annealing process, and finally, the monodisperse spherical nano composite particle with the(Bi2O3/Cu-Cr-O) core-shell structure is prepared. The invention is characterized in 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 specific application requiring.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 make 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, multiple catalyzer organically can also 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.As seen, 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 the new function material that a class has 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 Bi2O3 colloidal particle is template, earlier at Bi ₂O ₃Ammonium (NH is introduced on the surface ₄ ⁺) active group, utilize NH then ₄ ⁺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 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 dehydrated 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 continues constant temperature stirring 1 hour, room temperature ageing 5 hours about 8.Then 60 ℃ of waters bath with thermostatic control with under constantly stirring, slowly be added dropwise to the Cu (NO of a certain amount of 0.05mol/L earlier in the mixing suspension ₃) ₂Solution.In this process, constantly control the pH value of mixed system about 8 with 5% ammoniacal liquor.Treat Cu (NO ₃) ₂After interpolation finishes, continue constant temperature water bath and stirring 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 is constantly controlled the pH value of mixed system about 8 with 5% ammoniacal liquor in this process.Treat Cr (NO ₃) ₃After interpolation finishes, continue constant temperature water bath and stirring 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 ₂O ₃/ Cu-Cr-O nucleocapsid structure composite nanoparticle.

Claims (1)

1. the synthesis technique of bismuth oxide/copper chromite 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 ₃Ammonium NH is introduced on the surface ⁴⁺Active group utilizes NH then ⁴⁺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.