CN109989273A - A kind of preparation method and application of photocatalytic coating fabric - Google Patents

Abstract

The invention discloses a preparation method and application of a visible light catalytic coated fabric. The method selects chlorine-rich chloroprene rubber as a binder, first coats it on the surface of the fabric, and then sprays photocatalyst titanium dioxide onto the surface of the fabric. The surface of the fabric is coated with an adhesive to stabilize the photocatalyst on the surface of the fabric. As an adhesive, neoprene rubber can not only stably fix titanium dioxide on the surface of the fabric, but also dechlorinate the neoprene rubber. At the same time, chloride ions can modify titanium dioxide, and part of the chloride ions can be stably adsorbed on the surface of titanium dioxide, which significantly changes the surface charge of titanium dioxide. It promotes the negative charge on the surface of titanium dioxide, and has better adsorption to cationic dyes and thus has better degradation performance. Part of the chlorine will enter the titania lattice to replace the lattice oxygen, causing titania to generate oxygen defects, reducing the titania band gap and enhancing titania's absorption of visible light, thereby improving the visible light catalytic degradation performance of titania.

Description

A kind of preparation method and application of photocatalytic coating fabric

technical field

The invention belongs to the field of functional fabric preparation and surface modification, and relates to a preparation method of a functional fabric surface modified and supported photocatalyst. The coated fabric is used for photocatalytic degradation of printing and dyeing wastewater and other pollutants in water bodies.

Background technique

With the rapid development of modern social industry, the problem of environmental pollution is becoming more and more serious. Various water pollution, such as organic dyes from factories, wastewater from synthetic coatings, plastics, tanning, textile processes, etc. In particular, dyes containing aromatic molecular structures generally have good photostability and thermal stability. If these dye wastewater cannot be effectively treated, it will seriously damage the ecological environment and even threaten human health. Therefore, the efficient removal of dyes from wastewater is very important. There are many methods for treating dye-containing wastewater, and currently there are adsorption, flocculation, electrolysis, biodegradation and photocatalytic degradation. Among them, the adsorption method can remove dyes from wastewater very well, but it cannot fundamentally solve the harm of dyes to the environment. Because adsorption only separates dyes from wastewater, it does not decompose dyes into environmentally friendly substances.

Photocatalytic pollutant degradation technology is a recently developed effective means of treating pollutants. It uses ultraviolet light or even sunlight as an energy source to stimulate semiconductor catalysts to generate strong oxidative free radicals, which can successfully degrade most organic compounds in water. . It has low operating cost, is a high-efficiency energy-saving technology, and has good application prospects. _TiO2 photocatalyst has been widely used at present, it has the advantages of high chemical stability, non-toxic and harmless, low cost, high activity and so on. However, it has shortcomings such as wide band gap, low quantum yield, weak adsorption capacity for pollutants, small solid powder particles and easy agglomeration. In addition, _TiO2 photocatalysis does not absorb visible light and after the degradation of pollutants is completed, the nanophotocatalysts cannot be recycled, limiting their applicability in real water treatment systems. Therefore, it is very important to improve the absorption of visible light by _TiO2 by modifying _TiO2 and to realize the recycling of the catalyst on the solid support of _TiO2 photocatalyst. The textile fabric as a support can increase the availability of nano-photocatalysts, which can improve the contact area between the catalyst and pollutants, and the textile fabric has durability. In addition, the modification of nanophotocatalysts can increase the adsorption of dyes by the catalysts.

The study designers cured _TiO2 and Fe-C- _TiO2 photocatalysts on cotton materials, mixed sodium silicate with nanophotocatalysts and then coated them on cotton fabrics. Then the functionalized cotton material was inserted into a flow photocatalytic reactor for phenol decomposition (Hazard. Mater. 151 (2008) 62-64). This method has certain defects. After the photocatalyst is mixed with the binder, the surface is covered with sodium silicate binder, which has poor light absorption effect, and the sodium silicate adhesion is not very strong. photocatalytic activity.

