CN100478070C - Preparing process of visible light responsive photocatalyst - Google Patents

Abstract

It relates to photo catalytic material for environment contamination treatment. It is YMO3, with M either In or Al, in the structure of perovskite with cubic phase (Y0.5In0.5)2O3. It uses yttrium nitrate or aluminum nitrate as oxidizer, octopinic acid as the fule, burning in conic solution or distillate in 300-400DEG C temperature to get the nanometer powder hydrate, baking 1-12 hours in the temperature 1000-1200DEG C to get YInO3 or YAlO3. The reaction formula is like this: 3Y(NO3)3+3M(NO3)3+10C2H5NO2=3YMO3+14N2+25H2O+20CO2. It has low content of impurity, stable in structure, stable photo catalytic activation, meeting photo catalytic and purification requirement free from ultra violet indoor. It has low synthesizing temperature, simple process and low cost.

Description

A kind of visible light responsive photocatalyst preparation method

Technical field

The present invention relates to the to curb environmental pollution catalysis material and the preparation of usefulness also relate to the low-temperature burning synthetic technology.

Background technology

Along with the raising of industrial expansion and living standards of the people, problem of environmental pollution has been mentioned very important agenda, develops efficient, energy-conservation, the environmental improvement of non-secondary pollution, the environmental protection new technology especially is subjected to people's attention.In all kinds of new technologies, photocatalysis technology is 21 century one of the most promising environmental friendliness cleaning new technology, and it is a process of utilizing light absorbing energy decomposing organic matter of photochemical catalyst or decomposition water.Its mechanism is that the electronics in the semiconductor valence band is subjected to optical excitation to transit to conduction band, forms light induced electron in conduction band, stays photohole in valence band.There are extremely strong reduction and oxidability in the electronics of these nonequilibrium state and hole.When they are diffused into photochemical catalyst surperficial, the pollutant redox can be become harmless little molecule, or be H water decomposition ₂And O ₂Because photocatalysis can utilize natural daylight (for example sunshine) long-term work, has the advantage of low cost, nonhazardous, for fundamentally solving environmental pollution and the energy shortage problem has immeasurable meaning.

Practical catalysis material need have stronger extinction ability, and the nonequilibrium state electronics of long period, hole life and higher electronics, hole mobility.How to find suitable catalysis material is the research topic that scientific and technical personnel pay close attention to always.Correlative study over nearly 30 years is mainly round with TiO ₂Serial wide bandgap semiconductor for the basis.Yet because TiO ₂The forbidden band wide, cause TiO ₂Can only absorb the light of ultraviolet band.From being used to of solar energy, ultraviolet ray (400nm is following) only accounts for about 4% of sunshine gross energy, and wavelength is that the visible light of 400-750nm then accounts for nearly 43%.Therefore, in order to effectively utilize solar energy, satisfy the demand of indoor no UV environment light catalytic purifying simultaneously, it is imperative to seek visible light-responded photochemical catalyst.

Summary of the invention

The object of the invention is, a kind of photochemical catalyst YMO that has light degradation organic pollution performance under the visible light condition is provided ₃(M=In, Al) and preparation method thereof.

Visible light responsive photocatalyst of the present invention is characterized in that, it is compound YMO ₃, wherein M is In or Al, YAlO ₃Structure be Ca-Ti ore type, YInO ₃Be (Y with cube phase _0.5In _0.5) ₂O ₃, promptly its structure is a cube phase, structural formula is (Y _0.5In _0.5) ₂O ₃This photochemical catalyst can be by the preparation of following method: by yttrium nitrate and indium nitrate or aluminum nitrate is that oxidant, organic carboxyl acid amion acetic acid are fuel, obtain the nanometer grade powder compound through 300～400 ℃ of low-temperature burnings generation redox reactions in deionized water or distilled water solution, again the YInO that roasting obtained in 1～12 hour in 1000～1200 ℃ of environment ₃Or YAlO ₃, wherein yttrium nitrate and indium nitrate or aluminum nitrate mol ratio are 1: 1, and indium nitrate or aluminum nitrate and amion acetic acid mol ratio are 3: 10, and amount of water is that 0.1～0.2 mol is calculated according to yttrium nitrate solution concentration, and its chemical equation is:

