CN103170323A

CN103170323A - Titanate photocatalyst A2TiO4 and preparation method thereof

Info

Publication number: CN103170323A
Application number: CN2013101302165A
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: 2013-04-16
Filing date: 2013-04-16
Publication date: 2013-06-26
Anticipated expiration: 2033-04-16
Also published as: CN103170323B

Abstract

The invention discloses a titanate photocatalyst A2TiO4 with visible-light response and a preparation method thereof. The chemical constitution formula of the titanate photocatalyst is A2TiO4, wherein A is one or two of Ca and Sr. A preparation method of the material is also disclosed by the invention. The titanate photocatalyst A2TiO4 disclosed by the invention is simple in preparation method and low in cost; the prepared photocatalyst has excellent catalytic performance, has the effect of decomposing harmful chemical substances under irradiation of a visible light, and has good stability and good application prospect.

Description

Titanate photochemical catalyst A 2TiO 4And preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded titanate photochemical catalyst A ₂TiO ₄And preparation method thereof, belong to inorganic field of photocatalytic material.

Background technology

Along with socioeconomic development, people more and more pay close attention to for the energy and ecological environment, solve energy shortage and problem of environmental pollution and be realize sustainable development, improve people's living standard and safeguard national security in the urgent need to.

Fujishima had found TiO in 1972 ₂Semi-conducting electrode has the effect of photodissociation water under UV-irradiation, caused thus the research boom of conductor photocatalysis.Its major domain comprises: (1) impels the organic pollution in water and air thoroughly to resolve into CO take solar energy as the energy take airborne oxygen as oxidant ₂, H ₂O and other inorganic salts are a kind of desirable Pollutant Control Technologys; (2) utilizing solar energy that water decomposition is the chemical energy such as hydrogen and oxygen, is the important component part of hydrogen economy; (3) directly change solar energy into electric energy.Although TiO ₂A kind of extremely outstanding photochemical catalyst, but due to TiO ₂Energy gap large (3. 2eV), the ultraviolet light that only has 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 earth's surface concentrates on 460 ~ 500nm, ultraviolet composition (300 ~ 400nm) less thaies 5%, therefore how to utilize efficiently sunshine to carry out light-catalyzed reaction, exploitation can be caused just day by day by the photochemical catalyst of excited by visible light people's interest.

To take full advantage of sunshine, people have carried out many study on the modification to it for the response wave length scope of expanding TiO2, comprise metal ion mixing, nonmetallic ion-doped, surface sensitization, coupling semiconductor and introduce the methods such as oxygen room, Implantation.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 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, Ta), Stibotantalite Wolframite structural type compd B iMO ₄The KNbO of (M=Nb, 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.The researcher is also to some titanates such as SrTiO both at home and abroad ₃, Bi ₄Ti ₃O ₁₂Deng having carried out photocatalysis characteristic research.

Although 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, poor stability and the problem such as the spectrum respective range is narrow, be very necessary so research and develop the new visible light-responded high efficiency photocatalyst that has.Document [P. L. Wise, I.M. Reaney, W. E. Lee, T. J. Price, D.M. Iddles, D.S. Cannell, Structure-microwave property relations of Ca and Sr titanates, Journal of the European Ceramic Society, 2001,21:2629 – 2632] reported titanate A ₂TiO ₄Crystal structure and the microwave dielectric property of (A=Ca or Sr).Consider the research report that there is no at present relevant this compounds photocatalysis performance, its crystal structure and SrTiO ₃, Bi ₄Ti ₃O ₁₂Deng also not identical, we are to titanate A ₂TiO ₄(A=Ca or Sr) carried out Photocatalytic Performance Study, found that this compounds has excellent visible light-responded photocatalysis performance.

Summary of the invention

The purpose of this invention is to provide a kind of visible light-responded titanate photochemical catalyst A that has ₂TiO ₄And preparation method thereof.

