CN103480363A - Visible-light-responsive photocatalyst SrLa6W10O40 and preparation method thereof - Google Patents

Abstract

The invention discloses a visible-light-responsive photocatalyst SrLa6W10O40 and a preparation method thereof. The chemical formula of the photocatalyst is SrLa6W10O40. The invention also discloses a preparation method of the material. The preparation method disclosed by the invention is simple and low in cost; and the prepared photocatalyst has the advantages of excellent catalytic property and high stability, has the function of decomposing harmful chemical substances under visible light irradiation, and thus, has favorable application prospects.

Description

Visible light-responded photochemical catalyst SrLa 6w 10o 40and preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded photochemical catalyst SrLa ₆w ₁₀o ₄₀and 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.

From phase late 1970s, people proposed to utilize in the photochemical catalyst decomposition water and atmosphere in agricultural chemicals and the organic matter such as odorant, and application examples such as self-cleaning that scribble the surface of solids of photochemical catalyst.The principle of light-catalyzed reaction is that photochemical catalyst is after the photon absorbed higher than its band-gap energy, hole and electronics have been generated, these holes and electronics carry out respectively oxidation reaction and reduction reaction, reach the purpose of decomposing harmful chemical, organic-biological matter and sterilization.Photochemical catalyst has many kinds, and wherein most representative is titanium dioxide (TiO ₂), utilized titanium dioxide in water and the agricultural chemicals in atmosphere and the organic matters such as odorant decomposed, yet the band gap of titanium dioxide is 3.2eV, only under the ultraviolet irradiation shorter than 400nm, just can show activity, can only be indoor or the local work of uviol lamp arranged, almost can not utilize visible ray, this has limited the use of titanium dioxide optical catalyst greatly.

Consider the practicality of photochemical catalyst in decomposing harmful substances, utilizing sunshine is indispensable as light source.Irradiation is near sunshine medium wavelength visible light intensity maximum 500nm on earth's surface, the energy of the visible region that wavelength is 400nm ~ 750nm is approximately 43% of sunshine gross energy, so for efficient utilization, the R and D of bismuth series photocatalyst have obtained a series of great achievements, and bismuthous compound is as BiVO ₄, Bi ₂moO ₆, Bi ₂mo ₂o ₉, Bi ₂mo ₃o ₁₂and Bi ₂wO ₄be reported under visible ray and there is good absorption.A series of niobiums (tantalum) hydrochlorate photochemical catalyst is widely studied owing to having higher photocatalytic activity.For example, niobate photocatalyst Pb ₃nb ₄o ₁₃, BiNbO ₄and Bi ₂mNbO ₇(M=Al, Ga, In, Y, rare earth element or Fe) etc. with niobium potassium compound oxide photocatalyst as KNbO ₃, KNb ₃o ₈, K ₄nb ₆o ₁₇and K ₆nb _10.6o ₃₀deng all thering is photocatalysis performance preferably.

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, still exist that light conversion efficiency is low, poor stability and the problem such as the spectrum respective range is narrow, so research and develop the new visible light-responded high efficiency photocatalyst that has, be very necessary.Existing document [A.A. Evdokimov and V.K. Trunov, Russ. J. Inore. Chem. (Engl. Transl.), 18, 1506, (1973); Feng fruit, preparation and the luminescent properties research of red fluorescence powders for six kinds of New LEDs., academic dissertation, the academic classical collection of Xiamen University storehouse] and reported respectively compound S rLa ₆w ₁₀o ₄₀crystal structure and as the application of the luminescent material of near ultraviolet excitation, but do not relate to relevant photocatalysis performance and application thereof.In order to explore the new visible light-responded high efficiency photocatalyst that has, we are to SrLa ₆w ₁₀o ₄₀, BaLa ₆w ₁₀o ₄₀and CaLa ₆w ₁₀o ₄₀carry out Photocatalytic Performance Study Deng composite oxides, found that SrLa ₆w ₁₀o ₄₀there is excellent visible light-responded photocatalysis performance, but BaLa ₆w ₁₀o ₄₀and CaLa ₆w ₁₀o ₄₀but do not there is visible light-responded photocatalysis performance.

