CN115999583A - Feather carbonization modified titanium dioxide aerogel photocatalyst, preparation and application - Google Patents

Abstract

The invention discloses feather feather carbonization modified titanium dioxide airgel photocatalyst, preparation and application. The method steps of the preparation of the catalyst are as follows: S1: dissolving butyl titanate in absolute ethanol to obtain solution A; S2: dissolving Dissolve water ethanol and glacial acetic acid in deionized water to obtain solution B; S3: add solution B to solution A, stir to obtain a uniform sol, then add feather feathers to stir and age at room temperature, and after drying, it contains Gel of feather down; S4: Calcining the gel in S3 to prepare modified titanium dioxide airgel visible light catalyst. The present invention can form an airgel structure during the reaction process, thereby improving the production efficiency of the airgel catalyst and reducing the preparation cost, and the prepared photocatalyst has a hydrophobic side and a hydrophilic Janus structure, so it has excellent water evaporation It has excellent photocatalytic degradation of organic pollutants under both ultraviolet light and visible light.

Description

Photocatalyst, preparation and application of titanium dioxide airgel photocatalyst modified by carbonization of feather down

technical field

The invention relates to the technical field of photocatalysts, in particular to carbonization-modified titanium dioxide airgel photocatalysts, preparation and application of feather down.

Background technique

TiO ₂ airgel has excellent characteristics such as ultra-low density, high specific surface area and porosity, strong oxidation ability, high oxidation activity and adsorption, and good chemical and optical stability. It has important applications in the fields of solar energy conversion and photocatalysis. prospect.

At present, TiO ₂ airgel mainly adopts supercritical drying method, which has harsh conditions, high cost, and the efficiency of the prepared photocatalyst is not high. Therefore, the object of the present invention is to provide a new carbon-based photocatalyst doped with titanium dioxide to improve the catalyst's cost performance and wastewater treatment efficiency.

Contents of the invention

Based on the technical problems existing in the background technology, the present invention proposes the carbonization modified titanium dioxide airgel photocatalyst of feather down, its preparation and application in wastewater treatment. The airgel structure can be formed during the reaction process, thereby improving the photocatalyst. Production efficiency, and the prepared catalyst has excellent photocatalytic performance.

The preparation method of the feather feather carbonization modified titanium dioxide airgel photocatalyst proposed by the present invention, the method steps are as follows:

S1: dissolving titanate in absolute ethanol to obtain solution A;

S2: Dissolve absolute ethanol and glacial acetic acid in deionized water to obtain solution B;

S3: Add solution B into solution A, stir to obtain a uniform sol, then add feather down, stir and age at room temperature, and after drying, it will become a gel containing feather down;

S4: calcining the gel containing feather down in S3 to obtain a carbonized titanium dioxide airgel photocatalyst modified by feather down.

Preferably, the titanate is butyl titanate and/or isobutyl titanate.

Preferably, the molar ratio of the titanate, glacial acetic acid, absolute ethanol and deionized water is 12-18:2-4:6-10:1; the molar ratio of the amount of absolute ethanol in S1 and S2 is 1-3:1.

Preferably, the aging time in S3 is 1.5-2.5h.

Preferably, the drying conditions in S3 are: temperature 60-100°C, time 10-20h.

Preferably, the conditions for calcination in S3 are: heating up to 450-550° C. for 0.5-1.5 hours, keeping the temperature for 1.5-2.5 hours, and then cooling down to 80-100° C. before taking it out.

The feather down carbonization modified titanium dioxide airgel photocatalyst prepared by the method proposed in the present invention.

Preferably, the catalyst is hydrophilic on one side and hydrophobic on the other, having a Janus structure.

The invention proposes the application of the feather down carbonization-modified titanium dioxide airgel photocatalyst in the treatment of wastewater containing organic pollutants.

Beneficial technical effect of the present invention:

(1) The present invention can form airgel after aging, drying and calcination by mixing feather down with the solution, that is, the airgel of the present invention can be formed during the catalyst preparation process without additional treatment , thus improving the production efficiency of the photocatalyst.

(2) The photocatalyst of the present invention has a porous airgel structure and has an excellent pollutant degradation effect when treating wastewater.

(3) The structure of part of the rachis of the conventional feather feather breaks when it is above 300° C., the structure of most of the barbs has been completely carbonized and disappeared, and the fiber structure is destroyed. When the technology of the present invention is calcined at about 500° C., The prepared photocatalyst is divided into blocks of different sizes. After calcination, it maintains the fiber structure of feathers. Titanium dioxide can fully cover the feathers, and there is a slight agglomeration between the particles. ; The fibrous structure maintained by the feather down enables the catalyst to have a porous and fluffy structure with a high specific surface area, which in turn can fully adsorb and degrade pollutants.

(4) There are trace metal elements and disulfide bonds in the feather down of the present invention, so that the activity of the catalyst can be further improved after being doped with titanium dioxide.

(5) The photocatalyst prepared by the present invention has a Janus structure with one side hydrophobic and the other side hydrophilic, so it has excellent water evaporation performance, and has excellent photocatalytic effect under ultraviolet light and visible light.

Description of drawings

Fig. 1 is the SEM figure of the feather feather proposed by the present invention at different carbonization temperatures; wherein (a) is before carbonization; (b-e) carbonization temperatures are respectively 260°C, 280°C, 300°C and 320°C;

Fig. 2 is the SEM figure before and after calcination of the gel containing down proposed by the present invention; wherein (a) is before calcination, (b) is after calcination;

Fig. 3 is a graph showing contact angle test results of the original down feather proposed by the present invention and the down carbonization modified titanium dioxide airgel photocatalyst prepared in Example 1.

