CN103191716A

CN103191716A - Corundum structured composite oxide photocatalyst Mg4Nb2-xTaxO9 and preparation method thereof

Info

Publication number: CN103191716A
Application number: CN2013101323072A
Authority: CN
Inventors: 方亮; 唐莹; 韦珍海
Original assignee: Guilin University of Technology
Current assignee: Anhui Shangqian Science And Technology Information Consulting Co ltd; Guangzhou Boyi Intellectual Property Operation Co ltd
Priority date: 2013-04-17
Filing date: 2013-04-17
Publication date: 2013-07-10
Anticipated expiration: 2033-04-17
Also published as: CN103191716B

Abstract

The invention discloses a visible-light responding corundum structured composite oxide photocatalyst Mg4Nb(2-x)TaxO9 and a preparation method thereof. The chemical composition general formula of the photocatalyst is Mg4Nb(2-x)TaxO9, wherein x is not less than 0 and not more than 2. The invention also discloses the preparation method of the material. The preparation method is simple and is low in cost. The prepared photocatalyst has excellent catalytic performance, has the function of decomposing harmful chemical substances under visible light irradiation and has good stability and good application prospect.

Description

Corundum structural type compound oxide photocatalyst Mg 4Nb 2-xTa xO 9And preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded corundum structural type compound oxide photocatalyst Mg ₄Nb _2-xTa _xO ₉And preparation method thereof, belong to inorganic field of photocatalytic material.

Background technology

Along with The development in society and economy, people more and more pay close attention to for the energy and ecological environment, solve energy shortage and problem of environmental pollution and be to realize sustainable development, improve people's living standard and pressing for of safeguarding national security.

Fujishima had found TiO in 1972 ₂Semi-conducting electrode has the effect of photodissociation water under UV-irradiation, caused the research boom of conductor photocatalysis thus.Its main field comprises: (1) is the energy with the solar energy, is that oxidant impels the organic pollution in the water and air thoroughly to resolve into CO with airborne oxygen ₂, H ₂O and other inorganic salts are a kind of desirable pollutant control technologys; (2) utilizing solar energy that water decomposition is chemical energy such as hydrogen and oxygen, is the important component part of Hydrogen Energy economy; (3) directly change solar energy into electric energy.Though TiO ₂Be a kind of extremely outstanding photochemical catalyst, but because TiO ₂Energy gap big (3. 2eV), the ultraviolet light that has only wavelength to be equal to or less than 387 nm just can excite TiO ₂Thereby produce conduction band electron and valence band hole to causing light-catalyzed reaction.But the actual wave-length coverage that arrives the solar radiation energy on the face of land concentrates on 460 ~ 500nm, ultraviolet composition (300 ~ 400nm) less thaies 5%, therefore how to utilize sunshine to carry out light-catalyzed reaction efficiently, exploitation can be caused people's interest just day by day by the photochemical catalyst of excited by visible light.

In order to expand TiO ₂The response wave length scope to take full advantage of sunshine, people have carried out many study on the modification to it, comprise metal ion mixing, nonmetallic ion-doped, surface light sensitization, coupling semiconductor and introduce methods such as oxygen room, ion injection.Some scientific workers have developed a large amount of new multicomponent metal oxide visible light catalysts, bismuthous compound such as BiVO ₄, Bi ₂MoO ₆, Bi ₂Mo ₂O ₉, Bi ₂Mo ₃O ₁₂And Bi ₂WO ₄Be reported in and have good absorption under the visible light.A series of niobiums (tantalum) hydrochlorate photochemical catalyst is widely studied owing to having higher photocatalytic activity.For example, pyrochlore (pyrochlore) structural type compd B i ₂MnNbO ₇(M=Al, Ga, In or rare earth element), wolframite (wolframite) structural type compound I nMO ₄(M=Nb or Ta), Stibotantalite Wolframite structural type compd B iMO ₄The KNbO of (M=Nb or Ta) etc. and niobium potassium compound oxide photocatalyst such as layer structure ₃, KNb ₃O ₈, K ₄Nb ₆O ₁₇K with pore passage structure ₆Nb _10.6O ₃₀Deng all having photocatalysis performance preferably.

Though photocatalysis research has been carried out the several years, but at present report to have visible light-responded photochemical catalyst kind still very limited, exist still that light conversion efficiency is low, problem such as poor stability and spectrum respective range are narrow, be very necessary so research and develop the new visible light-responded high efficiency photocatalyst that has.Document [Hirotaka Ogawa, Akinori Kan, Soichi Ishihara, Yutaka Higashida. Crystal structure of corundum type Mg ₄Nb _2-xTa _xO ₉Microwave dielectric ceramics with low dielectric loss. Journal of the European Ceramic Society, 2003,23:2485 – 2488] reported corundum structural type composite oxides Mg ₄Nb _2-xTa _xO ₉Structure and microwave dielectric property.Consider the research report that does not still have relevant this compounds photocatalysis performance at present, we are to Mg ₄Nb _2-xTa _xO ₉Carried out Photocatalytic Performance Study, found that this compounds has the photocatalysis performance of excellent visible light response.

