CN101612562B - Composite oxide photocatalyst Bi4 V(2-x) REx O(11-x) and preparation method thereof - Google Patents

Abstract

The invention discloses a composite oxide photocatalyst Bi4 V(2-x) REx O(11-x) and a preparation method thereof. The chemical compound general formula of the composite oxide photocatalyst is Bi4 V(2-x) REx O(11-x), wherein RE is one of the rare earth elements such as La, Pr, Nd, Sm and Eu, and x is more than 0 and less than or equal to 0.4. The preparation method comprises: 99.9% of analytically pure chemical raw materials of Bi2O3, V2O5 and RE2O3 are weighed and mixed according to the chemical formula of the Bi4 V(2-x) REx O(11-x), wherein the RE is one of the rare earth elements such as La,Pr, Nd, Sm and Eu, and x is more than 0 and less than or equal to 0.4; the prepared raw material is put into a ball-milling jar and added with zirconia ball and absolute ethyl alcohol for ball-milling for 8-10h and fine grinding after being mixed; the obtained product is taken out, dried and filtered through 200-mesh sieve; after that, the evenly mixed powder is presintered at 850-950 DEG C whichis maintained for 4-8h, and then is naturally cooled to be the room temperature; the particle diameter is changed to be smaller by grinding and reaches about 2mu m; finally, the composite oxide photocatalyst Bi4 V(2-x) REx O(11-x) powder is obtained. The invention has simple preparation method, low cost and excellent catalytic performance of the prepared photocatalyst.

Description

Compound oxide photocatalyst Bi 4V 2-xRE xO 11-xAnd preparation method thereof

Technical field

The present invention relates to a kind of visible light responded composite oxide photocatalyst Bi ₄V _2-xRE _xO _11-xAnd preparation method thereof, belong to inorganic field of photocatalytic material.

Background technology

Since 20th century, rapid growth of economy is brought serious negative effect one earth environment problem.Environmental pollution is the problem that countries in the world are extremely paid close attention to, and has caused drinking water source, the industry water source quality of people's lives constantly to descend, and causes atmosphere pollution constantly to aggravate, and causes the continuous destruction of ecological environment, and human existence is constituted a serious threat.In order to address these problems, people control through the whole bag of tricks and curb environmental pollution.Big quantity research shows that nearly all organic pollution can both be the inorganic molecules material by photocatalytic degradation, decolouring, detoxification, mineralising effectively, thereby eliminates pollution and harm to environment.

From phase late 1970s, people proposed to utilize in the photochemical catalyst decomposition water with atmosphere in organic matters such as agricultural chemicals and 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 having absorbed the photon that is higher than its band-gap energy; Hole and electronics have been generated; These holes and electronics carry out oxidation reaction and reduction reaction respectively, reach the purpose of decomposing harmful chemical, organic-biological matter and sterilization.At present; The photochemical catalyst that uses is mainly titanium dioxide, utilized titanium dioxide in the water with atmosphere in organic matters such as agricultural chemicals and odorant decompose, yet the band gap of titanium dioxide is 3.2eV; Only under than the short ultraviolet irradiation of 400nm, just can show activity; Can only almost can not utilize visible light indoor or the local work of uviol lamp is arranged, this has limited the use of titanium dioxide optical catalyst greatly.

Therefore, develop the hot issue that the catalyst that has the high light catalytic activity under a kind of novel visible light has again become photocatalysis field.And in decades recently, a series of niobiums (tantalum) hydrochlorate photochemical catalyst is owing to having higher photocatalytic activity and by broad research.For example, niobate photocatalyst Pb ₃Nb ₄O ₁₃, BiNbO ₄And Bi ₂MNbO ₇(M=Al, Ga, In, Y, rare earth element and Fe) etc. and niobium potassium compound oxide photocatalyst such as KNbO ₃, KNb ₃O ₈, K ₄Nb ₆O ₁₇And K ₆Nb _10.6O ₃₀Deng all having photocatalysis performance preferably.At present, the R and D of bismuth series photocatalyst have obtained a series of great achievements, and bismuthous compound is like BiVO ₄And Bi ₂WO ₄Be reported in and have good absorption under the visible light, and the pentavalent bismuth has equally also caused widely and used.

At present report to have visible light-responded photochemical catalyst kind still very limited, be very necessary so research and develop the new visible light-responded high efficiency photocatalyst that has.

Summary of the invention

The purpose of this invention is to provide a kind of visible light responded composite oxide photocatalyst Bi that has ₄V _2-xRE _xO _11-xAnd preparation method thereof.

A kind of visible light responded composite oxide photocatalyst that has provided by the invention is characterized in that the chemical composition general formula of said compound oxide photocatalyst is: Bi ₄V _2-xRE _xO _11-x, wherein: RE is a kind of among rare-earth elements La, Pr, Nd, Sm and the Eu, 0＜x≤0.4.

