CN102500371A - Visible light response photocatalysis material Ag@Ag3VO4 and preparation method thereof - Google Patents

Abstract

The invention relates to a visible light responsive photocatalysis material Ag@Ag3VO4 and a preparation method thereof. The Ag@Ag3VO4 photocatalysis material is of a near-spherical composite structure of depositing silver nano granules on the surfaces of silver vanadate granules, wherein the silver vanadate granules have the diameter of 6.5-7.5 mu m, and the surface deposited nano granules have the particle size of 5-25 nm. The invention also provides a preparation method of Ag@Ag3VO4. According to the invention, silver is deposited and loaded on the surface of Ag3VO4, thus the photocatalysis performance of Ag3VO4 is farther improved; and the method has the advantages of simple method, mild reaction conditions, convenience for operation, low energy consumption and the like.

Description

Visible light responsible photocatalytic material AgAg 3VO 4And preparation method thereof

Technical field

The present invention relates to a kind of micro-nano catalysis material AgAg ₃VO ₄And preparation method thereof, belong to the synthetic field of micro-nano photocatalysis powder material.

Background technology

In recent years; Along with expanding economy, the energy and environmental problem become increasingly conspicuous, and environmental pollution has brought huge harm for Human's production and life; Especially the pollution of water resource has jeopardized the healthy of the mankind, and the method for being badly in need of feasibility is disposed of sewage.Traditional method administer water pollute exist that power consumption is big, complex equipments, expense are high, be prone to bring shortcoming such as secondary pollution.Therefore, develop the focus that a kind of novel, efficient, practical environmental protection treatment technology becomes people's research.Along with going deep into of research; It is found that the heterogeneous photocatalysis technology of semiconductor comes degradable organic pollutant through environmentally friendly redox reaction; Have that energy consumption is low, easy and simple to handle, reaction condition is gentle, usage range is wide, can reduce advantages such as secondary pollution, thereby aspect waste water control, more and more receive people's attention.

Ag ₃VO ₄Catalysis material as vanadate series can utilize the visible light part in the luminous energy, is typical low energy gap catalysis material, and very big actual application value is arranged.But the same with most of catalysis material, Ag ₃VO ₄Also exist the recombination rate of photo-generated carrier higher, the problem that quantum efficiency is low.Ag ₃VO ₄The preparation of catalysis material comprises high temperature solid-state and co-precipitation combined techniques, and hydro-thermal method is the Ag of synthetic monoclinic structure directly ₃VO ₄Material is through the modulation temperature series A g synthetic with adding polyethylene glycol ₃VO ₄Material.These synthetic methods all exist complicated operation, and step is various, shortcomings such as big energy-consuming.

Summary of the invention

To the deficiency of prior art, the present invention provides a kind of visible light-responded catalysis material AgAg ₃VO ₄And preparation method thereof.

Term explanation: AgAg ₃VO ₄, be meant that silver is coated on the composite of vanadic acid silver outer surface.

A kind of visible light-responded catalysis material AgAg ₃VO ₄Be that wherein, vanadic acid silver is monoclinic scheelite-type structure at the near-spherical composite construction catalysis material of vanadic acid silver particle surface depositing silver nano particle; Vanadic acid silver particle diameter is 6.5 μ m-7.5 μ m, and the silver nano-grain particle diameter of surface deposition is 5nm-25nm.The mol ratio that silver nano-grain accounts for vanadic acid silver is 3-5%.

Technical scheme of the present invention is following:,

Visible light responsible photocatalytic material AgAg of the present invention ₃VO ₄The preparation method, comprise the steps:

(1) prepares the AgNO of 0.3mol/L respectively ₃The NaVO of solution, 0.1mol/L ₄The NaOH solution of solution and 1mol/L;

(2) press AgNO ₃: NaVO ₄=3.05-3.15: 1 mol ratio, with the NaVO of 0.1mol/L ₄Drips of solution is added to the AgNO of 0.3mol/L ₃In the solution, stir, dropwise continued and stirred 10-15 minute while dripping; Use the NaOH solution regulation system pH value of 1mol/L to be 7.0-8.0;

(3) suspension with step (2) is transferred in the teflon-lined agitated reactor, compactedness 70%-80% volume ratio, and 180-200 ℃ was reacted 24-30 hour down.Reaction is cooled to room temperature after finishing, and with deionized water and absolute ethanol washing, in 50-60 ℃ of dry 5-12 hour, gets micro-nano powder materials A gAg ₃VO ₄

Preferred according to the present invention, AgNO in the step (1) ₃With NaVO ₄Mol ratio is 3.09: 1.

