CN103433029A - Visible light response photocatalyst Ba9Nb2W4O26 and preparation method thereof - Google Patents

Abstract

The invention discloses a visible-light response composite oxide photocatalyst Ba9Nb2W4O26 and a preparation method thereof. The chemical composition formula of the composite oxide photocatalyst is Ba9Nb2W4O26. The invention also discloses a preparation method of the photocatalyst. The preparation method is simple and low in cost; the prepared photocatalyst has excellent catalytic performance, has an effect of decomposing harmful chemical substances in visible-light radiation, is good in stability, and has an excellent application prospect.

Description

Visible light-responded photocatalyst Ba 9nb 2w 4o 26and preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded photocatalyst Ba ₉nb ₂w ₄o ₂₆and 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.In addition, 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 [J. Bezjak, B. Jan ar, P. Boullay, A. Re nik, D. Suvorov, J. Am. Ceram. Soc., 2009,92 (12): 3022-3032.] has been reported niobates composite oxides Ba ₉nb ₂w ₄o ₂₆preparation and microwave dielectric property, but have not yet to see the research report of relevant this compounds photocatalysis performance, we are to Ba ₉nb ₂w ₄o ₂₆, Ba ₉ta ₂w ₄o ₂₆, Sr ₉nb ₂w ₄o ₂₆, Ca ₉nb ₂w ₄o ₂₆carry out Photocatalytic Performance Study, found that Ba ₉nb ₂w ₄o ₂₆there is excellent visible light-responded photocatalysis performance, but the compound of other composition do not have visible light-responded photocatalysis performance.

Summary of the invention

The purpose of this invention is to provide a kind of visible light-responded photocatalyst Ba that has ₉nb ₂w ₄o ₂₆and preparation method thereof.

The chemical constitution formula with visible light-responded compound oxide photocatalyst the present invention relates to is: Ba ₉nb ₂w ₄o ₂₆.

Preparation method's concrete steps of above-mentioned visible light-responded compound oxide photocatalyst are:

(1) by 99.9% analytically pure chemical raw material BaCO ₃, Nb ₂o ₅and WO ₃, press Ba ₉nb ₂w ₄o ₂₆the 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 1150 ~ 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, obtains composite oxides Ba ₉nb ₂w ₄o ₂₆powder.

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; Composite oxide photocatalyst Ba ₉nb ₂w ₄o ₂₆addition 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 BaCO ₃, Nb ₂o ₅and WO ₃, press Ba ₉nb ₂w ₄o ₂₆the 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 1150 ℃ 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 composite oxides Ba ₉nb ₂w ₄o ₂₆powder.

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

Embodiment 2:

(1) by 99.9% analytically pure chemical raw material BaCO ₃, Nb ₂o ₅and WO ₃, press Ba ₉nb ₂w ₄o ₂₆the 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 1175 ℃ 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 composite oxides Ba ₉nb ₂w ₄o ₂₆powder.

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

Embodiment 3:

(1) by 99.9% analytically pure chemical raw material BaCO ₃, Nb ₂o ₅and WO ₃, press Ba ₉nb ₂w ₄o ₂₆the 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 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, obtains composite oxides Ba ₉nb ₂w ₄o ₂₆powder.

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: Ba ₉nb ₂w ₄o ₂₆;

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

(1) by 99.9% analytically pure chemical raw material BaCO ₃, Nb ₂o ₅and WO ₃, press Ba ₉nb ₂w ₄o ₂₆the 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 1150 ~ 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, obtains composite oxides Ba ₉nb ₂w ₄o ₂₆powder.