Summary of the invention

The purpose of this invention is to provide a kind of visible light-responded corundum structural type compound oxide photocatalyst Mg that has ₄Nb _2-xTa _xO ₉And preparation method thereof.

The chemical composition general formula with visible light-responded corundum structural type composite oxides that the present invention relates to is: Mg ₄Nb _2-xTa _xO ₉, 0≤x≤2 wherein.

Preparation method's concrete steps of described corundum structural type composite oxides are:

(1) with 99.9% analytically pure chemical raw material MgO, Nb ₂O ₅And Ta ₂O ₅, press Mg ₄Nb _2-xTa _xO ₉Chemical formula weigh batching, wherein 0≤x≤2.

(2) step (1) confected materials is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours mixes levigately, takes out oven dry, 200 mesh sieves.

(3) powder that step (2) is mixed is 1250 ~ 1350 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by pulverizing means such as ball mills particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄Nb _2-xTa _xO ₉Powder.

Preparation method of the present invention is simple, cost is low, and the photochemical catalyst of preparation has excellent catalytic performance, has the effect of decomposing harmful chemical, organic-biological matter and sterilization under radiation of visible light.

The specific embodiment

To be specifically described the present invention below:

1, in order to obtain employed composite oxides among the present invention, at first use solid-phase synthesis to prepare powder, namely various oxides or carbonate as raw material are mixed according to target composition stoichiometric proportion, synthetic in air atmosphere under normal pressure again.

2, in order effectively to utilize light, the size of the photochemical catalyst among the present invention is preferably in micron level, or even nano particle, and specific area is bigger.With the oxide powder of solid-phase synthesis preparation, its particle is big and surface area is less, but can particle diameter be diminished by pulverizing means such as ball mills.

3, as the simulation organic pollution, its concentration is 20mg/L with methyl orange in photocatalysis experiment of the present invention; Corundum structural type compound oxide photocatalyst Mg ₄Nb _2-xTa _xO ₉Addition be 1g/L; Light source uses the xenon lamp of 300W, and the vessel that reactive tank uses pyrex to make obtain wavelength greater than 420nm long wavelength's light by wave filter, then the irradiates light catalyst; The catalysis time set is 120 minutes.

Embodiment 1:

(1) with 99.9% analytically pure chemical raw material MgO and Ta ₂O ₅, press Mg ₄Ta ₂O ₉The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1350 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by ball mill pulverizing means particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄Ta ₂O ₉Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.3% to the methyl orange clearance in 120 minutes.

Embodiment 2:

(1) with 99.9% analytically pure chemical raw material MgO and Nb ₂O ₅, press Mg ₄Nb ₂O ₉The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1250 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by ball mill pulverizing means particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄Nb ₂O ₉Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.7% to the methyl orange clearance in 120 minutes.

Embodiment 3:

(1) with 99.9% analytically pure chemical raw material MgO, Nb ₂O ₅And Ta ₂O ₅, press Mg ₄NbTaO ₉The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1300 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by ball mill pulverizing means particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄NbTaO ₉Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.6% to the methyl orange clearance in 120 minutes.

Embodiment 4:

(1) with 99.9% analytically pure chemical raw material MgO, Nb ₂O ₅And Ta ₂O ₅, press Mg ₄Nb _0.5Ta _1.5O ₉The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1320 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by ball mill pulverizing means particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄Nb _0.5Ta _1.5O ₉Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.1% to the methyl orange clearance in 120 minutes.

The present invention never is limited to above embodiment.Have with the element of Mg analog structure and chemical property such as Co, Zn etc. and also can make photochemical catalyst with analogous crystalline structure of the present invention and performance.Each composition, the bound of temperature, interval value can both realize the present invention, do not enumerate embodiment one by one at this.

The made photocatalyst powder of above inventive embodiments can be carried on the multiple matrix surface.Matrix can be glass, pottery, active carbon or quartz sand etc., and photochemical catalyst can be carried on matrix surface with the form of film.

Claims

1. composite oxides is characterized in that the chemical composition general formula of described composite oxides is: Mg as the application of visible light-responded photochemical catalyst ₄Nb _2-xTa _xO ₉, 0≤x≤2 wherein;

Preparation method's concrete steps of described composite oxides are:

(1) with 99.9% analytically pure chemical raw material MgO, Nb ₂O ₅And Ta ₂O ₅, press Mg ₄Nb _2-xTa _xO ₉Chemical formula weigh batching, wherein 0≤x≤2;

(2) step (1) confected materials is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours mixes levigately, takes out oven dry, 200 mesh sieves;

(3) powder that step (2) is mixed is 1250 ~ 1350 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, by ball mill pulverizing means particle diameter diminished then, is lower than 2 μ m, namely obtains composite oxides Mg ₄Nb _2-xTa _xO ₉Powder.