CN104492464A

CN104492464A - Preparation method of silver iodide/beta type bismuth oxide composite material

Info

Publication number: CN104492464A
Application number: CN201510010668.9A
Authority: CN
Inventors: 张正媛; 姜德立; 陈敏; 贺敏强; 邢潮胜; 陈琳琳
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2015-01-09
Filing date: 2015-01-09
Publication date: 2015-04-08
Anticipated expiration: 2035-01-09
Also published as: CN104492464B

Abstract

The invention relates to a preparation method of a silver iodide/beta type bismuth oxide composite material. The preparation method particularly comprises the following steps: weighing beta-Bi2O3 powder, dissolving the beta-Bi2O3 powder into purified water, carrying out ultrasonic dispersion, then adding with AgNO3, magnetically stirring until the AgNO3 is dissolved completely, dropwise adding KI solution under a dark condition, magnetically stirring for reaction, centrifuging, washing with water, washing with alcohol for a plurality of times, and drying to obtain the silver iodide/beta type bismuth oxide composite material, wherein granular AgI is deposited on the sheet-like beta-Bi2O3. The preparation process is simple, and the prepared composite material has good photocatalytic activity.

Description

The preparation method of a kind of silver iodide/β type bismuth oxide composite

Technical field

The present invention relates to the preparation method of a kind of silver iodide/β type bismuth oxide composite, especially a kind of preparation technology is simple, has the composite material and preparation method thereof of good photocatalytic activity.

Background technology

In recent years, because Photocatalitic Technique of Semiconductor is in the potential application in the fields such as environment, material and the energy, searching and optimization high efficiency photocatalyst have obtained extensive concern; So far, in numerous semiconductor catalyst, Bi ₂o ₃as P-type semiconductor material, there is band gap narrow (~ 2.8eV), high oxidation hole, the feature such as nontoxic, has good application prospect in catalysis, bismuth oxide sterling has α type, β type, γ type, δ type and ω type, and different patterns, class as nano wire, nano particle, nanometer sheet and 3D Nano microsphere; Wherein report β-Bi ₂o ₃nanometer sheet due to its band gap narrow, the strong absorption of visible region and its design feature, have higher photocatalytic activity, but, β-Bi ₂o ₃photochemical catalyst is also faced with some problems, compound as easy in photo-generate electron-hole, and quantum efficiency is very low, therefore many modified beta-Bi ₂o ₃the method of semiconductor catalyst produces in succession, as: build heterojunction structure, change pattern, modify its body structure surface etc.; In these methods, hetero-junctions configuration is formed (such as: Bi with other semiconductors ₂wO ₆, BiVO ₄, Co ₃o ₄, TiO ₂, BaTiO ₃, BiOCl, Fe ₃o ₄and ZnO) be a kind of simple method, can effectively improve its photocatalysis efficiency.

Silver halide (AgX, X=Cl, Br, I) is as photosensitive materials, and it also has wide practical use in photocatalysis field, by AgX modifying semiconductor photochemical catalyst, can significantly increase its photocatalytic activity; In recent years, existing many reports about AgX-semi-conducting material heterojunction photocatalyst, as AgX/TiO ₂, AgI/BiOI, AgX/Ag ₃pO ₄and AgX/g-C ₃n ₄deng; Because the band gap of AgI is narrower than the band gap of AgCl and AgBr, therefore, meaning is had more with AgI modifying semiconductor material.

Up to now, not yet finding that there is people adopts water sedimentation legal system for AgI/ β-Bi ₂o ₃composite, β-Bi used ₂o ₃chemistry and physical property are stablized, and raw material are cheap and easy to get, nontoxic, and with it for carrier prepares AgI/ β-Bi ₂o ₃the reaction process of composite is simple, and products obtained therefrom photocatalytic activity is good.

Summary of the invention

The object of the invention be to provide a kind of newly at ambient temperature, with simple water sedimentation method synthesis AgI/ β-Bi ₂o ₃the method of composite.

The present invention is realized by following steps:

(1) sheet β type bismuth oxide (β-Bi is prepared ₂o ₃): take a certain amount of five water bismuth nitrates in beaker, add a certain amount of glacial acetic acid wherein and be stirred to entirely molten, then add a certain amount of absolute ethyl alcohol wherein, stir 20 min, then gained settled solution being transferred to liner is in the reactor of polytetrafluoroethylene (PTFE), puts into baking oven, hydro-thermal reaction; After naturally cooling to room temperature, centrifugal go out grey presoma, washing and alcohol wash several, centrifugal, dry, take out, Yong Yan ?be ground to Powdered after, proceed in semi-enclosed crucible, then be transferred in temperature programming tube furnace and calcine, after naturally cooling to room temperature, take out; Concrete grammar can with reference to Applied Catalysis B:Environmental 140 – 141 (2013) 141 – 150.

The temperature of described hydro-thermal reaction is 180 DEG C, and the reaction time is 20 h.

The calcining heat of described calcining grey presoma is 400 DEG C, and heating rate is 5 ^oc/min, calcination time is 4 h.