The chemical composition general formula with visible light-responded titanate that the present invention relates to is: A ₂TiO ₄, wherein A is one or both in Ca and Sr;

Preparation method's concrete steps of described titanate are:

(1) with 99.9% analytically pure chemical raw material ACO ₃And TiO ₂, press A ₂TiO ₄The chemical formula weigh batching, wherein A is one or both in Ca and Sr.

(2) raw material that step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours mixes levigately, takes out oven dry, mistake 200 mesh sieves.

(3) powder that step (2) is mixed is 1200 ~ 1250 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then by pulverizing means such as ball mills, particle diameter diminished, and lower than 2 μ m, namely obtains titanate A ₂TiO ₄Powder.

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

The specific embodiment

The below will be specifically described the present invention:

1, at first the composite oxides in order to obtain using in the present invention use solid-phase synthesis to prepare powder, namely as the various oxides of raw material or carbonate according to the metering of target constitutional chemistry than mixing, then synthesize in air atmosphere under normal pressure.

2, in order effectively to utilize light, the size of the photochemical catalyst in the present invention is preferably in micron level, or even nano particle, and specific area is larger.With the oxide powder of solid-phase synthesis preparation, its particle is large 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; Titanate photochemical catalyst A ₂TiO ₄Addition 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 shine photochemical catalyst; Catalysis time is set as 120 minutes.

Embodiment 1:

(1) with 99.9% analytically pure chemical raw material CaCO ₃And TiO ₂, press Ca ₂TiO ₄The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1200 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then by ball mill pulverizing means, particle diameter diminished, and lower than 2 μ m, namely obtains titanate Ca ₂TiO ₄Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.2% to the methyl orange clearance in 120 minutes.

Embodiment 2:

(1) with 99.9% analytically pure chemical raw material CaCO ₃, SrCO ₃And TiO ₂, press CaSrTiO ₄The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1230 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then by ball mill pulverizing means, particle diameter diminished, and lower than 2 μ m, namely obtains titanate CaSrTiO ₄Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.8% to the methyl orange clearance in 120 minutes.

Embodiment 3:

(1) with 99.9% analytically pure chemical raw material SrCO ₃And TiO ₂, press Sr ₂TiO ₄The 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, then by ball mill pulverizing means, particle diameter diminished, and lower than 2 μ m, namely obtains titanate Sr ₂TiO ₄Powder.

Prepared photochemical catalyst under the radiation of visible light of wavelength greater than 420nm, reached 98.4% to the methyl orange clearance in 120 minutes.

Embodiment 4:

(1) with 99.9% analytically pure chemical raw material CaCO ₃, SrCO ₃And TiO ₂, press Ca _0.4Sr _1.6TiO ₄The chemical formula weigh batching.

(3) powder that step (2) is mixed is 1220 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then by ball mill pulverizing means, particle diameter diminished, and lower than 2 μ m, namely obtains titanate Ca _0.4Sr _1.6TiO ₄Powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 99.2% to the methyl orange clearance.

The present invention never is limited to above embodiment.Have element such as Sn with Ti analog structure and chemical property, Zr etc., and also can make photochemical catalyst with analogous crystalline structure of the present invention and performance with the element of Ca and Sr analog structure and chemical property such as Ba, Pb.The bound of each temperature, interval value can realize the present invention, do not enumerate embodiment at this.

The made photocatalyst powder of above inventive embodiments can be carried on 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. a titanate as the application of visible light-responded photochemical catalyst, is characterized in that the chemical composition general formula of described titanate is: A ₂TiO ₄, wherein A is one or both in Ca and Sr;

Preparation method's concrete steps of described titanate are:

(1) with 99.9% analytically pure chemical raw material ACO ₃And TiO ₂, press A ₂TiO ₄The chemical formula weigh batching, wherein A is one or both in Ca and Sr;

(2) raw material that step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours mixes levigately, takes out oven dry, mistake 200 mesh sieves;

(3) powder that step (2) is mixed is 1200 ~ 1250 ℃ of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then by ball mill pulverizing means, particle diameter diminished, and lower than 2 μ m, namely obtains titanate A ₂TiO ₄Powder.