CN103464143A - Visible light responsive photocatalyst Bi6Ti5WO22 and preparation method thereof - Google Patents

Abstract

The invention discloses a visible light responsive photocatalyst Bi6Ti5WO22 and a preparation method thereof. The chemical composition formula of the photocatalyst is Bi6Ti5WO22. The invention also discloses a preparation method of the material. The preparation method is simple and low in cost; the prepared photocatalyst has excellent catalytic performance, has the function of decomposing harmful chemical substances under visible light irradiation, is good in stability and has good application prospects.

Description

Visible light-responded photochemical catalyst Bi 6ti 5wO 22and preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded photochemical catalyst Bi ₆ti ₅wO ₂₂and 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 bibliographical information bismuthates Bi ₆ti ₅wO ₂₂synthetic, crystal structure and ferroelectric properties.Do not there is visible light-responded photocatalysis performance because ferroelectric is generally insulator, therefore have not yet to see the research report of relevant this compounds photocatalysis performance.We are to Bi recently ₆ti ₅wO ₂₂, Bi ₆zr ₅wO ₂₂and Bi ₆sn ₅wO ₂₂carry out Photocatalytic Performance Study Deng bismuthates, found that Bi ₆ti ₅wO ₂₂there is excellent visible light-responded photocatalysis performance, but Bi ₆zr ₅wO ₂₂and Bi ₆sn ₅wO ₂₂but 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 Bi that has ₆ti ₅wO ₂₂and preparation method thereof.

The chemical constitution formula with visible light-responded bismuthates photochemical catalyst the present invention relates to is: Bi ₆ti ₅wO ₂₂.

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

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, press Bi ₆ti ₅wO ₂₂the 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 1050 ~ 1100 ℃ 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 Bi ₆ti ₅wO ₂₂powder.

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; Bismuthates photochemical catalyst Bi ₆ti ₅wO ₂₂addition 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 Bi ₂o ₃, TiO ₂and WO ₃, press Bi ₆ti ₅wO ₂₂the 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 1050 ℃ 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 bismuthates Bi ₆ti ₅wO ₂₂powder.

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

Embodiment 2:

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, press Bi ₆ti ₅wO ₂₂the 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 1080 ℃ 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 bismuthates Bi ₆ti ₅wO ₂₂powder.

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

Embodiment 3:

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, press Bi ₆ti ₅wO ₂₂the 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 1100 ℃ 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 bismuthates Bi ₆ti ₅wO ₂₂powder.

Prepared photochemical catalyst, be greater than at wavelength under the radiation of visible light of 420nm, and 120min reaches 98.8% 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. a bismuthates, as the application of visible light-responded photochemical catalyst, is characterized in that the chemical constitution formula of described bismuthates is: Bi ₆ti ₅wO ₂₂;

Preparation method's concrete steps of described bismuthates are:

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, press Bi ₆ti ₅wO ₂₂the 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 1050 ~ 1100 ℃ 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 Bi ₆ti ₅wO ₂₂powder.