Tian Xingyou et al. constructed an easily recyclable _TiO2 /potassium alginate-CNTs photocatalyst coating on cotton fabrics through a layer-by-layer self-assembly technique. Nanocoatings exhibit excellent catalytic performance for formaldehyde and rhodamine B (RhB) under simulated sunlight irradiation (Xingyou Tian.et.al.Cellulose (2017) 24:4569–4580), but the self-assembly method is complicated and unsuitable Mass production preparation. The present invention selects chloroprene rubber with high bonding strength, good stability, acid and alkali resistance, and chlorine-rich as the adhesive, and disperses and loads the titanium dioxide on the surface of the fabric by simply coating the surface of the fabric and spraying the titanium dioxide suspension. The modification of titanium dioxide by chlorine is realized, and the photocatalytic effect of titanium dioxide is improved. The method is easy to operate, low in cost, and can be used for large-scale production of photocatalytic coated fabrics, and has a good application in the field of printing and dyeing wastewater degradation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a photocatalytic coated fabric, which is used for photocatalytic degradation of printing and dyeing wastewater and other pollutants in water bodies.

The present invention selects chlorine-rich chloroprene rubber as the adhesive, first coats it on the surface of the fabric, and then sprays the photocatalyst titanium dioxide on the surface of the fabric coated with the adhesive to stabilize the photocatalyst on the surface of the fabric, The neoprene adhesive also has a modification effect on titanium dioxide, so that the degradation performance of titanium dioxide on dyes is enhanced.

The preparation method of above-mentioned photocatalytic coating fabric, concrete preparation steps are as follows:

A. Add ethanol and acetone into the container at a ratio of 1:1 and mix them evenly to obtain a mixed solution. Cut the selected fabric into a suitable size according to the needs of use, soak it in the above mixed solution, and ultrasonically clean the fabric for 60-100min. Then dry the fabric at 60-80 ° C; the fabric is a material with a thickness of 2-4mm, porous, and a surface area of 10-30m ² /g, including flumes, acrylic filter material, coral fleece, double Velvet, etc.

B. Add titanium dioxide into absolute ethanol, stir for 10-30min and then ultrasonicate for 1-3h to completely disperse titanium dioxide in ethanol to obtain a titanium dioxide suspension, wherein the concentration of titanium dioxide is 2.5-10g/L. The titanium dioxide is commercial titanium dioxide with a model of P25 (P25 for short), and its crystal form is a mixed crystal form consisting of anatase type and rutile type in a ratio of 4:1.

C. Dissolve the neoprene in xylene and stir until it is completely dissolved, wherein the neoprene concentration is 80-280 g/L, and then evenly coat it on both sides of the fabric described in step A.

D. Add the titanium dioxide suspension of step B into the high-pressure spray gun, shake well, spray evenly on both sides of the fabric before the neoprene rubber on the surface of the fabric in step C is dry, and dry it at 50-90 ° C or dry it at room temperature, i.e. The double-sided titanium dioxide-supported coated fabric was obtained; the photocatalytic coated fabric was obtained by aging at room temperature for 96-168 h.

In the present invention, nanometer photocatalyst titanium dioxide is loaded on the fabric by spraying, and chloroprene rubber is used as the adhesive, so that the titanium dioxide can be stably dispersed and fixed on the surface of the fabric, and the chloroprene rubber can be partially aged and dechlorinated by aging titanium dioxide for a long time. . However, chloride ions can be stably adsorbed on the surface of TiO2, which significantly changes the surface charge of TiO2, making the surface of TiO2 on the surface of coated fabrics negatively charged in different pH ranges (this has been proved by the zeta potential characterization in Figure 2), thereby making the surface of TiO2 negatively charged. The catalytic coated fabric has better adsorption performance for cationic dyes, and the dyes adsorbed on the surface of titanium dioxide will cause self-sensitized degradation, so the photocatalytic coated fabric has better degradation effect on cationic dyes. In addition, part of the chlorine can be doped into the lattice of TiO2, displacing the lattice oxygen (this has been proved by the XPS characterization in Figure 4), since the atomic radius of chlorine is larger than that of oxygen, it can cause defects in TiO2, and these defects may promote the electron- The separation of hole pairs, while reducing the bandgap of TiO2, enhances the absorption of visible light by TiO2 (this has been demonstrated by UV-vis characterization in Figure 3), thereby enhancing the degradation performance of the coated fabrics to dyes under visible light.

