CN103623850A

CN103623850A - Preparation method of high-activity silver bromide nano-photocatalytic material

Info

Publication number: CN103623850A
Application number: CN201310538601.3A
Authority: CN
Inventors: 唐华; 张杜; 李长生; 王瑜琦
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2013-11-05
Filing date: 2013-11-05
Publication date: 2014-03-12

Abstract

The invention discloses a preparation method of a high-activity silver bromide nano-photocatalytic material. A surfactant, cetyl trimethyl ammonium bromide (CTAB), silver nitrate (AgNO3) and ammonia water (NH3.H2O) are taken as raw materials, and silver bromide nano-sheets are prepared by adopting a water bath method. The method for preparing the silver bromide nano-material, disclosed by the invention, has the advantages of simplicity, easiness in operation, mild reaction conditions, high yield and good reproducibility. When the nano-material is used as a photocatalyst, the catalytic performance is excellent.

Description

A kind of preparation method of high activity silver bromide nano-photocatalyst material

Technical field

The present invention relates to the preparation of catalysis material, specifically, is a kind of high activity silver bromide nano-photocatalyst material and preparation method thereof.

Background technology

In recent years, for oneself a great problem in becoming Industrial Wastewater Treatment of the processing of waste water from dyestuff; Because the features such as the toxicity of waste water from dyestuff is very large, colourity is higher, recyclability is poor make traditional biodegrading process can not effectively remove organic pigment wherein; The new technology of therefore seeking a kind of effectively dye wastewater treatment using is the emphasis that everybody pays close attention to always, and photocatalytic method operates compared with simple, reaction condition and is easier to that the advantages such as control, non-secondary pollution, oxidability is strong little by little become a kind of method of new degrading waste water and the attention that obtains people with it.

Light-catalyzed reaction can make organic matter all be degraded into inorganic acid, water and carbon dioxide etc., and silver halide photochemical catalyst also has that method of operating is simple, reaction condition is gentleer, it is low to consume energy simultaneously, use in extensive range and be difficult to reproduce into these advantages of secondary pollution; Nano-sized silver halide paricles is owing to having the features such as small-size effect, quantum confined effect and specific surface effect, compare with titanium dioxide, under visible ray, there is higher photocatalytic activity, under the condition of illumination, electron transition in silver bromide valence band has been arrived on conduction band, a large amount of electronics and hole have just been produced, hole and Br ^-further reaction generates hypobromous acid, hypobromous acid is under the effect of silver ion, decomposition produces oxygen, while reacting in the aqueous solution, under the exciting of luminous energy, first produce a large amount of electronics and hole, then water is decomposed and produces a large amount of highly active hydroxyl radical free radicals, these hydroxyl radical free radicals can be accelerated the decomposition of pollutant in environment, thereby improve photocatalytic degradation efficiency; Occurring in recent years some composite photocatalyst materials based on silver halide, is to have been introduced in 200810016609.2,200810016610.5,200810016611.X at number of patent application, but its preparation method and process are complicated.Thereby a kind of preparation method of high activity silver bromide nano-photocatalyst material proposed.

Summary of the invention

The present invention is directed to the problem that most catalysis material is low to sunshine utilization rate, propose a kind of preparation method of high activity silver bromide nano-photocatalyst material, method is simple, reaction condition is gentle.

The preparation of silver bromide nano-photocatalyst material of the present invention comprises the steps to carry out:

(1), under water bath with thermostatic control, surfactant-dispersed, in methyl-sulfoxide (DMSO) solution of softex kw (CTAB), is stirred to and is mixed;

(2) by AgNO ₃be dissolved in methyl-sulfoxide (DMSO) solution, dropwise add NH ₃h ₂o;

(3) solution (2) being prepared dropwise adds in (1) solution under stirring condition, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 60-180 ℃ of temperature, react 1-24 h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

The addition of the methyl-sulfoxide (DMSO) in step (1) and (2) is can dissolve softex kw and AgNO ₃be as the criterion; In further step (1), the quality of softex kw and the volume ratio of methyl-sulfoxide are: 8-32mg:1ml; AgNO in step (2) ₃quality and the volume ratio of methyl-sulfoxide be: 25-60mg:1ml.

