CN104722309B - Visible light-responded photochemical catalyst K2ni2sb8o23and preparation method thereof - Google Patents

Abstract

The invention discloses the visible light responsive photocatalyst K of a kind of high-efficient wide-frequency₂Ni₂Sb₈O₂₃And preparation method thereof.The chemical constitution formula of this photochemical catalyst is K₂Ni₂Sb₈O₂₃.The invention also discloses the preparation method of above-mentioned material.The photochemical catalyst that the present invention obtains has the advantages such as spectral response range width, light conversion efficiency height and good stability, has the effect decomposing harmful chemical, organic-biological matter and sterilization under visible light illumination；Additionally preparation method is simple, synthesis temperature is low, low cost, is suitable for industrial production and application.

Description

Visible light-responded photochemical catalyst K2Ni2Sb8O23And preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded photochemical catalyst K₂Ni₂Sb₈O₂₃And preparation method thereof, belong to inorganic field of photocatalytic material.

Background technology

With socioeconomic development, people increasingly 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 utilize in photochemical catalyst decomposition water and the organic matter such as the 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 be photochemical catalyst after absorbing higher than the photon of its band-gap energy, generate hole and electronics, these holes and electronics carry out oxidation reaction and reduction reaction respectively, reach to decompose the purpose of harmful chemical, organic-biological matter and sterilization.Photochemical catalyst has many kinds, and wherein most representative is titanium dioxide (TiO₂), titanium dioxide has been utilized to decompose the organic matters such as the agricultural chemicals in water and in air and odorant, but the band gap of titanium dioxide is 3.2eV, under the ultraviolet irradiation shorter than 400nm, only just can show activity, can only be at local work that is indoor or that have uviol lamp, being little to utilize visible ray, this greatly limits the use of titanium dioxide optical catalyst.

In view of practicality in decomposing harmful substances for the photochemical catalyst, it is indispensable for utilizing sunlight as light source.The maximum intensity of sunshine medium wavelength visible ray near 500nm to earth's surface for the irradiation, wavelength is that the energy of the visible region of 400nm～750nm is about the 43% of sunshine gross energy, so in order to utilize efficiently, the R and D of bismuth series photocatalyst have been achieved for a series of great achievement, bismuthous compound such as BiVO₄、Bi₂MoO₆、Bi₂Mo₂O₉、Bi₂Mo₃O₁₂And Bi₂WO₄It is in the news and there is good absorption under visible light.A series of niobiums (tantalum) hydrochlorate photochemical catalyst is widely studied owing to having higher photocatalytic activity.For example, niobate photocatalyst Pb₃Nb₄O₁₃、BiNbO₄And Bi₂MNbO₇(M=Al, Ga, In, Y, rare earth element and Fe) etc. and niobium potassium compound oxide photocatalyst such as KNbO₃、KNb₃O₈、K₄Nb₆O₁₇And K₆Nb_10.6O₃₀Deng all having preferable photocatalysis performance, but in visible-range, its intrinsic photocatalytic effect is very weak or does not has activity.

Although photocatalysis research has been carried out the several years, major part of exploring and develop to visible light-responded photochemical catalyst is the summary of experience being drawn by great many of experiments at present, in theory also cannot be from the crystal structure of compound, composition, its photocatalysis performance is predicted in the physicochemical properties such as molecular weight, therefore at present report to have visible light-responded photochemical catalyst species still very limited, and it is low to there is light conversion efficiency, synthesis difficulty, poor stability and the problem such as spectral response range is narrow, research and develop that new preparation method is simple and to have the visible light-responded high efficiency photocatalyst of wideband be that this area scientific and technical personnel thirst for solving always but are difficult to the difficult problem succeeding all the time, which greatly limits extensively application and the development of photochemical catalyst.We are to consisting of K₂Ni₂Sb₈O₂₃、Li₂Ni₂Sb₈O₂₃And K₂Zn₂Sb₈O₂₃Sample carried out Photocatalytic Performance Study.It is found that K₂Ni₂Sb₈O₂₃Band gap width is 2.49eV, has excellent visible light-responded photocatalysis performance；Li₂Ni₂Sb₈O₂₃And K₂Zn₂Sb₈O₂₃For insulator, under ultraviolet irradiation, do not show activity yet.

Content of the invention

It is an object of the invention to provide and a kind of there is visible light-responded photochemical catalyst K₂Ni₂Sb₈O₂₃And preparation method thereof.

The chemical constitution formula with visible light-responded photochemical catalyst that the present invention relates to is: K₂Ni₂Sb₈O₂₃。

The preparation method of above-mentioned visible light-responded photochemical catalyst concretely comprises the following steps:

(1) by 99.9% analytically pure chemical raw material K₂CO₃, NiO and Sb₂O₅Starting powder press K₂Ni₂Sb₈O₂₃Composition weigh dispensing.

(2) the raw material mixing preparing step (1), puts in ball grinder, adds zirconia ball and absolute ethyl alcohol, ball milling 8 hours, be mixed and finely ground, take out and dry, cross 200 mesh sieves.