Preferred based on the present invention, during with the NaOH solution regulation system pH value of 1mol/L, in dripping NaOH solution process, need fully to stir in the step (2), regulate pH to 8.0, continuation stirring 20-30 minute.

Preferred based on the present invention, reaction in the step (3) and oven dry are in baking oven, to carry out.The preferred reaction time is 24 hours; Be 12 hours preferred drying time.Preferably, baking temperature is 60 ℃.

Further preferred according to the present invention, a kind of visible light responsible photocatalytic material AgAg ₃VO ₄The preparation method, step is following:

Get the NaVO of 0.1mol/L ₄Solution 30ml splashes into the AgNO of 30.9ml 0.3mol/L ₃In the solution, stir while dripping, continued magnetic agitation 10 minutes after dripping off, the NaOH solution that adds 1mol/L is regulated pH to 8.0, stirs AgNO in the solution in the adjustment process simultaneously ₃: NaVO ₄=3.09: 1 mol ratio, pH regulates to finish and continues to stir 30 minutes, and in the 100ml polytetrafluoroethylene (PTFE) agitated reactor of packing into then, compactedness 80% volume ratio is put into 180 ℃ of reactions of baking oven 24 hours; After reaction finishes, naturally cool to room temperature, suction filtration with deionized water and ethanol cyclic washing 3 times, was put into 60 ℃ of dryings of baking oven 12 hours; Get micro-nano powder materials A gAg ₃VO ₄, vanadic acid silver particle diameter is 6.5-7.5 μ m, the silver granuel of surface deposition directly is 5-25nm.

AgAg of the present invention ₃VO ₄The specific area of catalysis material is 0.5-3m ²/ g can be used for degradation of organic substances.

Visible light responsible photocatalytic material AgAg of the present invention ₃VO ₄Application, be applied to the removal of organic pollution in air, waste water, surface water or the drinking water, or the photocatalysis that is used for heavy metal ion is removed.

Excellent results of the present invention is following:

1. visible light responsible photocatalytic material AgAg of the present invention ₃VO ₄Shape characteristic be near-spherical Ag ₃VO ₄, and at Ag ₃VO ₄Area load the Ag nano particle.This catalysis material is visible light-responded, finds that through experiment test the material of this structure has the Ag of ratio in the visible region ₃VO ₄Wideer absorption region.

The present invention through the reduction silver ion method at Ag ₃VO ₄The surface is with Ag ⁺In-situ reducing becomes Ag ⁰, single step reaction forms AgAg ₃VO ₄Composite construction, at its surface deposition noble metal silver, and the local surface plasma resonance effect (LSPR) through silver to be to reach the recombination rate that reduces photo-generated carrier, and the purpose of raising quantum yield has improved Ag to a great extent ₃VO ₄The photocatalysis effect.

3. owing to the effect of silver nanoparticles loaded, the photocatalytic activity of this catalysis material is apparently higher than Ag ₃VO ₄Titanium dioxide (Degussa P25) with commercial applications.

4. visible light responsible photocatalytic material AgAg of the present invention ₃VO ₄The preparation method is simple, with low cost, the synthetic method mild condition has higher commercial application prospect.

Find Ag through experimental study ₃VO ₄Behind loaded Ag, AgAg ₃VO ₄The photocatalytic activity of degraded rhodamine B compares Ag ₃VO ₄Improve more than 4 times, then improved more than 25 times than the activity of commerce with titanium dioxide (Degussa P25), this is because at Ag/Ag ₃VO ₄The local surface plasma resonance effect (LSPR) of the silver that the surface forms has reached the recombination rate that reduces photo-generated carrier, improves quantum yield, thereby has improved photocatalytic activity.