Mixing speed in step (3) is 500 ~ 600rpm.

Water bath with thermostatic control described in step (1) is 60 ℃; Described surfactant is polyvinylpyrrolidone (PVP).

Described AgNO ₃with softex kw mass ratio be 3:8.

Described surfactant and softex kw mass ratio are 0.15 ~ 3.5:1.

Described NH ₃h ₂o mass fraction is 25 ~ 28%, step (2) methyl-sulfoxide used and NH ₃h ₂the volume ratio of O is 1:0.02 ~ 1:0.2.

Preparation method of the present invention is simple, reaction condition is gentle, experiment productive rate is high, pattern is controlled.Compare with existing AgBr material, have more excellent visible light photocatalysis performance, during illumination 50min, this material can reach more than 90% the degradation rate of rhodamine B.

Accompanying drawing explanation

Fig. 1 is the X-ray diffractogram of the embodiment of the present invention 1 product.

Fig. 2 is the scanning electron microscope (SEM) photograph of the embodiment of the present invention 1 product.

Fig. 3 is the photocatalytic degradation curve of the embodiment of the present invention 1 product to rhodamine B.

Fig. 4 is the scanning electron microscope (SEM) photograph of the embodiment of the present invention 2 products.

Fig. 5 is the photocatalytic degradation concentration ratio-time graph to rhodamine B of the embodiment of the present invention 3, embodiment 4, embodiment 5, embodiment 6, embodiment 7.

The specific embodiment

In order to understand better the present invention, below in conjunction with embodiment, the invention will be further described, but the scope of protection of present invention is not limited to the scope that embodiment represents.

Embodiment 1

(1) under 60 ℃ of waters bath with thermostatic control, get 54 mg surfactant PVP and be distributed in methyl-sulfoxide (DMSO) solution of 25mL containing the softex kw (CTAB) of 320 mg, be stirred to evenly.

(2) by the AgNO of 120 mg ₃join in methyl-sulfoxide (DMSO) solution of 5mL, then dropwise drip the NH of 150 μ L ₃h ₂o.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 500rpm, after stirring, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 60 ℃ of temperature, react 24 h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 2

(2) by the AgNO of 120 mg ₃join in methyl-sulfoxide (DMSO) solution of 5mL, then dropwise drip the NH of 500 μ L ₃h ₂o.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 600rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 100 ℃ of temperature, react 18h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 3

(1) under 60 ℃ of waters bath with thermostatic control, 200 mg softex kws (CTAB) are joined in 25mL methyl-sulfoxide (DMSO) solution, be stirred to and mix.

(2) by 75 mg AgNO ₃join in 5mL methyl-sulfoxide (DMSO) solution, dropwise add the NH of 1mL ₃h ₂o solution.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 550rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 80 ℃ of temperature, react 20h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 4

(1) under 60 ℃ of waters bath with thermostatic control, get 0.25g surfactant PVP and be distributed in methyl-sulfoxide (DMSO) solution of 25mL containing the softex kw (CTAB) of 320 mg, be stirred to evenly.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 500rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 180 ℃ of temperature, react 1h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 5

(1) under 60 ℃ of waters bath with thermostatic control, get 0.5g surfactant PVP and be distributed in methyl-sulfoxide (DMSO) solution of 25mL containing the softex kw (CTAB) of 480 mg, be stirred to and mix.

(2) by 180 mg AgNO ₃join in 5mL methyl-sulfoxide (DMSO) solution, dropwise add the NH of 1mL ₃h ₂o solution.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 600rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 160 ℃ of temperature, react 5h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 6

(1) under 60 ℃ of waters bath with thermostatic control, get 1.5g surfactant PVP and be distributed in methyl-sulfoxide (DMSO) solution of 25mL containing the softex kw (CTAB) of 640 mg, be stirred to and mix.