(3) powder mixing step (2) is 950～1000 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, and then being pulverized by ball mill makes average diameter of particles diminish, and is less than 2 μm, i.e. obtains K₂Ni₂Sb₈O₂₃Powder.

Advantages of the present invention: K₂Ni₂Sb₈O₂₃The visible light-responded wide frequency range of photochemical catalyst, light conversion efficiency height and good stability, there is effect under visible light illumination that decompose harmful chemical, organic-biological matter and sterilization；Additionally preparation method is simple, synthesis temperature is low, low cost, is suitable for industrial production and application.

Detailed description of the invention

Present invention will be described in detail below:

1st, in order to obtain the composite oxides used in the present invention, prepare powder first by solid-phase synthesis, i.e. various oxide or carbonate as raw material are mixed according to target constitutional chemistry metering ratio, then synthesize in air atmosphere at ambient pressure.

2 in order to effectively utilize light, the size of the photochemical catalyst in the present invention preferably in micron level, even nano particle, and specific surface area is bigger.The oxide powder prepared by solid-phase synthesis, its particle is relatively big and surface area is less, but can be by ball mill pulverizing means and make particle diameter diminish.

3rd, the photocatalysis experiment of the present invention is using methyl orange as simulation organic pollution, and its concentration is 20mg/L；Photochemical catalyst K₂Ni₂Sb₈O₂₃Addition be 1g/L；Light source uses the xenon lamp of 300W, and reactive tank uses the vessel that pyrex is made, and obtains the light more than 420nm for the wavelength by wave filter, then irradiates photochemical catalyst；Catalysis time is set as 60 minutes.

Embodiment 1:

(1) by 99.9% analytically pure chemical raw material K₂CO₃, NiO and Sb₂O₅Starting powder press K₂Ni₂Sb₈O₂₃Composition weigh dispensing.

(2) the raw material mixing preparing step (1), puts in ball grinder, adds zirconia ball and absolute ethyl alcohol, ball milling 8 hours, be mixed and finely ground, take out and dry, cross 200 mesh sieves.

(3) powder mixing step (2) is 950 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, and then being pulverized by ball mill makes average diameter of particles diminish, and is less than 2 μm, i.e. obtains K₂Ni₂Sb₈O₂₃Powder.

Prepared photochemical catalyst, under the radiation of visible light more than 420nm for the wavelength, reaches 97.2% to methyl orange clearance in 60 minutes.

Embodiment 2:

(1) by 99.9% analytically pure chemical raw material K₂CO₃, NiO and Sb₂O₅Starting powder press K₂Ni₂Sb₈O₂₃Composition weigh dispensing.

(2) the raw material mixing preparing step (1), puts in ball grinder, adds zirconia ball and absolute ethyl alcohol, ball milling 8 hours, be mixed and finely ground, take out and dry, cross 200 mesh sieves.

(3) powder mixing step (2) is 980 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, and then being pulverized by ball mill makes average diameter of particles diminish, and is less than 2 μm, i.e. obtains K₂Ni₂Sb₈O₂₃Powder.

Prepared photochemical catalyst, under the radiation of visible light more than 420nm for the wavelength, reaches 98.7% to methyl orange clearance in 60 minutes.

Embodiment 3:

(1) by 99.9% analytically pure chemical raw material K₂CO₃, NiO and Sb₂O₅Starting powder press K₂Ni₂Sb₈O₂₃Composition weigh dispensing.

(2) the raw material mixing preparing step (1), puts in ball grinder, adds zirconia ball and absolute ethyl alcohol, ball milling 8 hours, be mixed and finely ground, take out and dry, cross 200 mesh sieves.

(3) powder mixing step (2) is 1000 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, and then being pulverized by ball mill makes average diameter of particles diminish, and is less than 2 μm, i.e. obtains K₂Ni₂Sb₈O₂₃Powder.

Prepared photochemical catalyst, under the radiation of visible light more than 420nm for the wavelength, 60min reaches 98.2% to methyl orange clearance.

The present invention is never limited to above example.The bound of each temperature, interval value can realize the present invention, embodiment numerous to list herein.

The made photocatalyst powder of above inventive embodiments can be carried on multiple matrix surface.Matrix can be glass, pottery, activated carbon or quartz sand etc., and photochemical catalyst can be carried on matrix surface in the form of a film.

Claims (1)

1. a visible light-responded photochemical catalyst, it is characterised in that the chemical constitution formula of described photochemical catalyst is K₂Ni₂Sb₈O₂₃；

The preparation method of described photochemical catalyst concretely comprises the following steps:

(1) by 99.9% analytically pure chemical raw material K₂CO₃, NiO and Sb₂O₅Starting powder press K₂Ni₂Sb₈O₂₃Composition weigh dispensing；

(2) the raw material mixing preparing step (1), puts in ball grinder, adds zirconia ball and absolute ethyl alcohol, ball milling 8 hours, be mixed and finely ground, take out and dry, cross 200 mesh sieves；

(3) powder mixing step (2) is 950 ~ 1000 DEG C of pre-burnings, and is incubated 6 hours, naturally cools to room temperature, and then being pulverized by ball mill makes average diameter of particles be less than 2 μm, i.e. obtains K₂Ni₂Sb₈O₂₃Powder.