Description of drawings

Fig. 1 is the SEM figure of embodiment 1 product, and a～c shows AgAg ₃VO ₄Pattern, d shows Ag ₃VO ₄The Ag particle on surface.Fig. 2 is the X-ray diffractogram of embodiment 1 product, and * is the diffraction maximum of Ag.

Fig. 3 is embodiment 1 product A gAg ₃VO ₄With embodiment 2 product A g ₃VO ₄, and the degradation curve comparison diagram of commercial P25 degraded rhodamine B; Abscissa is that the time, (unit: min), ordinate was the initial concentration (C of concentration (C)/rhodamine B of the rhodamine B of degraded certain hour ₀).

Fig. 4 is embodiment 1 product A gAg ₃VO ₄With embodiment 2 product A g ₃VO ₄UV-Vis diffuse reflectance spectra comparison diagram.Abscissa is that (unit: nm), ordinate is absorptivity (arbitrary unit) to wavelength.

The specific embodiment

, but be not limited thereto further specifying among the present invention below in conjunction with accompanying drawing.

It is following among the embodiment prepared material to be carried out the method for photocatalytic activity test:

Photocatalysis test (cross section 30cm in glass beaker ², high 5cm) carry out under the normal temperature and pressure.Light source is selected the 500W xenon lamp that optical filter is housed for use, makes optical source wavelength greater than 400nm.Come the photocatalytic activity of assess sample with rhodamine B.Take by weighing the 0.1g sample dispersion in 100mL rhodamine B solution (20mg/L).Before the light-catalyzed reaction test, lucifuge magnetic agitation 30min makes rhodamine B reach adsorption equilibrium at catalyst surface, and every at a distance from 15min sampling 5ml behind the logical light, centrifugation is got supernatant and used the measurement of ultraviolet-visible spectrophotometer absorbance.As a comparison, use Ag ₃VO ₄Under equal experiment condition, carried out the photocatalytic activity test with P25 with commerce.

Embodiment 1

Get the NaVO of 0.1mol/L ₄Solution 30ml slowly splashes into the AgNO of 30.9ml 0.3mol/L ₃In the solution, stir while dripping, continued magnetic agitation 10 minutes after dripping off, the NaOH solution that adds 1mol/L is regulated pH to 8.0, stirs AgNO in the solution in the adjustment process simultaneously ₃: NaVO ₄=3.09: 1 mol ratio, pH regulates to finish and continues to stir 30 minutes, and in the 100ml polytetrafluoroethylene (PTFE) agitated reactor of packing into then, compactedness 80% volume ratio is put into 180 ℃ of reactions of baking oven 24 hours.After reaction finishes, naturally cool to room temperature, suction filtration with deionized water and ethanol cyclic washing 3 times, was put into 60 ℃ of dryings of baking oven 12 hours.Get micro-nano powder materials A gAg ₃VO ₄, electromicroscopic photograph is as shown in Figure 1, and vanadic acid silver particle diameter is 6.5-7.5 μ m, and the silver granuel of surface deposition directly is 5-25nm.Fig. 2 is the X-ray diffractogram of sample for this reason, and this product diffraction maximum is Ag ₃VO ₄Coexist with Ag.

Embodiment 2

0.1mol/L NaVO ₄Solution 30ml slowly splashes into the AgNO of 30.0ml 0.3mol/L ₃In the solution, stir while dripping, magnetic agitation is 10 minutes after dripping off, and the NaOH solution that adds 1mol/L is regulated pH to 6.5, stirs AgNO in the solution in the adjustment process simultaneously ₃: NaVO ₄=3: 1 mol ratio, pH regulates to finish and continues to stir 30 minutes, and in the 100ml polytetrafluoroethylene (PTFE) agitated reactor of packing into then, compactedness 80% volume ratio is put into 170 ℃ of reactions of baking oven 20 hours.After reaction finishes, naturally cool to room temperature, suction filtration with deionized water and ethanol cyclic washing 3 times, was put into 60 ℃ of dryings of baking oven 10 hours, and resulting sample is Ag ₃VO ₄, in Fig. 2, Fig. 3 as AgAg ₃VO ₄Contrast.