Fig. 1 is a scanning electron microscope image of the photocatalytic coated fabric of Example 1. It can be seen from the figure that titanium dioxide is stably dispersed on the surface of the fabric, and a nano-coating is formed on the surface of the fabric.

Fig. 2 is the Zeta potential diagram of Cl-TiO ₂ powder obtained from the photocatalytic coated fabric of Example 1 (obtained by grinding, ultrasonication, washing, filtration) and P25 powder, it can be seen from the figure that Cl-TiO ₂ is in the whole pH range Both are negative values, indicating that the adsorption of chloride ions on the surface of titanium dioxide can significantly change the chargeability of the surface of titanium dioxide and promote the negative charge on the surface of titanium dioxide.

Fig. 3 is the UV-vis image of the photocatalytic coated fabric of Example 1 and the titanium dioxide coated fabric without neoprene coating, it can be seen from the figure that the visible light absorption intensity of the photocatalytic coated fabric greater than 400 nm is significantly higher than that of the titanium dioxide coating fabric.

4 is the XPS spectrum of Cl-TiO ₂ powder obtained from the photocatalytic coated fabric of Example 1, wherein a is the XPS full spectrum of Cl-TiO ₂ , and b is the Cl element XPS spectrum. It can be seen from Figure a that Cl-TiO ₂ contains four elements of C, O, Ti, and Cl. It can be seen from Figure b that there are three forms of Cl, the low binding energy at 197.9 eV is mainly attributed to the chemisorption of chloride ions on the surface of TiO, and the binding energy at about 200.0 eV may be the peak of anionic Cl doped into the _TiO lattice , by displacing oxygen in the _TiO lattice, possibly forming Ti-Cl-Ti bonds. And the high binding energy at 201.7 eV might be the chlorine bound in the neoprene on the _TiO surface.

Figure 5 is a graph of the photocatalytic coating fabric of Example 1 that degrades the dye Rhodamine B multiple times under visible light. It can be seen from the figure that the photocatalytic coating fabric has no reduction in the effect of degrading Rhodamine B after multiple uses, and has good recycling performance.

Beneficial effects of the present invention:

(1) The preparation method of the photocatalytic fabric provided by the present invention is simple in process, mild in conditions, carried out at room temperature, does not require a subsequent calcination process, significantly saves energy and reduces consumption, and is suitable for large-scale treatment and production.

(2) The prepared photocatalytic fabric coating has good photodegradation performance of dyes in water, is suitable for photodegradation treatment of dye pollutants in industrial production and environment, and can well realize the recycling of catalysts and save the treatment cost. , has good commercial application prospects. .

Description of drawings

Fig. 1 is the electron microscope (SEM) figure of example 1 photocatalytic coating fabric;

Fig. 2 is the Zeta potential diagram of Cl-TiO ₂ powder and P25 powder obtained from the photocatalytic coated fabric of Example 1 in Example 1;

Fig. 3 is the UV-vis figure of the fabric obtained in Example 1 and Comparative Example;

Fig. 4 is the XPS spectrum of Cl-TiO ₂ powder obtained from the photocatalytic coated fabric of Example 1, a is the Cl-TiO ₂ XPS full spectrum, and b is the Cl XPS spectrum;

Fig. 5 is the photocatalytic coating fabric of example 1 photocatalytic coating fabric under visible light cycle degradation dye rhodamine B figure;

Detailed ways

Example 1:

A. Select the fluoromex fabric, cut the fabric of 20cm*20cm, measure 100ml of ethanol and 100ml of acetone and mix it into a 400ml beaker, fold the fabric and soak it in the solution, ultrasonically clean the fabric for 60min, and then put The fabric was placed in an oven at 80°C for drying for 120 min, and the fabric was taken out after the mixture was completely evaporated.