Summary of the invention

The purpose of this invention is to provide a kind of visible light-responded photochemical catalyst SrLa that has ₆w ₁₀o ₄₀and preparation method thereof.

The chemical constitution formula with visible light-responded photochemical catalyst the present invention relates to is: SrLa ₆w ₁₀o ₄₀.

Preparation method's concrete steps of above-mentioned visible light-responded photochemical catalyst are:

(1) by 99.9% analytically pure chemical raw material SrCO ₃, La ₂o ₃and WO ₆, press SrLa ₆w ₁₀o ₄₀the chemical formula weigh batching.

(2) raw material step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours, be mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed is 1000 ~ 1040 ℃ 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, obtains SrLa ₆w ₁₀o ₄₀powder.

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

Below will be specifically described the present invention:

1, the composite oxides in order to obtain using in the present invention, at first used solid-phase synthesis to prepare powder, the various oxides as raw material or carbonate measured than being mixed according to the target constitutional chemistry, more synthetic 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.The oxide powder prepared with solid-phase synthesis, its particle is large and surface area is less, but can particle diameter be diminished by ball mill pulverizing means.

3, photocatalysis experiment of the present invention is usingd methyl orange as the simulation organic pollution, and its concentration is 20mg/L; Photochemical catalyst SrLa ₆w ₁₀o ₄₀addition be 1g/L; Light source is used the xenon lamp of 300W, and the vessel that reactive tank is used pyrex to make, obtain by wave filter the light that wavelength is greater than 420nm long wavelength, then irradiates photochemical catalyst; Catalysis time is set as 120 minutes.

Embodiment 1:

(1) by 99.9% analytically pure chemical raw material SrCO ₃, La ₂o ₃and WO ₆, press SrLa ₆w ₁₀o ₄₀the chemical formula weigh batching.

(2) raw material step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours, be mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed is 1000 ℃ 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, obtains SrLa ₆w ₁₀o ₄₀powder.

Prepared photochemical catalyst, be greater than at wavelength under the radiation of visible light of 420nm, the methyl orange clearance reached to 99% in 120 minutes.

Embodiment 2:

(1) by 99.9% analytically pure chemical raw material SrCO ₃, La ₂o ₃and WO ₆, press SrLa ₆w ₁₀o ₄₀the chemical formula weigh batching.

(2) raw material step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours, be mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed is 1020 ℃ 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, obtains SrLa ₆w ₁₀o ₄₀powder.

Prepared photochemical catalyst, be greater than at wavelength under the radiation of visible light of 420nm, the methyl orange clearance reached to 99.4% in 120 minutes.

Embodiment 3:

(1) by 99.9% analytically pure chemical raw material SrCO ₃, La ₂o ₃and WO ₆, press SrLa ₆w ₁₀o ₄₀the chemical formula weigh batching.

(2) raw material step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours, be mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed is 1040 ℃ 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, obtains SrLa ₆w ₁₀o ₄₀powder.

Prepared photochemical catalyst, be greater than at wavelength under the radiation of visible light of 420nm, and 120min reaches 99.1% to the methyl orange clearance.

The present invention never is limited to above embodiment.The bound of each temperature, interval value can realize the present invention, at this, do not enumerate embodiment.

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)

1. composite oxides, as the application of visible light-responded photochemical catalyst, is characterized in that the chemical constitution formula of described composite oxides is: SrLa ₆w ₁₀o ₄₀;

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

(1) by 99.9% analytically pure chemical raw material SrCO ₃, La ₂o ₃and WO ₆, press SrLa ₆w ₁₀o ₄₀the chemical formula weigh batching;

(2) raw material step (1) prepared mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8 hours, be mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves;

(3) powder step (2) mixed is 1000 ~ 1040 ℃ 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, obtains SrLa ₆w ₁₀o ₄₀powder.