Embodiment 3

0.1mol/L NaVO ₄Solution 30ml slowly splashes into the AgNO of 31.5ml 0.3mol/L ₃In the solution, stir while dripping, magnetic agitation is 10 minutes after dripping off, and the NaOH solution that adds 1mol/L is regulated pH to 8.0, stirs AgNO in the solution in the adjustment process simultaneously ₃: NaVO ₄=3.15: 1, pH regulates to finish and continues to stir 30 minutes, in the 100ml polytetrafluoroethylene (PTFE) agitated reactor of packing into then, fills 70%, puts into 180 degrees centigrade of reactions of baking oven 24 hours.After reaction finishes, naturally cool to room temperature, suction filtration with deionized water and ethanol cyclic washing 3 times, was put into 60 degrees centigrade of dryings of baking oven 12 hours.That obtain is AgAg ₃VO ₄

Claims (6)

1. visible light-responded catalysis material AgAg ₃VO ₄, it is characterized in that, be near-spherical composite construction at vanadic acid silver particle surface depositing silver nano particle; Wherein, Vanadic acid silver is monoclinic scheelite-type structure, and vanadic acid silver particle diameter is 6.5 μ m-7.5 μ m, and the silver nano-grain particle diameter of surface deposition is 5nm-25nm; The mol ratio that silver nano-grain accounts for vanadic acid silver is 3-5%.

2. the said visible light responsible photocatalytic material AgAg of claim 1 ₃VO ₄The preparation method, comprise the steps:

(1) prepares the AgNO of 0.3mol/L respectively ₃The NaVO of solution, 0.1mol/L ₄The NaOH solution of solution and 1mol/L;

(2) press AgNO ₃: NaVO ₄=3.05-3.15: 1 mol ratio, with the NaVO of 0.1mol/L ₄Drips of solution is added to the AgNO of 0.3mol/L ₃In the solution, stir, dropwise continued and stirred 10-15 minute while dripping; Use the NaOH solution regulation system pH value of 1mol/L to be 7.0-8.0;

(3) suspension with step (2) is transferred in the teflon-lined agitated reactor, compactedness 70%-80% volume ratio, and 180-200 ℃ was reacted 24-30 hour down.Reaction is cooled to room temperature after finishing, and with deionized water and absolute ethanol washing, in 50-60 ℃ of dry 5-12 hour, gets powder body material AgAg ₃VO ₄

3. according to the said visible light responsible photocatalytic material AgAg of claim 2 ₃VO ₄The preparation method, it is characterized in that AgNO in the step (1) ₃With NaVO ₄Mol ratio is 3.O9: 1.

4. according to the said visible light responsible photocatalytic material AgAg of claim 2 ₃VO ₄The preparation method, it is characterized in that, during with the NaOH solution regulation system pH value of 1mol/L, in dripping NaOH solution process, need fully to stir in the step (2), regulate pH to 8.0, continuation stirring 20-30 minute.

5. according to the said visible light responsible photocatalytic material AgAg of claim 2 ₃VO ₄The preparation method, it is characterized in that reaction in the step (3) and oven dry are in baking oven, to carry out; The preferred reaction time is 24 hours; Be 12 hours preferred drying time; Preferred baking temperature is 60 ℃.

6. according to the said visible light responsible photocatalytic material AgAg of claim 2 ₃VO ₄The preparation method, it is characterized in that step is following:

Get the NaVO of 0.1mol/L ₄Solution 30ml splashes into the AgNO of 30.9ml 0.3mol/L ₃In the solution, stir while dripping, continued magnetic agitation 10 minutes after dripping off, the NaOH solution that adds 1mol/L is regulated pH to 8.0, stirs AgNO in the solution in the adjustment process simultaneously ₃: NaVO ₄=3.09: 1 mol ratio, pH regulates to finish and continues to stir 30 minutes, and in the 100ml polytetrafluoroethylene (PTFE) agitated reactor of packing into then, compactedness 80% volume ratio is put into 180 ℃ of reactions of baking oven 24 hours; After reaction finishes, naturally cool to room temperature, suction filtration with deionized water and ethanol cyclic washing 3 times, was put into 60 ℃ of dryings of baking oven 12 hours; Get micro-nano powder materials A gAg ₃VO ₄, vanadic acid silver particle diameter is 6.5-7.5 μ m, the silver granuel of surface deposition directly is 5-25nm.

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