(2) by 240 mg AgNO ₃join in 5mL methyl-sulfoxide (DMSO) solution, dropwise add the NH of 1mL ₃h ₂o solution.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 550rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 120 ℃ of temperature, react 10h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Embodiment 7

(1) under 60 ℃ of waters bath with thermostatic control, get 2.5g surfactant PVP and be distributed in methyl-sulfoxide (DMSO) solution of 25mL containing the softex kw (CTAB) of 800 mg, be stirred to and mix.

(2) by 300 mg AgNO ₃join in 5mL methyl-sulfoxide (DMSO) solution, dropwise add the NH of 500 μ L ₃h ₂o solution.

(3) solution (2) being prepared dropwise adds in (1) solution under the stirring condition of 600rpm, after stirring 30min, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 180 ℃ of temperature, react 1h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

Fig. 1 is the XRD figure of prepared AgBr nano-photocatalyst material, and as can be seen from the figure this nano material is pure AgBr, there is no other material; Fig. 2 is the SEM figure of prepared AgBr nano-photocatalyst material, and AgBr presents laminated structure as can be seen from Figure; Fig. 3 is that prepared AgBr nano-photocatalyst material is 1 * 10 to concentration ^-5the photocatalytic degradation curve of the rhodamine B solution of mol/L, as can be seen from the figure, under the radiation of visible light that is 400-700nm at wavelength, within first 10 minutes, photocatalytic degradation effect is very fast, later stage degradation rate reduction, but illumination 50min degradation rate can reach more than 90%; Fig. 4 is the SEM figure of prepared AgBr nano-photocatalyst material, and AgBr presents particulate species chondritic as can be seen from Figure, and size homogeneous is rough, has a little particle to produce; Fig. 5 is photocatalytic degradation concentration ratio-time graph, and as can be seen from the figure different PVP content is larger on its photocatalysis performance impact, and while not adding PVP, its photocatalysis effect is poor, adds appropriate PVP and can improve its photocatalytic degradation effect.

Claims

1. a preparation method for high activity silver bromide nano-photocatalyst material, described silver bromide nano-photocatalyst material is 1 * 10 to concentration ^-5the rhodamine B solution of mol/L, under the radiation of visible light that is 400-700nm at wavelength, illumination 50min degradation rate can reach more than 90%, it is characterized in that, carries out as follows:

(1), under water bath with thermostatic control, surfactant-dispersed, in the dimethyl sulfoxide solution of softex kw, is stirred to and is mixed;

(2) by AgNO ₃be dissolved in dimethyl sulfoxide solution, dropwise add NH ₃h ₂o;

(3) solution (2) being prepared dropwise adds in (1) solution under stirring condition, after stirring, this mixed solution is proceeded in the stainless steel cauldron that polytetrafluoroethylene (PTFE) is liner, at 60-180 ℃ of temperature, react 1-24 h, then centrifugation, collect product, and obtain nanometer Ag Br with deionized water, acetone and absolute ethanol washing, vacuum drying.

2. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, the addition of the methyl-sulfoxide (DMSO) in step (1) and (2) is can dissolve softex kw and AgNO ₃be as the criterion.

3. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 2, is characterized in that, in step (1), the quality of softex kw and the volume ratio of methyl-sulfoxide are: 8-32mg:1ml; AgNO in step (2) ₃quality and the volume ratio of methyl-sulfoxide be: 25mg-60mg:1ml.

4. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, the temperature of the water bath with thermostatic control that step (1) is described is 60 ℃; Described surfactant is polyvinylpyrrolidone.

5. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, AgNO used ₃with softex kw mass ratio be 3:8.

6. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, described surfactant and softex kw mass ratio are 0.15 ~ 3.5:1.

7. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, described NH ₃h ₂o mass fraction is 25 ~ 28%, step (2) methyl-sulfoxide used and NH ₃h ₂the volume ratio of O is 1:0.02 ~ 1:0.2.

8. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that, the mixing speed in step (3) is 500 ~ 600rpm.

9. the preparation method of a kind of high activity silver bromide nano-photocatalyst material as claimed in claim 1, is characterized in that prepared silver bromide nano-photocatalyst material, and pattern is octahedra particle, and size is 100 nm ~ 1 μ m.