CN103418415A

CN103418415A - Method for using ultrasonic mixing to prepare Ag-g-C3N4/TiO2 photocatalyst

Info

Publication number: CN103418415A
Application number: CN2013103688095A
Authority: CN
Inventors: 吴小琴; 柳泽斌; 夏冬冬; 陈天泽
Original assignee: Nanchang Hangkong University
Current assignee: Nanchang Hangkong University
Priority date: 2013-08-22
Filing date: 2013-08-22
Publication date: 2013-12-04

Abstract

A method for using ultrasonic mixing to prepare Ag-g-C3N4/TiO2 photocatalyst is characterized by including: heating reagent melamine to 540 DEG C to allow the same to split into g-C3N4; using ultrasonic mixing to allow P25 to load the g-C3N4; using solidifying sol process and silver-mixed synthesis to prepare the Ag-g-C3N4/TiO2 photocatalyst. Due to the fact that the Ag-g-C3N4/TiO2 photocatalyst is high in visible light activity, the photocatalyst can be served as a significant waste water processing agent with potential research value. The method is simple in reaction condition, mild and stable in reaction, and easy in mass production.

Description

Prepare Ag-g-C by ultrasonic mixing method 3N 4/ TiO 2The method of photochemical catalyst

Technical field

The present invention relates to a kind of preparation method of visible-light photocatalyst, relate in particular to the ultrasonic mixing method of a kind of use and prepare Ag-g-C ₃N ₄ /TiO ₂The method of photochemical catalyst.

Background technology

Ag-g-C ₃N ₄ /TiO ₂The ternary visible photochemical catalyst, because of the composite photo-catalyst tool visible light activity containing this structure, thereby become a kind of important sewage-treating agent with potential researching value.More to the research of binary composite photo-catalyst both at home and abroad, but preparation Ag-g-C not yet appears ₃N ₄ /TiO ₂The report of tri compound photochemical catalyst.Therefore without the complete preparation method who synthesizes this tri compound photochemical catalyst; For this fact, the present invention has at length set forth whole preparation technology: take melamine as raw material, finally made target product by Pintsch process, ultrasonic mixing, immobilization collosol craft successively.

Summary of the invention

The object of the present invention is to provide the ultrasonic mixing method of a kind of use to prepare Ag-g-C ₃N ₄ /TiO ₂The method of photochemical catalyst, this preparation method has finally made target product Ag-g-C by Pintsch process, ultrasonic mixing, immobilization collosol craft successively ₃N ₄ /TiO ₂Tri compound high-performance optical catalyst.

The present invention is achieved like this, and it is characterized in that the preparation method is:

1, take appropriate melamine in porcelain crucible, be placed in Muffle furnace, by room temperature, rise to temperature 540 ^oC, and after constant temperature 2 h, cooling naturally.Take out after being cooled to room temperature, after weighing, sample is ground into powder and obtains light yellow photochemical catalyst g-C ₃N ₄.

2, at first press load capacity (2%, 4%, 8%, 10%) by a certain amount of g-C ₃N ₄Powder joins P25(TiO ₂) ethanol solution in, then ultrasonic water bath 15 min disperse fully to powder.80 ^oC vacuum drying 5 h evaporates to dryness obtain powder, after grinding in Muffle furnace 400 ^oCalcining 2 h under the C condition.Naturally cooling.Take out after being cooled to room temperature, after having claimed, sample is ground into powder, obtain binary composite photo-catalyst g-C ₃N ₄ /TiO ₂.

3, collargol passes through NaBH ₄Make reducing agent oxidation AgNO ₃And obtain, and make protective agent to reach dispersed preferably with polyvinyl alcohol (PVA).

Detailed process is as follows: get 8 mL AgNO ₃The aqueous solution (Ag content is 1.60 mgmL ^-1I.e. 12.8 mg, 0.1187 mmol Ag), in ice-water bath, with protective agent PVA (getting 8.5 mg PVA is dissolved in 8.0 ml water), mix ( m _Ag: m _PVA=1.5:1) and vigorous stirring, then add fast NaBH ₄The aqueous solution, Ag and NaBH ₄Mol ratio be 1:5.NaBH ₄Aqueous solution preparation: by 22.45 mg NaBH ₄Be dissolved in 9.60 mL water, when colloidal sol, from the colourless black that becomes, show that silver sol forms.Under ultrasonic cavitation and stirring, by load capacity m _Ag: m _TiO2=1.0% left and right is carrier g-C ₃N ₄/ TiO ₂Join in silver sol suspension, keep both to contact until all absorb, obtain target product Ag-g-C ₃N ₄ /TiO ₂, then wet solid catalyst is placed in to 80 ° of C drying boxes dry.Put afterwards in drier and be cooled to room temperature, the rear preservation of weighing, obtain tri compound photochemical catalyst Ag-g-C ₃N ₄ /TiO ₂.

Advantage of the present invention is: reaction condition is simple, reaction temperature and and stable, be easy to amplify and produce.

The accompanying drawing explanation

The UV-vis DRS spectrum that Fig. 1 is embodiment of the present invention gained sample.

The visible light activity that Fig. 2 is different photochemical catalysts of the present invention.

The specific embodiment

1. melamine pyrolysis prepares g-C ₃N ₄

Take 3 g melamines and be placed in 50 mL porcelain crucibles, put into Muffle furnace, by room temperature, rise to temperature 540 ^oC, after constant temperature 2 h, cooling naturally.Take out after being cooled to room temperature, obtain g-C ₃N ₄, after weighing, by the sample preservation that is ground into powder.

