CN104532479B - A kind of photocatalytic fiber cellulose fiber matrix activated carbon nano-fiber composite film and preparation method thereof - Google Patents

Abstract

The invention provides a kind of photocatalytic fiber cellulose fiber matrix activated carbon nano-fiber composite film and preparation method thereof, first faint yellow TiO is made in butyl titanate by this method₂Vitreosol, then be added in the cellulose fibre solution prepared, it is fully reacted, stir transparent to solution, TiO is made by electrostatic spinning in mixing₂/ cellulosic fibrous substrates composite nano-fiber membrane.Composite nano-fiber membrane is prepared into the photocatalytic fiber cellulose fiber matrix activated carbon nano-fiber composite film with efficient absorption and catalytic performance through pre-oxidation, charing and activation process again.Preparation method process of the present invention is simple, and obtaining photocatalytic fiber cellulose fiber matrix activated carbon nano-fiber composite film has stronger absorption property and preferable Photocatalytic Degradation Property, and has the advantages that to be catalyzed in waste water or organic pollution in air.

Description

A photocatalytic cellulose fiber-based activated carbon nanofiber composite film and its preparation method

technical field

The invention relates to a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane and a preparation method thereof, belonging to the preparation technology of activated carbon composite materials.

Background technique

Traditional printing and dyeing wastewater treatment methods are not ideal, mainly because the molecular structure of dyes in wastewater is stable, the composition is complex, the decolorization rate and COD removal rate are not high, and secondary pollution is easy to occur. Using the photocatalytic properties of semiconductor materials, many organic substances that cannot be removed by chemical and biological methods can be completely decomposed into carbon dioxide and water at room temperature without causing secondary pollution. It can be used as sunlight and ultraviolet light contained in fluorescent lamps. excitation source. At present, among the catalysts used to degrade environmental pollutants, titanium dioxide has become one of the most promising photocatalysts due to its high photocatalytic activity, insoluble, non-toxic and low cost, and has the ability to purify air, kill bacteria, Degradation of refractory organic matter, etc. However, the traditional nano-TiO ₂ suspension phase photocatalysts are prone to deactivation, aggregation, and difficult to recycle. Therefore, finding a high-efficiency loading material with a large specific surface area and a strong combination with TiO ₂ is the key to practical technology. Activated carbon material, as an ideal adsorption material, is developed on the basis of the combination of carbon fiber technology and activated carbon technology. Activated carbon has a large pore volume and specific surface area, and is dominated by micropores. Therefore, it is conducive to the diffusion of adsorbate into the pores and the active surface. Activated carbon shows higher adsorption capacity and faster adsorption and desorption speed. The activated carbon will effectively absorb and remove dyes, pastes, additives, oil agents, acids and bases, fiber impurities, inorganic salts, etc. in sewage.

Since printing and dyeing wastewater often contains high suspended solids and organic substances such as pigments, any single technology treatment often fails to achieve the desired effect. At present, the integrated process research of membrane separation technology and other water treatment technologies takes advantage of various technologies to form a new process for the advanced treatment of printing and dyeing wastewater. Countries with developed economies and advanced science and technology in the world have applied membrane separation technologies such as ultrafiltration (UF), reverse osmosis (RO) and nanofiltration (NF) to the treatment of printing and dyeing industrial wastewater in recent years, which can greatly reduce energy consumption. Reduce investment. Due to the advantages of high separation efficiency, energy saving, simple equipment and convenient operation, membrane filtration technology has great development potential in the field of wastewater treatment. However, at present, there is more or less a fouling problem in the sewage treatment process of MF and UF membranes, and sometimes this problem is very serious, resulting in a serious drop in water yield, which directly affects the operating efficiency of the system and its success or failure. Utilizing the special surface chemical structure and strong physical adsorption of activated carbon fibers, it provides a high-concentration reaction environment for TiO ₂ photocatalysis, effectively removes organic pollutants in water with its synergistic effect of adsorption and catalysis, and greatly improves the reuse rate of printing and dyeing wastewater . The recycling of printing and dyeing wastewater through photocatalytic activated carbon nanofiber membranes has very positive significance for the control of water pollution and the sustainable development of the printing and dyeing industry.