B. Measure 100ml of absolute ethanol into a 200ml beaker, accurately weigh 1.0g of commercial titanium dioxide, add it to absolute ethanol, stir for 10min and then ultrasonicate for 1h, so that titanium dioxide is completely dispersed in ethanol to obtain a titanium dioxide suspension.

C. Weigh 10g of neoprene and dissolve it in 60ml of xylene and stir for 12h. After the neoprene is completely dissolved, it will be viscous and evenly coated on both sides of the fabric.

D. Add the titanium dioxide suspension liquid to the high-pressure spray gun, shake well, and connect the vacuum pump. The neoprene rubber on the surface of the fabric described in step C is evenly sprayed on the surface of the fabric before it is dry, so as to obtain a coated fabric loaded with titanium dioxide on both sides. The coated fabric was dried in an oven at 80°C for 2 h, and then aged at room temperature for 108 h to obtain a photocatalytic coated fabric.

Performance evaluation: Prepare 100ml of dye solution with a concentration of 10mg/L in two beakers respectively, add cationic dye Rhodamine B and anionic methyl orange to the beakers respectively, and then cut two pieces of 5cm*5cm light. The catalytic coated fabric is put into two beakers, magnetic stirring is adsorbed for 30min, sampled once, and then irradiated with a xenon lamp with a power of 300W (wavelength λ>420nm) to simulate sunlight (light intensity 100mW/cm ² ), and the dye is determined by sampling every 10min absorbance and calculate the degradation rate.

The specific sampling steps are: take out 3ml of the solution from the beaker with a pipette, measure the absorbance of the dye solution in the samples taken at each time period with a Shimadzu UV-2501PC ultraviolet absorption spectrophotometer, and measure the original solution at the maximum absorption wavelength of the dye. and the absorbance values A ₀ and At of the solution after the reaction, and calculate the degradation degree of the dye by the photocatalytic coated fabric using At/A ₀ =Ct/C _o =η. The results are shown in Table 1.

After the test, the photocatalytic coated fabric was washed with ethanol and deionized water, and then placed in an oven at 80 °C for drying for 5 h. After the coated fabric was dried, it was taken out to cool at room temperature, and the above experiment of visible light degradation of rhodamine B was repeated 8 times. The results are shown in Figure 5. The photocatalytic coating fabric did not have a significant decrease in the effect of degrading the dye Rhodamine B, indicating that it has a good recycling performance.

Example 2:

A. Select the acrylic filter fabric, cut the fabric of 20cm*20cm, measure 100ml of ethanol and 100ml of acetone and mix it into a 400ml beaker, fold the fabric and soak it in the solution, ultrasonically clean the fabric for 60min, then Put the fabric in an oven at 80°C to dry for 120 min, and take out the fabric after the mixed liquid is completely evaporated.

B. Measure 100ml of absolute ethanol into a 200ml beaker, accurately weigh 0.8g of commercial titanium dioxide, add it to absolute ethanol, stir for 10min and then ultrasonicate for 1h, so that titanium dioxide is completely dispersed in ethanol to obtain a titanium dioxide suspension.

C. Weigh 12.5g of neoprene and dissolve it in 60ml of xylene and stir for 12h. After the neoprene is completely dissolved, it will be viscous and evenly coated on both sides of the fabric.

D. Add the titanium dioxide suspension liquid into the high-pressure spray gun, shake well, and connect to the vacuum pump. After the chloroprene rubber on the fabric surface described in step C was evenly sprayed on the surface of the fabric immediately before it was dry, a coated fabric with titanium dioxide on both sides was obtained. After aging for 108h, the photocatalytic coated fabric was obtained.

The degradation of the two dye solutions was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 3:

A. Select coral fleece fabric, cut 20cm*20cm fabric, measure 100ml of ethanol and 100ml of acetone and mix it into a 400ml beaker, fold the fabric and soak it in the solution, ultrasonically clean the fabric for 60min, then the fabric Put it in an oven at 80°C to dry for 120min, and take out the fabric after the mixture is completely evaporated.

B. Measure 100ml of absolute ethanol into a 200ml beaker, accurately weigh 1.5g of commercial titanium dioxide, add it to absolute ethanol, stir for 10min and then ultrasonicate for 1h, so that titanium dioxide is completely dispersed in ethanol to obtain a titanium dioxide suspension.