(2) β-Bi is taken ₂o ₃powder is dissolved in pure water, ultrasonic disperse, then adds AgNO ₃, magnetic agitation is to AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI solution, after magnetic agitation reaction, centrifugal, washing, alcohol wash for several times, is dried and is obtained described AgI/ β-Bi ₂o ₃composite; Granular AgI is deposited on sheet β-Bi ₂o ₃on.

Described ultrasonic disperse refers to adopt power to be ultrasonic 15-30 min in the ultrasonic machine of 250 W.

The time of described magnetic agitation is 25-40min.

The concentration of described KI solution is 0.01 molL ^-1.

The time of described magnetic agitation reaction is 3-5h.

Described AgI/ β-Bi ₂o ₃agI and β-Bi in composite ₂o ₃mass ratio be 0.05-0.4:1; Preferred 0.2:1.

Utilize X x ray diffractometer x (XRD), transmission electron microscope (TEM), micromorphology analysis is carried out to product, be that target dyestuff carries out photocatalytic degradation experiment with methyl orange (MO) solution, absorbance is measured, to assess its photocatalytic activity by ultraviolet-visible spectrophotometer.

Accompanying drawing explanation

Fig. 1 is prepared simple β-Bi ₂o ₃, AgI/ β-Bi ₂o ₃the XRD diffraction spectrogram of composite, simple AgI sample; As can be seen from the figure the AgI/ β-Bi of different quality ratio ₂o ₃xRD collection of illustrative plates primarily of AgI and β-Bi ₂o ₃diffraction maximum form, and along with AgI and β-Bi ₂o ₃the increase of proportioning, the diffraction maximum of AgI is more and more obvious.

Fig. 2 is prepared simple β-Bi ₂o ₃, AgI/ β-Bi ₂o ₃the transmission electron microscope photo of composite sample; As can be seen from the figure AgI is evengranular is dispersed in β-Bi ₂o ₃sheet surface; A ()-(f) is respectively the transmission electron microscope photo of embodiment 1-embodiment 6 product.

Fig. 3 is prepared simple β-Bi ₂o ₃, AgI/ β-Bi ₂o ₃the UV-Vis DRS abosrption spectrogram of composite, simple AgI sample, as can be seen from the figure AgI/ β-Bi ₂o ₃composite sample strengthens to some extent in the light absorption of visible region, and this is β-Bi in composite sample mainly ₂o ₃existence.

Fig. 4 be the composite photocatalytic degradation MO solution of different AgI content time m-degradation rate graph of a relation, as can be seen from the figure 20% AgI/ β-Bi ₂o ₃composite has the highest photocatalytic activity.

Detailed description of the invention

embodiment 1 sheet β-Bi ₂ o ₃ preparation

β-Bi ₂o ₃preparation adopts is the method for hydro-thermal reaction: take 4 mmol five water bismuth nitrates in 100 mL beakers, adding 5 mL glacial acetic acid is wherein stirred to entirely molten, add 35 mL absolute ethyl alcohols more wherein, stir 20 min, then gained settled solution being transferred to 50 mL liners is in the reactor of polytetrafluoroethylene (PTFE), put into baking oven, 180 DEG C of hydro-thermal reaction 20 h, after naturally cooling to room temperature, centrifugal go out grey presoma, washing and each three times of alcohol wash, centrifugal, 60 DEG C of vacuum drying 12 h in vacuum drying oven, take out, Yong Yan ?be ground to Powdered after, proceed in semi-enclosed crucible, then be transferred in temperature programming tube furnace, by temperature programming tube furnace with 5 ^othe heating rate of C/min is heated to 400 ^obe incubated 4 h after C, after naturally cooling to room temperature, take out.

embodiment 2 5% AgI/ β-Bi ₂ o ₃ the preparation of composite

AgI/ β-Bi ₂o ₃what the preparation of composite adopted is traditional water sedimentation method; Take 0.2 g β-Bi ₂o ₃powder is dissolved in 150 mL pure water, and then power is ultrasonic 20 min in the ultrasonic machine of 250 W, then adds AgNO ₃0.0076 g, magnetic agitation 0.5 h, AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI(0.01 molL ^-1) solution 4.48 mL, magnetic agitation reacts 4 h, and gained sample deionized water and absolute ethyl alcohol are respectively cleaned 3 times, in vacuum drying oven 60 ^οc vacuum drying 12 h, obtains 5% AgI/ β-Bi ₂o ₃composite.

embodiment 3 10% AgI/ β-Bi ₂ o ₃ the preparation of composite

AgI/ β-Bi ₂o ₃what the preparation of composite adopted is traditional water sedimentation method; Take 0.2 g β-Bi ₂o ₃powder is dissolved in 150 mL pure water, and then power is ultrasonic 20 min in the ultrasonic machine of 250 W, then adds AgNO ₃0.0161 g, magnetic agitation 0.5 h, AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI(0.01 molL ^-1) solution 9.47 mL, magnetic agitation reacts 4 h, and gained sample deionized water and absolute ethyl alcohol are respectively cleaned 3 times, in vacuum drying oven 60 ^οc vacuum drying 12 h, obtains 10% AgI/ β-Bi ₂o ₃composite.