Contents of the invention

In order to overcome the above-mentioned deficiencies in the prior art, the present invention aims to provide a photocatalyzed cellulose fiber-based activated carbon nanofiber composite membrane and a preparation method thereof. The composite material obtained by this method has stronger adsorption properties and better Photocatalytic degradation performance.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A preparation method of photocatalyzed cellulose fiber-based activated carbon nanofiber composite film. In this method, tetrabutyl titanate is first made into light yellow _TiO2 transparent sol, and then added to the prepared cellulose fiber solution, continuously Stir to make it fully react until the solution is transparent, and the mixed solution is electrospun to obtain a TiO ₂ /cellulose fiber-based composite nanofiber membrane; then the TiO ₂ /cellulose fiber-based composite nanofiber membrane is pre-oxidized, carbonized and The activation process is prepared into a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane with high-efficiency adsorption and catalytic performance; the method includes the following steps:

1) Titanium dioxide sol preparation: dissolve 15-30 parts of tetrabutyl titanate and 5-15 parts of glacial acetic acid in 50-80 parts of absolute ethanol, stir magnetically for 0.5-2 hours to mix evenly, slowly drop into 80-95 part of absolute ethanol and 5-20 parts of distilled water, control the dripping speed of the burette, seal and stir to obtain a light yellow _TiO2 transparent sol, and let it stand for 2-4 hours;

2) Preparation of cellulose fiber solution: dissolve cellulose fiber in a corresponding solvent at room temperature, prepare a solution with a volume mass fraction (g/L) of 1-20%, and magnetically stir until the solution is transparent;

3) Preparation of cellulose fiber-based composite nanofiber membrane: mix the titanium dioxide solution prepared in step 1) with the cellulose fiber solution prepared in step 2) according to the mass ratio of solutes of 0.01:1 to 0.5:1, and react fully. Stir until it is completely mixed and the solution is transparent, and the TiO ₂ /cellulose fiber-based composite nanofiber film is prepared by an electrospinning device;

4) Preparation of activated carbon composite nanofiber membrane: the TiO2/cellulose fiber-based composite nanofiber membrane prepared in step 3) is pre-oxidized, carbonized and activated to prepare a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane.

The cellulose fiber material is natural cellulose fiber and regenerated cellulose fiber, natural cellulose fiber includes hemp fiber, bamboo fiber, cotton; regenerated cellulose fiber includes viscose fiber, Tencel fiber, Lyocell fiber, Modal fiber.

Described step 2) the used solvent of cellulose fiber is dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methylmorpholine-N-oxide compound, tetraethylammonium chloride solution, One or more mixed solvent systems in ammonium thiocyanate solution, triethanolamine, ammonia solution, and alkaline aqueous solution.

The alkaline aqueous solution is an aqueous alkali metal hydroxide solution, specifically sodium hydroxide and potassium hydroxide.

The electrostatic spinning device is composed of a high voltage generator, a syringe pump and a fiber receiver; the spinning voltage: 10-30kV, the extrusion rate: 0.05-2.0ML/h, and the receiving distance: 10-30cm.

The pre-oxidation temperature is controlled at 50-350° C.; the activation is carried out in a 5-20 wt % H ₃ PO ₄ solution and a 5-20 wt % KOH solution; carbonization is carried out in a tubular muffle furnace in an inert gas atmosphere ( For example, N ₂ , etc.), the temperature is controlled at 400-600°C for calcining to obtain the TiO ₂ crystal form with catalytic activity.

The inert gas is nitrogen, argon.

The invention also includes the photocatalytic cellulose fiber-based activated carbon nanofiber composite film prepared by the above method.

The preparation method of the invention has a simple process, and the obtained photocatalytic cellulose fiber-based activated carbon nanofiber composite film has strong adsorption performance and good photocatalytic degradation performance.

detailed description

The present invention will be further described below in conjunction with specific embodiments.

A preparation method of photocatalyzed cellulose fiber-based activated carbon nanofiber composite film. In this method, tetrabutyl titanate is first made into light yellow _TiO2 transparent sol, and then added to the prepared cellulose fiber solution, continuously Stir to make it fully react until the solution is transparent, and the mixed solution is electrospun to obtain a TiO ₂ /cellulose fiber-based composite nanofiber membrane; then the TiO ₂ /cellulose fiber-based composite nanofiber membrane is pre-oxidized, carbonized and Through the activation process, a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane with high-efficiency adsorption and catalytic performance is prepared; the preparation method of the present invention is simple, and the obtained photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane has strong adsorption performance and good photocatalytic degradation performance.

Example 1:

A preparation method of a photocatalytic cellulose fiber-based activated carbon nanofiber composite film, the method comprising the following steps:

1) Titanium dioxide sol preparation: Dissolve 15 parts of tetrabutyl titanate and 5 parts of glacial acetic acid in 50 parts of absolute ethanol, stir magnetically for 0.5 h to make them evenly mixed, and slowly drop into a mixture of 80 parts of absolute ethanol and 5 parts of distilled water In the mixed solution, control the dropping speed of the burette, seal and stir to obtain a light yellow _TiO transparent sol, and leave it to age for 2 hours;

2) Preparation of cellulose fiber solution: dissolve cellulose fiber (hemp fiber) in dimethyl sulfoxide at room temperature, prepare a solution with a volume mass fraction (g/L) of 1%, and stir magnetically until the solution is transparent;