Above-mentioned visible light responded composite oxide photocatalyst Bi ₄V _2-xRE _xO _11-xThe preparation method, it is characterized in that, carry out according to the following steps:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And RE ₂O ₃, press Bi ₄V _2-xRE _xO _11-xChemical formula weigh batching, RE are a kind of among rare-earth elements La, Pr, Nd, Sm and the Eu, 0＜x≤0.4;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8-10h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 850-950 ℃ of pre-burning, and insulation 4-8h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain compound oxide photocatalyst Bi ₄V _2-xRE _xO _11-xPowder.

Preparation method of the present invention is simple, cost is low, and the photochemical catalyst of preparation has excellent catalytic performance, under radiation of visible light, has the effect of decomposing harmful chemical, organic-biological matter and sterilization.

The specific embodiment

To specify the present invention below:

1, in order to obtain employed composite oxides among the present invention, at first use solid-phase synthesis to prepare powder, promptly mix various oxides or carbonate according to target composition stoichiometric proportion as raw material, synthetic in air atmosphere under normal pressure again.

2, in order effectively to utilize light, the size of the photochemical catalyst among the present invention is preferably in micron level, or even nano particle, and specific area is bigger.With the oxide powder of solid-phase synthesis preparation, its particle is big and surface area is less, but can particle diameter diminished through pulverizing means such as ball mills.

3, as the simulation organic pollution, its concentration is 20mg/L with methyl orange in photocatalysis experiment of the present invention; The addition of bismuth-system compound oxide photocatalyst is 1g/L; Light source uses the xenon lamp of 300W, and the vessel that reactive tank uses pyrex to process obtain the light of wavelength greater than 420nm long wavelength, irradiates light catalyst then through wave filter; The catalysis time set is 120min.

Embodiment

Serve as that the basis is elaborated to the present invention with concrete practical operation example below.

Embodiment 1:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And La ₂O ₃, press Bi ₄V _1.6La _0.4O _10.6The chemical formula weigh batching;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 950 ℃ of pre-burnings, and insulation 4h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain compound oxide photocatalyst Bi ₄V _1.6La _0.4O _10.6Powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 98.5% to the methyl orange clearance.

Embodiment 2:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And Sm ₂O ₃, press Bi ₄V _1.8Sm _0.2O _10.8The chemical formula weigh batching;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 10h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 900 ℃ of pre-burnings, and insulation 6h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain composite oxides Bi ₄V _1.8Sm _0.2O _10.8Photocatalyst powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 97% to the methyl orange clearance.

Embodiment 3:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And Pr ₂O ₃, press Bi ₄V _1.9Pr _0.1O _10.9The chemical formula weigh batching;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 850 ℃ of pre-burnings, and insulation 8h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain composite oxides Bi ₄V _1.9Pr _0.1O _10.9Photocatalyst powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 98% to the methyl orange clearance.

Embodiment 4:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And Nd ₂O ₃, press Bi ₄V _1.7Nd _0.3O _10.7The chemical formula weigh batching;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 6h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 920 ℃ of pre-burnings, and insulation 10h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain composite oxides Bi ₄V _1.7Nd _0.3O _10.7Photocatalyst powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 98.6% to the methyl orange clearance.

Embodiment 5:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And Eu ₂O ₃, press Bi ₄V _1.98Eu _0.02O _10.98The chemical formula weigh batching;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 870 ℃ of pre-burnings, and insulation 9h, naturally cools to room temperature, pulverizes through ball mill then particle diameter is diminished, and reaches about 2 μ m, can obtain composite oxides Bi ₄V _1.98Eu _0.02O _10.98Photocatalyst powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 99% to the methyl orange clearance.

The present invention never is limited to above embodiment.RE is the compound of two or more elements such as La, Pr, Nd, Sm and Eu; And have and the element of La, Pr, Nd, Sm, Eu analog structure and chemical property such as Y, Ce, Gd, Tb, Dy,, Ho, Tm, Yb and Lu etc. also can make the photochemical catalyst with analogous crystalline structure of the present invention and performance.The bound of each raw material, interval value, and bound, the interval value of technological parameter (like temperature, time, pH value etc.) can both realize the present invention, do not enumerate embodiment one by one at this.

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

Claims (1)

1. composite oxides is characterized in that in Application in Photocatalysis said composite oxides chemical composition general formula is: Bi ₄V _2-xRE _xO _11-x, wherein: RE is a kind of among rare-earth elements La, Pr, Nd, Sm and the Eu, 0＜x≤0.4;

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

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅And RE ₂O ₃, press Bi ₄V _2-xRE _xO _11-xThe chemical formula weigh batching, wherein RE is a kind of among rare-earth elements La, Pr, Nd, Sm and the Eu, 0＜x≤0.4;

2) confected materials is put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8-10h mixes levigately, takes out oven dry, mistake 200 mesh sieves;

3) the above-mentioned powder that mixes is 850-950 ℃ of pre-burning, and insulation 4-8h, naturally cools to room temperature, through ball milling particle diameter diminished then, reaches 2 μ m, can obtain compound oxide photocatalyst Bi ₄V _2-xRE _xO _11-xPowder.