embodiment 4 20% AgI/ β-Bi ₂ o ₃ the preparation of composite

AgI/ β-Bi ₂o ₃what the preparation of composite adopted is traditional water sedimentation method; Take 0.2 g β-Bi ₂o ₃powder is dissolved in 150 mL pure water, and then power is ultrasonic 20 min in the ultrasonic machine of 250 W, then adds AgNO ₃0.0362 g, magnetic agitation 0.5 h, AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI(0.01 molL ^-1) solution 21.30 mL, magnetic agitation reacts 4 h, and gained sample deionized water and absolute ethyl alcohol are respectively cleaned 3 times, in vacuum drying oven 60 ^οc vacuum drying 12 h, obtains 20% AgI/ β-Bi ₂o ₃composite.

embodiment 5 30% AgI/ β-Bi ₂ o ₃ the preparation of composite

AgI/ β-Bi ₂o ₃what the preparation of composite adopted is traditional water sedimentation method; Take 0.2 g β-Bi ₂o ₃powder is dissolved in 150 mL pure water, and then power is ultrasonic 20 min in the ultrasonic machine of 250 W, then adds AgNO ₃0.0620 g, magnetic agitation 0.5 h, AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI(0.01 molL ^-1) solution 36.51 mL, magnetic agitation reacts 4 h, and gained sample deionized water and absolute ethyl alcohol are respectively cleaned 3 times, in vacuum drying oven 60 ^οc vacuum drying 12 h, obtains 30% AgI/ β-Bi ₂o ₃composite.

embodiment 6 40% AgI/ β-Bi ₂ o ₃ the preparation of composite

AgI/ β-Bi ₂o ₃what the preparation of composite adopted is traditional water sedimentation method; Take 0.2 g β-Bi ₂o ₃powder is dissolved in 150 mL pure water, and then power is ultrasonic 20 min in the ultrasonic machine of 250 W, then adds AgNO ₃0.0965 g, magnetic agitation 0.5 h, AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI(0.01 molL ^-1) solution 56.79 mL, magnetic agitation reacts 4 h, and gained sample deionized water and absolute ethyl alcohol are respectively cleaned 3 times, in vacuum drying oven 60 ^οc vacuum drying 12 h, obtains 40% AgI/ β-Bi ₂o ₃composite.

embodiment 7 different proportion AgI/ β-Bi ₂ o ₃ the photocatalytic activity experiment of composite photo-catalyst

(1) compound concentration is the MO solution of 10 mg/L, and the solution prepared is placed in dark place.

(2) the AgI/ β-Bi of different quality ratio is taken ₂o ₃composite 0.03 g, is placed in photo catalysis reactor respectively, and add the target degradation solution that 60 mL steps (1) prepare, magnetic agitation 60 min treats AgI/ β-Bi ₂o ₃after composite is uniformly dispersed, open water source, light source, carry out photocatalytic degradation experiment.

(3) every 30 min draw the photocatalytic degradation liquid in reactor, for the measurement of UV-visible absorbance after centrifugal.

(4) 20% prepared as seen from Figure 4 AgI/ β-Bi ₂o ₃composite has excellent photocatalytic activity, especially 20% AgI/ β-Bi ₂o ₃sample MO solution degradation rate after catalytic reaction 240 min reach 100 %.

Claims

1. a preparation method for silver iodide/β type bismuth oxide composite, AgI is evengranular is dispersed in β-Bi ₂o ₃sheet surface, is characterized in that: take β-Bi ₂o ₃powder is dissolved in pure water, ultrasonic disperse, then adds AgNO ₃, magnetic agitation is to AgNO ₃after dissolving completely, under lucifuge condition, be added dropwise to KI solution, after magnetic agitation reaction, centrifugal, washing, alcohol wash for several times, is dried and is obtained described AgI/ β-Bi ₂o ₃composite; Granular AgI is deposited on sheet β-Bi ₂o ₃on.

2. the preparation method of a kind of silver iodide as claimed in claim 1/β type bismuth oxide composite, is characterized in that: described ultrasonic disperse refers to adopt power to be ultrasonic 15-30 min in the ultrasonic machine of 250 W.

3. the preparation method of a kind of silver iodide as claimed in claim 1/β type bismuth oxide composite, is characterized in that: the time of described magnetic agitation is 25-40min.

4. the preparation method of a kind of silver iodide as claimed in claim 1/β type bismuth oxide composite, is characterized in that: the concentration of described KI solution is 0.01 molL ^-1.

5. the preparation method of a kind of silver iodide as claimed in claim 1/β type bismuth oxide composite, is characterized in that: the time of described magnetic agitation reaction is 3-5h.

6. the preparation method of a kind of silver iodide as claimed in claim 1/β type bismuth oxide composite, is characterized in that: described AgI/ β-Bi ₂o ₃agI and β-Bi in composite ₂o ₃mass ratio be 0.05-0.4:1.

7. the preparation method of a kind of silver iodide as claimed in claim 6/β type bismuth oxide composite, is characterized in that: described AgI/ β-Bi ₂o ₃agI and β-Bi in composite ₂o ₃mass ratio be 0.2:1.