CN101612561A - Visible light-responded bismuth-system compound oxide photocatalyst and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of visible light-responded bismuth-system compound oxide photocatalyst and preparation method thereof.The visible light-responded bismuth-system compound oxide photocatalyst that the present invention relates to, its chemical composition general formula is Bi ₄M ₂O ₁₁, wherein the M element is one or both among Nb, Ta and the V.The preparation method is: with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅, Nb ₂O ₅And Ta ₂O ₅, press Bi ₄M ₂O ₁₁The chemical formula weigh batching, wherein the M element is one or more among Nb, Ta and the V; The chemical raw material that configures is mixed, and ball milling 8-10h takes out oven dry, crosses 200 mesh sieves; The above-mentioned powder that mixes is 800-950 ℃ of pre-burning, and insulation 4-8h, naturally cools to room temperature, by ball milling particle diameter is diminished, and reaches about 2 μ m.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 radiation of visible light.

Description

Visible light-responded bismuth-system compound oxide photocatalyst and preparation method thereof

Technical field

The present invention relates to a kind of visible light-responded bismuth-system compound oxide photocatalyst and preparation method thereof.

Background technology

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 by the whole bag of tricks and curb environmental pollution.

From phase late 1970s, people proposed to utilize in the photochemical catalyst decomposition water and atmosphere in agricultural chemicals and 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 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 and the agricultural chemicals in the atmosphere and organic matters such as 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.

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 the face of land, wavelength is that the energy of the visible region of 400nm-750nm approximately is 43% of a sunshine gross energy, so in order to utilize solar spectrum efficiently, searching has the attention that visible light-responded photochemical catalyst has caused people.The R and D of bismuth series photocatalyst have obtained a series of great achievements, and bismuthous compound is reported in as BiVO4 and Bi2WO4 and has good absorption under the visible light, and the pentavalent bismuth has equally also caused widely and uses.

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 have visible light-responded bismuth-system compound oxide photocatalyst with and preparation method thereof.

The visible light-responded bismuth-system compound oxide photocatalyst that the present invention relates to, its chemical composition general formula is Bi ₄M ₂O ₁₁, wherein the M element is one or both among Nb, Ta and the V.

The preparation method of above-mentioned visible light-responded bismuth-system compound oxide photocatalyst is characterized in that, carries out according to the following steps:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅, Nb ₂O ₅And Ta ₂O ₅, press Bi ₄M ₂O ₁₁The chemical formula weigh batching, wherein the M element is one or both among Nb, Ta and the V;

The above-mentioned chemical raw material that 2) will configure mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8-10h mixes levigately, takes out oven dry, 200 mesh sieves;

3) the above-mentioned powder that mixes is 800-950 ℃ of pre-burning, and insulation 4-8h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide photocatalyst Bi ₄M ₂O ₁₁Powder.

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 radiation of visible light.

The specific embodiment

To be specifically described 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 various oxides or carbonate as raw material are mixed burning in air atmosphere, synthetic under normal pressure again according to target composition stoichiometric proportion.If the raw material of easy volatilization is then eliminated the influence of volatility of raw material to reaction by the ratio of excessive this raw material.

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 be diminished by 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 make obtain the light of wavelength greater than 420nm long wavelength, irradiates light catalyst then by wave filter; The catalysis time set is 120min.

Embodiment 1:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃And V ₂O ₅, press Bi ₄V ₂O ₁₁The chemical formula weigh batching.

2) chemical raw material for preparing is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, 200 mesh sieves.

3) the above-mentioned powder that mixes is 800 ℃ of pre-burnings, and insulation 8h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide Bi ₄V ₂O ₁₁Photocatalyst powder.

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 ₃And Nb ₂O ₅, press Bi ₄Nb ₂O ₁₁The chemical formula weigh batching.

2) chemical raw material for preparing is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 10h mixes levigately, takes out oven dry, 200 mesh sieves.

3) the above-mentioned powder that mixes is 850 ℃ of pre-burnings, and insulation 4h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide Bi ₄V ₂O ₁₁Photocatalyst 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 Nb ₂O ₅, press Bi ₄V _0.4Nb _1.6O ₁₁The chemical formula weigh batching.

2) chemical raw material for preparing is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, 200 mesh sieves.

3) the above-mentioned powder that mixes is 830 ℃ of pre-burnings, and insulation 6h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide Bi ₄V _0.4Nb _1.6O ₁₁Photocatalyst 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 Ta ₂O ₅, press Bi ₄V _1.2Ta _0.8O ₁₁The chemical formula weigh batching.

2) chemical raw material for preparing is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 9h mixes levigately, takes out oven dry, 200 mesh sieves.

3) the above-mentioned powder that mixes is 870 ℃ of pre-burnings, and insulation 6h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide Bi ₄V _1.2Ta _0.8O ₁₁Photocatalyst powder.

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

Embodiment 5:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, Nb ₂O ₅And Ta ₂O ₅, press Bi ₄Nb _0.9Ta _1.1O ₁₁The chemical formula weigh batching.

2) chemical raw material for preparing is mixed, put into ball grinder, add zirconia ball and absolute ethyl alcohol, ball milling 8h mixes levigately, takes out oven dry, 200 mesh sieves.

3) the above-mentioned powder that mixes is 950 ℃ of pre-burnings, and insulation 4h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide Bi ₄Nb _0.9Ta _1.1O ₁₁Photocatalyst powder.

Prepared photochemical catalyst, under the radiation of visible light of wavelength greater than 420nm, 120min reaches 95% to the methyl orange clearance.

The bound of each raw material of the present invention, interval value, and bound, the interval value of technological parameter (as temperature, time, pH value etc.) can both realize the present invention, do not enumerate embodiment one by one at this.

Claims (2)

1. visible light-responded bismuth-system compound oxide photocatalyst, it is characterized in that: its chemical composition general formula is Bi ₄M ₂O ₁₁, wherein the M element is one or both among Nb, Ta and the V.

2. the preparation method of visible light-responded bismuth-system compound oxide photocatalyst as claimed in claim 1 is characterized in that concrete steps are:

1) with 99.9% analytically pure chemical raw material Bi ₂O ₃, V ₂O ₅, Nb ₂O ₅And Ta ₂O ₅, press Bi ₄M ₂O ₁₁The chemical formula weigh batching, wherein the M element is one or both among Nb, Ta and the V;

The above-mentioned chemical raw material that 2) will configure mixes, and puts into ball grinder, adds zirconia ball and absolute ethyl alcohol, and ball milling 8-10h mixes levigately, takes out oven dry, 200 mesh sieves;

3) the above-mentioned powder that mixes is 800-950 ℃ of pre-burning, and insulation 4-8h, naturally cools to room temperature, by ball milling particle diameter diminished then, reaches about 2 μ m, can obtain bismuth-system compound oxide photocatalyst Bi ₄M ₂O ₁₁Powder.