C. Weigh 7.5g of neoprene and dissolve it in 60ml of xylene and stir for 12h. After the neoprene is completely dissolved, it will be viscous and evenly coated on the surface of the fabric.

D. Add the titanium dioxide suspension liquid into the high-pressure spray gun, shake well, and connect to the vacuum pump. The chloroprene rubber on the surface of the fabric described in step C is immediately and evenly sprayed on the surface of the fabric to obtain a coated fabric loaded with titanium dioxide on both sides. The coated fabric was dried in an oven at 80°C for 2 h, and then the coated fabric was aged at room temperature for 108 h to obtain a photocatalytic coated fabric.

The degradation of the two dye solutions was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 4:

A. Select the double-sided fleece fabric, cut the fabric of 20cm*20cm, measure 100ml of ethanol and 100ml of acetone and mix it into a 400ml beaker, fold the fabric and soak it in the solution, ultrasonically clean the fabric for 60min, and then put The fabric was placed in an oven at 80°C for drying for 120 min, and the fabric was taken out after the mixture was completely evaporated.

B. Measure 100ml of absolute ethanol and add it to a 200ml beaker, accurately weigh 1.2g of commercial titanium dioxide (P25), add it to absolute ethanol, stir for 10min and then ultrasonicate for 1h, so that titanium dioxide is completely dispersed in ethanol to obtain a titanium dioxide suspension .

C. Weigh 15g of neoprene and dissolve it in 60ml of xylene and stir for 12h. After the neoprene is completely dissolved, it will be viscous and evenly coated on the surface of the fabric.

D. Add the titanium dioxide suspension liquid into the high-pressure spray gun, shake well, and connect to the vacuum pump. The chloroprene rubber on the surface of the fabric described in step C is immediately and evenly sprayed on the surface of the fabric to obtain a coated fabric loaded with titanium dioxide on both sides. The coated fabric was dried in an oven at 80°C for 2 h, and then the coated fabric was aged at room temperature for 108 h to obtain a photocatalytic coated fabric.

The degradation of the two dye solutions was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative ratio

According to the method of Example 1, except that the operation of step C is removed, a P25 fabric without neoprene coating is obtained.

The degradation of the two dye solutions was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Table 1. Determination of the performance of photocatalytic fabrics to degrade dyes

Claims (2)

1. a kind of preparation method of photocatalysis coating fabric, specific preparation process is as follows:

A. ethyl alcohol and acetone are added in container in the ratio of 1:1 and are uniformly mixed and obtain mixed solution, by selected fabric Be cut into according to the needs of use it is suitably sized be immersed in above-mentioned mixed solution, ultrasonic 60-100min cleans fabric, then will knit Object is dried in 60-80 DEG C；The fabric be fluorine beauty this, one of sub- gram filtrate, coral fleece, double-sided plush；

B. titanium dioxide is added to absolute ethanol, ultrasound 1-3h divides titanium dioxide completely in ethanol to stirring 10-30min again It dissipates and obtains tio_2 suspension, wherein the concentration of titanium dioxide is 2.5-10g/L；

The titanium dioxide is the commercial titanium dioxide of model P25, and crystal form is Detitanium-ore-type and rutile-type ratio is The mixing crystal form of 4:1 composition；

C. neoprene is dissolved in stirring in dimethylbenzene until being completely dissolved, wherein neoprene concentration is 80-280g/L, by it It is uniform to be coated in the two-sided of fabric described in step A；

D. the tio_2 suspension of step B is added in high-pressure spray gun, is shaken up, it is not dry in step C fabric surface neoprene It is equably sprayed on fabric two-face before, it is dried in 50-90 DEG C of drying or room temperature to get two-sided carried titanium dioxide is arrived Coated fabric；Ageing 96-168h obtains photocatalysis coating fabric at room temperature.

2. a kind of application of photocatalysis coating fabric described in claim 1, which prints and dyes applied to photocatalytic degradation Other pollutants in waste water and water body.