3Y(NO ₃) ₃+3M(NO ₃) ₃+10C ₂H ₅NO ₂＝3YMO ₃+14N ₂↑+25H ₂O↑+20CO ₂↑。

The above-mentioned visible light responsive photocatalyst YMO of preparation of the present invention ₃(M=In, method Al) comprise that batching, mixing and low-temperature burning are synthetic, it is characterized in that concrete steps are: 1) with yttrium nitrate (Y (NO ₃) ₃), indium nitrate (In (NO ₃) ₃) or aluminum nitrate (Al (NO ₃) ₃), organic-fuel amion acetic acid (NH ₂CH ₂COOH) and deionized water or distilled water water mixing wiring solution-forming, and the solution after will preparing makes its even mixing through stirring, left standstill under room temperature 12～24 hours the back, wherein the mol ratio of yttrium nitrate and indium nitrate or aluminum nitrate is 1: 1, indium nitrate or aluminum nitrate and amion acetic acid mol ratio are 3: 10, and amount of water is that 0.1～0.2 mol is calculated according to yttrium nitrate solution concentration; 2) above-mentioned solution slowly is warmed up to 300～400 ℃, for example earlier solution was placed 150～200 ℃ of following constant temperature 20～60 minutes, slowly be warmed up to 300～400 ℃ with 2～4 ℃/minute speed again, make the concurrent intercrescence of burning of organic-fuel in the solution become reaction, obtain fluffy nanometer YMO ₃(its chemical equation is for M=In, Al) powder:

3Y(NO ₃) ₃+3M(NO ₃) ₃+10C ₂H ₅NO ₂＝3YMO ₃+14N ₂↑+25H ₂O↑+20CO ₂↑；

3) with above-mentioned nano-powder 1000～1200 ℃ of following roastings 1～12 hour, finished product YInO ₃Or YAlO ₃

Visible light responsive photocatalyst YMO of the present invention ₃(M=In, Al), the product impurity content is low, Stability Analysis of Structures.Test result shows, this catalyst YMO ₃In visible light wave range, has stronger extinction ability, and the nonequilibrium state electronics of long period, hole life and higher electronics, hole mobility, can absorb the visible light part in the sunshine, and under radiation of visible light, has stable photocatalytic activity, the demand of light catalytic purifying in the time of can satisfying indoor no UV environment.

Preparation method of the present invention is based on principle of oxidation and reduction, with nitrate is oxidant, organic carboxyl acid is a fuel, batching provides the required oxidant that burns, guarantee the oxygen demand of organic-fuel in the subsequent combustion reaction and the oxygen content balance that nitrate provides, reaction can also fully be carried out by rapid spread, until running out of gas.This preparation method has the following advantages:

1. be reflected in the solution and carry out, can reach the even mixing of molecular level, synthesis temperature is low;

2. preparation technology is simple, and required time is short, and expense is low.

3. do not need long-time grinding, impurity content is low in the product, thereby has guaranteed stable photocatalytic activity.

Description of drawings

Fig. 1 is the prepared YInO of the embodiment of the invention 1 and embodiment 2 ₃And YAlO ₃XRD test curve before and after it carries out the photocatalytic activity reaction.

Fig. 2 is to the prepared YInO of the embodiment of the invention 1 and embodiment 2 ₃And YAlO ₃Carry out the result of photocatalytic activity test.

The specific embodiment

Embodiment 1

(1) takes by weighing 2.75 gram Y (NO ₃) ₃, 3.819 the gram

2.5 gram organic-fuel C ₂H ₅NO ₂, put into 100 ml beakers, add 50 ml deionized water, stir it is evenly mixed after, solution was left standstill under room temperature 24 hours;

(2) get above-mentioned solution and place 100 ml beakers for about 20 milliliters, beaker was placed 200 ℃ of following constant temperature 30 minutes;

(3) slowly be warming up to 300 ℃ by 3 ℃ of/minute clock rate then the solution in the container is fully burnt, obtain fluffy YInO ₃Powder;

(4) above-mentioned combustion powder is placed 1100 ℃ of following roastings 10 hours, get finished product YInO ₃

This finished product is carried out X-ray diffraction (being called for short XRD) test, and it the results are shown in Fig. 1.YInO among Fig. 1 before the light-catalyzed reaction ₃Curve shows the (Y of this synthetic sample for cube phase _0.5In _0.5) ₂O ₃

Embodiment 2

(1) takes by weighing 2.75 gram Y (NO ₃) ₃, 3.751 gram Al (NO ₃) ₃9H ₂O, 2.5 gram organic-fuel C ₂H ₅NO ₂, put into 100 ml beakers, add 50 ml deionized water, stir after 30 minutes, solution was left standstill under room temperature 24 hours;

(2) get above-mentioned solution and place 100 ml beakers for about 20 milliliters, beaker was placed 200 ℃ of following constant temperature 30 minutes;

(3) slowly be warming up to 300 ℃ by 3 ℃ of/minute clock rate then the solution in the container is fully burnt, obtain fluffy YAlO ₃Powder;

(4) above-mentioned combustion powder is placed 1100 ℃ of following roastings 10 hours, get finished product YAlO ₃

