CN103464143B - 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 be realize sustainable development, improve people's living standard and safeguard national security in the urgent need to.

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

Consider the practicality of photochemical catalyst in decomposing harmful substances, utilize sunshine to be indispensable as light source.Irradiate maximum to sunshine medium wavelength intensity of visible ray near 500nm on earth's surface, wavelength is the energy of the visible region of 400nm ~ 750nm is approximately 43% of sunshine gross energy, so in order to efficient utilization, the R and D of bismuth series photocatalyst have achieved a series of great achievement, and bismuthous compound is as BiVO ₄, Bi ₂moO ₆, Bi ₂mo ₂o ₉, Bi ₂mo ₃o ₁₂and Bi ₂wO ₄be in the news and there is good absorption under visible light.A series of niobium (tantalum) hydrochlorate photochemical catalyst is widely studied owing to having higher photocatalytic activity.Such as, 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 there is good photocatalysis performance.

Although photocatalysis research has carried out the several years, but at present report to have visible light-responded photochemical catalyst kind still very limited, still also exist that light conversion efficiency is low, poor stability and the problem such as spectrum respective range is narrow, so it is very necessary for researching and developing the new visible light-responded high efficiency photocatalyst that has.Have bibliographical information bismuthates Bi ₆ti ₅wO ₂₂synthesis, crystal structure and ferroelectric properties.Do not have visible light-responded photocatalysis performance because ferroelectric is generally insulator, the research therefore had not yet to see about this compounds photocatalysis performance is reported.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 not there is visible light-responded photocatalysis performance.

Summary of the invention

The object of this invention is to provide and a kind of there is visible light-responded photochemical catalyst Bi ₆ti ₅wO ₂₂and preparation method thereof.

The chemical constitution formula with visible light-responded bismuthate photocatalyst that the present invention relates to is: Bi ₆ti ₅wO ₂₂.

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

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, by Bi ₆ti ₅wO ₂₂chemical formula weigh batching.

(2) raw material mixing step (1) prepared, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours, is mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed 1050 ~ 1100 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then pulverizes means by ball mill and particle diameter is diminished, lower than 2 μm, namely obtain Bi ₆ti ₅wO ₂₂powder.

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 visible light illumination.

Detailed description of the invention

To be specifically described the present invention below:

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

2, in order to effectively 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 oxide powder prepared by solid-phase synthesis, its particle is comparatively large and surface area is less, but can pulverize means by ball mill makes particle diameter diminish.

3, photocatalysis experiment of the present invention is using methyl orange as simulation organic pollution, and its concentration is 20mg/L; Bismuthate photocatalyst Bi ₆ti ₅wO ₂₂addition be 1g/L; Light source uses the xenon lamp of 300W, the vessel that reactive tank uses pyrex to make, and obtains the light that wavelength is greater than 420nm long wavelength, then irradiate photochemical catalyst by wave filter; 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, by Bi ₆ti ₅wO ₂₂chemical formula weigh batching.

(2) raw material mixing step (1) prepared, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours, is mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed 1050 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then pulverizes means by ball mill and particle diameter is diminished, lower than 2 μm, namely obtain bismuthates Bi ₆ti ₅wO ₂₂powder.

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

Embodiment 2:

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, by Bi ₆ti ₅wO ₂₂chemical formula weigh batching.

(2) raw material mixing step (1) prepared, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours, is mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed 1080 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then pulverizes means by ball mill and particle diameter is diminished, lower than 2 μm, namely obtain bismuthates Bi ₆ti ₅wO ₂₂powder.

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

Embodiment 3:

(1) by 99.9% analytically pure chemical raw material Bi ₂o ₃, TiO ₂and WO ₃, by Bi ₆ti ₅wO ₂₂chemical formula weigh batching.

(2) raw material mixing step (1) prepared, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours, is mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves.

(3) powder step (2) mixed 1100 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then pulverizes means by ball mill and particle diameter is diminished, lower than 2 μm, namely obtain bismuthates Bi ₆ti ₅wO ₂₂powder.

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

The present invention is never limited to above embodiment.Bound, the interval value of each temperature 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 in the form of a film.

Claims (1)

1. bismuthates is as an application for visible light-responded photochemical catalyst, it 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, by Bi ₆ti ₅wO ₂₂chemical formula weigh batching;

(2) raw material mixing step (1) prepared, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8 hours, is mixed and finely ground, and takes out and dries, and crosses 200 mesh sieves;

(3) powder step (2) mixed 1050 ~ 1100 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, then pulverizes means by ball mill and particle diameter is diminished, lower than 2 μm, namely obtain Bi ₆ti ₅wO ₂₂powder.