2. the ultrasonic g-C that is mixed with ₃N ₄ /TiO ₂

Take respectively 0.10 gTiO ₂Four parts of pressed powders are placed in four 100 mL beakers, respectively add ethanol solution 50 mL, then add respectively the g-C of 0.002 g, 0.004 g, 0.008 g, 0.01 g ₃N ₄Powder, obtain g-C ₃N ₄ /TiO ₂Mass ratio is respectively: 2%, 4%, 8%, 10%.Then ultrasonic mixing 15 min disperse fully to powder.80 ^oC is dry, and 5 h obtain powder with evaporate to dryness, are placed in Muffle furnace 400 after grinding ^oCalcining 2 h under the C condition.Naturally cooling.After being cooled to room temperature, take out, after having claimed, by the sample preservation that is ground into powder.

3, fixedly solation technique prepares target product Ag-g-C ₃N ₄ /TiO ₂

Detailed process is as follows: the AgNO that gets 8 mL ₃(Ag content is 1.60 mgmL to the aqueous solution ^-1, i.e. 12.8 mg, 0.1187 mmol Ag), in ice-water bath, with protective agent PVA (getting 8.6 mg PVA is dissolved in 8.0 ml water), mix ( m _Ag: m _PVA=1.5:1) and vigorous stirring, then add fast NaBH ₄The aqueous solution (22.45 mg NaBH ₄Be dissolved in 9.60 mL water) ( n _Ag: n _NaBH4=1:5), from the colourless black that becomes, show that silver sol forms when colloidal sol.Under ultrasonic cavitation and stirring, by load capacity m _Ag: m _G-C3N4/TiO2=0.5,1.0,1.5,2.0,3.0% carrier g-C ₃N ₄ /TiO ₂Join in silver sol suspension, keep both to contact until all absorb, obtain target product Ag-g-C ₃N ₄ /TiO ₂.Then wet solid catalyst is placed in to 80 ° of C drying boxes dry.Put afterwards in drier and be cooled to room temperature, the rear preservation of weighing.

4, photochemical catalyst characterizes and the photocatalysis performance test

As shown in Figure 1 and Figure 2, with UV-Vis DRS spectrum, the photochemical catalyst sample is characterized, and (it is 10 mg that 100 mg catalyst add 100 mL concentration to have measured the ability of photocatalyst for degrading methylene blue (MB) /In the MB of L, under the lucifuge stirring condition, absorption 2 h, add afterwards 420 nm optical filters, then irradiate 4 h with 500 W xenon lamps).

Claims

1. prepare Ag-g-C by ultrasonic mixing method ₃N ₄ /TiO ₂The method of photochemical catalyst, is characterized in that multistep is synthetic, and concrete steps are:

(1) photochemical catalyst g-C ₃N ₄Preparation:

Take 3 g melamines in porcelain crucible, be placed in Muffle furnace, by room temperature, rise to temperature 540 ^oC, and after constant temperature 2 h, cooling naturally, take out after being cooled to room temperature, obtains sodium yellow catalyst g-C ₃N ₄, after weighing, by the sample preservation that is ground into powder;

(2) binary composite photo-catalyst g-C ₃N ₄ /TiO ₂Preparation:

Take respectively 0.1 gTiO ₂Four parts of pressed powders are placed in four 100 mL beakers, respectively add ethanol solution 50 mL, then add respectively the g-C of 0.002 g, 0.004 g, 0.008 g, 0.01 g ₃N ₄Powder, obtain g-C ₃N ₄/ TiO ₂Mass ratio is respectively: 2%, 4%, 8%, 10%, and then distinguish ultrasonic mixing 15 min and disperse fully to powder, 80 ^oC is dry, and 5 h obtain powder with evaporate to dryness, are placed in Muffle furnace 400 after grinding ^oUnder the C condition, calcining 2 h, lower the temperature naturally, takes out after being cooled to room temperature, after having claimed, by the sample preservation that is ground into powder;

(3) fixedly solation technique prepares target product Ag-g-C ₃N ₄ /TiO ₂:

Get the g-C that mass ratio is 8% ₃N ₄ /TiO ₂Binary composite catalyst is done carrier, and collargol passes through NaBH ₄Make reducing agent oxidation AgNO ₃And obtain, and make protective agent to reach dispersed preferably with polyvinyl alcohol; Detailed process is as follows: getting 8 mL concentration is 1.60 mgmL ^-1AgNO ₃The aqueous solution mixes with protective agent PVA solution in ice-water bath, and the solution ratio is m _Ag: m _PVA=1.5:1, vigorous stirring, then add Ag and NaBH fast ₄The mol ratio NaBH that is 1:5 ₄The aqueous solution, from the colourless black that becomes, show that silver sol forms when colloidal sol, under ultrasonic cavitation and stirring, presses load capacity g-C ₃N ₄/ TiO ₂Carrier joins in silver sol suspension, keeps both to contact until all absorb, and the load capacity of silver in carrier is 0.5,1.0,1.5,2.0, and 3.0 wt %, obtain target product Ag-g-C like this ₃N ₄ /TiO ₂Ternary complex, then be placed in 80 ° of dry 5 h of C drying box to wet target product, is placed in afterwards drier and is cooled to room temperature, the rear preservation of weighing.