3) Preparation of cellulose fiber-based composite nanofiber membrane: mix the titanium dioxide solution prepared in step 1) with the cellulose fiber solution prepared in step 2) according to the solute mass ratio of 0.01:1, fully react, and stir until completely mixed Uniform and transparent solution, TiO ₂ /cellulose fiber-based composite nanofiber membrane was prepared by electrospinning device;

4) Preparation of activated carbon composite nanofiber membrane: the TiO2/cellulose fiber-based composite nanofiber membrane prepared in step 3) is pre-oxidized, carbonized and activated, the pre-oxidation temperature is 150 ° C, and the H ₃ PO ₄ solution and 5wt% KOH solution; in a tubular muffle furnace, carbonization was carried out in an inert gas N ₂ atmosphere, and the temperature was controlled at 450 ° C for calcination to prepare a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane.

Example 2:

A preparation method of a photocatalytic cellulose fiber-based activated carbon nanofiber composite film, the method comprising the following steps:

1) Titanium dioxide sol preparation: Dissolve 20 parts of tetrabutyl titanate and 10 parts of glacial acetic acid in 60 parts of absolute ethanol, stir for 1 hour to make it evenly mixed, and slowly drop in a mixture of 85 parts of absolute ethanol and 10 parts of distilled water In the solution, control the drip rate of the burette, seal and stir to obtain a light yellow _TiO transparent sol, and leave it to age for 3h;

2) Preparation of cellulose fiber solution: dissolve cellulose fiber (Lyocell fiber) in dimethylformamide at room temperature, prepare a solution with a volume mass fraction (g/L) of 8%, and magnetically stir until the solution is transparent;

3) Preparation of cellulose fiber-based composite nanofiber membrane: mix the titanium dioxide solution prepared in step 1) with the cellulose fiber solution prepared in step 2) according to the solute mass ratio of 0.1:1, fully react, and stir until completely mixed Uniform and transparent solution, TiO ₂ /cellulose fiber-based composite nanofiber membrane was prepared by electrospinning device;

4) Preparation of activated carbon composite nanofiber membrane: the TiO2/cellulose fiber-based composite nanofiber membrane prepared in step ₃ ) is subjected to pre-oxidation, carbonization and activation processes. _The pre-oxidation temperature is 180° C. solution and 10wt% KOH solution for activation; in a tubular muffle furnace, carbonization is carried out in an inert gas (argon) atmosphere, and the temperature is controlled at 450 ° C for calcination to prepare a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane .

Example 3:

A preparation method of a photocatalytic cellulose fiber-based activated carbon nanofiber composite film, the method comprising the following steps:

1) Titanium dioxide sol preparation: Dissolve 25 parts of tetrabutyl titanate and 15 parts of glacial acetic acid in 70 parts of absolute ethanol, stir for 1.5 hours with magnetic force to make it evenly mixed, slowly drop into a mixture of 90 parts of absolute ethanol and 15 parts of distilled water In the mixed solution, control the dripping speed of the burette, seal and stir to obtain a light yellow _TiO transparent sol, and leave it to age for 3 hours;

2) Preparation of cellulose fiber solution: Dissolve cellulose fiber (Modal fiber) in N-methylmorpholine-N-oxide at room temperature, and prepare a solution with a volume mass fraction (g/L) of 15%, Stir magnetically until the solution is transparent;

3) Preparation of cellulose fiber-based composite nanofiber membrane: mix the titanium dioxide solution prepared in step 1) with the cellulose fiber solution prepared in step 2) according to the solute mass ratio of 0.3:1, fully react, and stir until completely mixed Uniform and transparent solution, TiO ₂ /cellulose fiber-based composite nanofiber membrane was prepared by electrospinning device;

4) Preparation of activated carbon composite nanofiber membrane: the TiO2/cellulose fiber-based composite nanofiber membrane prepared in step 3) is subjected to pre-oxidation, carbonization and activation processes, the pre-oxidation temperature is 200 ° C, and the H ₃ PO ₄ solution and 15wt% KOH solution; in a tubular muffle furnace, carbonization was carried out in an inert gas N ₂ atmosphere, and the temperature was controlled at 500 ° C for calcination to prepare a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane.