YAlO among Fig. 1 before the reaction ₃Curve is the X-ray diffractogram of this synthetic sample, shows that this synthetic sample is pure phase Ca-Ti ore type YAlO ₃

Fig. 2 is YInO ₃And YAlO ₃The photocatalytic activity result.It is visible light source that test experiments adopts the 150W halogen tungsten lamp, and catalyst amount is 0.45 gram, and methylene blue solution concentration is 23.9 micromoles per liter, and volume is 150 milliliters.In order to remove ultraviolet light and the fuel factor in the halogen tungsten lamp, add a double-deck pyroceram sleeve pipe of taking back flowing water at fluorescent tube.Liquid is left standstill in the reaction of extracting at set intervals about 5 milliliters, adopts the spectrophotometric determination solution absorbency, weighs activity of such catalysts according to the fade rates of methylene blue.The result shows, YInO ₃System used about 110 minutes methylene blue to be degraded fully YAlO ₃The system light degradation methylene blue time is about 90 minutes.Reaction end back adding methylene blue is done for the second time, and photocatalytic activity characterizes YInO ₃And YAlO ₃System still only used just methylene blue is degraded fully in about 110 minutes and 90 minutes, showed that institute's synthetic catalyst has stable photocatalytic activity under radiation of visible light.

Fig. 1 has listed file names with the XRD result of photochemical catalyst, YInO as can be seen after the light-catalyzed reaction ₃And YAlO ₃Crystal structure before and after reaction does not change, and this shows that this catalyst structure is stable.

Embodiment 3

(1) takes by weighing 5.50 gram Y (NO ₃) ₃, 7.638 the gram

5.0 gram organic-fuel C ₂H ₅NO ₂, put into 250 ml beakers, add 100 ml deionized water, stir after 60 minutes, solution was left standstill under room temperature 12 hours;

(2) get above-mentioned solution and place 100 ml beakers for about 30 milliliters, beaker was placed 150 ℃ of following constant temperature 60 minutes;

(3) slowly be warming up to 350 ℃ by 4 ℃ of/minute clock rate then the solution in the container is fully burnt, obtain fluffy YInO ₃Powder places 1020 ℃ of following roastings 12 hours with this powder, gets finished product YInO ₃

Embodiment 4

(1) takes by weighing 5.50 gram Y (NO ₃) ₃, 7.502 gram Al (NO ₃) ₃9H ₂O, 5.0 gram organic-fuel C ₂H ₅NO ₂, put into 250 ml beakers, add 100 ml distilled waters, stir and it was fully mixed in 60 minutes, then solution was left standstill under room temperature 18 hours;

(2) get above-mentioned solution and place 100 ml beakers for about 30 milliliters, beaker was placed 150 ℃ of following constant temperature 60 minutes;

(3) slowly be warming up to 400 ℃ by 4 ℃ of/minute clock rate then the solution in the container is fully burnt, obtain fluffy YAlO ₃Powder places 1200 ℃ of following roastings 2 hours with this powder, gets finished product YAlO ₃

Claims (2)

1. visible light responsive photocatalyst YMO ₃The preparation method, described YMO ₃, wherein M is In or Al, YAlO ₃Structure be Ca-Ti ore type, YInO ₃Be (Y with cube phase _0.5In _0.5) ₂O ₃, described preparation method comprises that batching, mixing and low-temperature burning are synthetic, it is characterized in that concrete steps are:

1) with yttrium nitrate, indium nitrate or aluminum nitrate, organic-fuel amion acetic acid and deionized water or distilled water mixing wiring solution-forming, and the solution after will preparing makes its even mixing through stirring, left standstill under room temperature 12～24 hours the back, wherein yttrium nitrate and indium nitrate or aluminum nitrate mol ratio are 1: 1, indium nitrate or aluminum nitrate and amion acetic acid mol ratio are 3: 10, and amount of water is that 0.1～0.2 mol is calculated according to yttrium nitrate solution concentration;

2) above-mentioned solution slowly is warmed up to 300～400 ℃, makes the concurrent intercrescence of burning of organic-fuel in the solution become reaction, obtain nanometer YMO ₃Powder, its chemical equation is: 3Y (NO ₃) ₃+ 3M (NO ₃) ₃+ 10C ₂H ₅NO ₂=3YMO ₃+ 14N ₂↑+25H ₂O ↑+20CO ₂↑;

3) with above-mentioned nano-powder 1000～1200 ℃ of following roastings 1～12 hour, finished product YInO ₃Or YAlO ₃

2. preparation method as claimed in claim 1 is characterized in that, describedly slowly is warmed up to 300～400 ℃, is earlier solution to be placed 150～200 ℃ of following constant temperature 20～60 minutes, slowly is warmed up to 300～400 ℃ with 2～4 ℃/minute speed again.

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