Example 4:

A preparation method of a photocatalytic cellulose fiber-based activated carbon nanofiber composite film, the method comprising the following steps:

1) Titanium dioxide sol preparation: Dissolve 30 parts of tetrabutyl titanate and 15 parts of glacial acetic acid in 80 parts of absolute ethanol, stir magnetically for 2 hours to make it evenly mixed, slowly drop in a mixture of 95 parts of absolute ethanol and 20 parts of distilled water In the solution, control the drip rate of the burette, seal and stir to obtain a light yellow _TiO transparent sol, and leave it to age for 4h;

2) Preparation of cellulose fiber solution: Dissolve cellulose fiber (bamboo fiber) in ammonia/ammonium thiocyanate solution (NH ₃ /NH ₄ SCN/H ₂ O system) at room temperature, and prepare the volume mass fraction (g /L) is 8% solution, magnetically stirred until the solution is transparent;

3) Preparation of cellulose fiber-based composite nanofiber membrane: mix the titanium dioxide solution prepared in step 1) with the cellulose fiber solution prepared in step 2) according to the solute mass ratio of 0.5:1, fully react, and stir until completely mixed Uniform and transparent solution, TiO ₂ /cellulose fiber-based composite nanofiber membrane was prepared by electrospinning device;

4) Preparation of activated carbon composite nanofiber membrane: the TiO ₂ /cellulose fiber-based composite nanofiber membrane prepared in step 3) is pre-oxidized, carbonized and activated, the pre-oxidation temperature is 250 ° C, and the H ₃ PO ₄ solution and 20wt% KOH solution for activation; in a tubular muffle furnace, carbonization is carried out in an inert gas (argon) atmosphere, and the temperature is controlled at 550 ° C for calcination to prepare a photocatalytic cellulose fiber-based activated carbon nanofiber composite membrane.

Claims (1)

1. a kind of preparation method of photocatalytic fiber cellulose fiber matrix activated carbon nano-fiber composite film, this method is first by metatitanic acid four Faint yellow TiO is made in butyl ester₂Vitreosol, then be added in the cellulose fibre solution prepared, Being stirred continuously makes it fully react, transparent to solution, and mixed liquor is made into TiO by electrostatic spinning₂/ fine Cellulose fiber based composite nano fiber film；Again by TiO₂/ cellulosic fibrous substrates composite nano-fiber membrane is through pre- Oxidation, charing and activation process, are prepared into the photocatalytic fiber cellulose fiber matrix activated carbon with efficient absorption and catalytic performance and receive Rice composite fiber membrane；This method comprises the following steps：

1) prepared by TiO 2 sol：15~30 parts of butyl titanates and 5~15 parts of glacial acetic acid are dissolved in 50~80 parts of anhydrous second In alcohol, the h of magnetic agitation 0.5~2 is allowed to well mixed, is slowly dropped into the mixed of 80~95 parts of absolute ethyl alcohols and 5~20 parts of distilled water Close in solution, control buret drop speed, sealing stirring obtains faint yellow TiO₂Vitreosol, still aging 2 ~4h；

2) prepared by cellulose fibre solution：Cellulose fibre is dissolved in corresponding solvent at room temperature, volume matter is configured to The solution that fraction is 1~20%g/L is measured, magnetic agitation is transparent to solution；The cellulosic fibre material is that native cellulose is fine Peacekeeping regenerated celulose fibre, native cellulose fibre includes flaxen fiber, bamboo fibre, cotton；Regenerated celulose fibre includes viscous Glue fiber, Tencel fibers, Lyocell fiber, Modal fibers；Solvent is dimethyl sulfoxide (DMSO), dimethyl acetamide, N- methyl One in methylmorpholine-N-oxide, etamon chloride solution, ammonium thiocyanate solution, triethanolamine, ammonia spirit, alkaline aqueous solution Plant or several mixed solvent systems；Alkaline aqueous solution is alkali metal hydroxide aqueous solution, specially sodium hydroxide, hydroxide Potassium；

3) prepared by cellulosic fibrous substrates composite nano-fiber membrane：By step 1) made from TiO 2 sol and step 2) system The cellulose fibre solution obtained is mixed according to the mass ratio 0.01: 1~0.5: 1 of solute, fully reaction, is stirred to completely mixed Close uniformly and solution is transparent, pass through electrostatic spinning apparatus and TiO is made₂/ cellulose fibre based composite nano fiber Film；Described electrostatic spinning apparatus is made up of high-voltage generator, syringe pump and fiber receiver；Spinning voltage：10~30 KV, rate of extrusion：0.05~2.0ML/h, receives distance：10~30 cm；

4) prepared by activated carbon composite nano-fiber membrane：By step 3) made from TiO₂/ cellulosic fibrous substrates are multiple Nano fibrous membrane is closed through pre-oxidation, charing and activation process, photocatalytic fiber cellulose fiber matrix activated carbon nanofiber is prepared into and answers Close film；Described Pre oxidation is controlled at 50~350 DEG C；Activation is the H in 5~20wt%₃PO₄Carried out in solution and 5~20wt% KOH solution；Charing is in tubular type Muffle furnace, in atmosphere of inert gases, temperature control 400~600 DEG C of calcination of system, to obtain the TiO with catalytic activity₂Crystal formation；The inert gas be nitrogen, Argon gas.