Detailed ways

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

Example 1

The preparation method of the feather feather carbonization modified titanium dioxide airgel photocatalyst proposed by the present invention, the method steps are as follows:

S1: Dissolve 17ml of butyl titanate in 24ml of ethanol, and stir magnetically for 0.5h to obtain A solution;

S2: Mix 12ml of ethanol with 9ml of glacial acetic acid and 7.2ml of deionized water, and stir magnetically for 0.5h to obtain solution B;

S3: Put the prepared B solution in the plastic dropper and drop it into the A solution at 2 drops/s, and stir it magnetically for 2 hours to obtain a uniform sol, put 0.5g of feather down and stir well, and age at room temperature Put it in a drying oven for 15 hours at 80°C to obtain a gel containing feather down, put it into a tube furnace for calcination, heat up to 500°C after 1 hour, keep it at 500°C for 2 hours, and take it out after cooling down to 100°C. A carbonized titanium dioxide airgel photocatalyst modified by feather down was obtained.

Example 2

The preparation method of the feather feather carbonization modified titanium dioxide airgel photocatalyst proposed by the present invention, the method steps are as follows:

S1: Dissolve 15ml of butyl titanate in 20ml of ethanol, and magnetically stir for 0.5h to obtain A solution;

S2: Mix 10ml of ethanol with 7ml of glacial acetic acid and 6ml of deionized water, and stir magnetically for 0.5h to obtain solution B;

S3: Put the prepared B solution in the rubber dropper and drop it into the A solution at 1 drop/s, stir it magnetically for 2 hours to obtain a uniform sol, put in 0.5g of feather feather and stir well, and age at room temperature 1.5h, put it in a drying oven at 60°C for 20h, get a gel containing feather down, put it into a tube furnace for calcination, heat up to 450°C after 0.5h, keep it at 450°C for 1.5h, and cool down to 80°C After taking it out, the feather down carbonization modified titanium dioxide airgel photocatalyst is obtained.

Example 3

The preparation method of the feather feather carbonization modified titanium dioxide airgel photocatalyst proposed by the present invention, the method steps are as follows:

S1: Dissolve 20ml of butyl titanate in 26ml of ethanol, and stir magnetically for 0.5h to obtain A solution;

S2: Mix 15ml of ethanol with 10ml of glacial acetic acid and 9ml of deionized water, and stir magnetically for 0.5h to obtain solution B;

S3: Put the prepared B solution in the rubber dropper and drop it into the A solution at 1 drop/s, stir it magnetically for 2 hours to obtain a uniform sol, put in 0.5g of feather feather and stir well, and age at room temperature 2.5h, put it in a drying oven at 100°C and dry for 10h to get a gel containing feather down, put it into a tube furnace for calcination, heat up to 550°C after 1.5h, keep warm at 550°C for 2.5h, and cool down to 100°C After taking out, feather down carbonization modified titanium dioxide airgel photocatalyst.

After cleaning and drying some feather down, carbonization treatment was carried out in a carbonization furnace at different temperatures. The heating rate was set at 5°C/min, and the carbonization time was 2h. The results are shown in Figure 1. It can be seen from (b) and (c) of Figure 1 that under the conditions of carbonization temperature of 260 ° C and 280 ° C, the down still retains the fiber structure of its original feather, and the rachis and barbs of the down down Part of the structure is relatively complete, the surface is flat and smooth, and the structure is compact. As the carbonization temperature rises to 300°C (Fig. 1(d)), part of the rachis of the feather down is broken, and most of the barbs have been completely carbonized. disappeared, the fiber structure was destroyed, and the temperature continued to rise to 320°C (Fig. 1(e)), the surface of the down showed a fragmented structure, and the carbon skeleton was broken. It can be seen that the whole down was seriously damaged, and the rachis was partially broken More seriously, the barbs have been completely carbonized and disappeared, and the overall color has changed to coke black, and the lamella structure on the surface continues to increase. The results show that the carbonization temperature has a great influence on the shape of the feather down sample. If the temperature is too high, the carbonization The structure of the back feather down will be damaged to some extent.

However, when analyzing the morphology of the gel containing feather down in Example 1 before and after calcination, it is found that the gel containing feather down before calcination presents a light yellow fluffy structure as a whole, and it can be seen under an electron microscope that it maintains its solidification. Blocky solid with glue structure and complete feather fibrous structure (Fig. 2(a)); the calcined sample presents a black blocky solid, which itself is very brittle and has low strength, and becomes powder when slightly impacted. After scanning electron microscope analysis, it can be seen from Figure 2(b) that the gel is split into blocks of different sizes, and after carbonization, it maintains the fiber structure of feathers. Titanium dioxide can fully wrap feathers, and there is a slight agglomeration between particles. Blocky particles have a slightly porous structure and a larger specific surface area. That is to say, when the gel containing feather down is calcined at a higher temperature (500° C.) by the process of the present application, the down down can still maintain the fiber structure, and it is based on this that the catalyst has a porous and fluffy structure with a high specific surface area. structure, which can fully absorb and degrade pollutants.

In order to show more intuitively the hydrophilicity of the down carbonization modified titanium dioxide airgel photocatalyst, the original feather down and the feather down carbonization modification titanium dioxide airgel photocatalyst prepared in Example 1 and the deionized water The contact angle was measured, and the sample was dried for 2 hours before the test, and then the high-speed camera of the contact angle meter was used to take pictures of the water droplets touching the sample, and the angle of the liquid-solid interface was obtained by fitting the water droplets on the surface of the sample by the five-point fitting method. The result As shown in Figure 3. The non-carbonized feather down has poor hydrophilicity and the contact angle is 146.528°. After carbonization, the color of the feather down becomes black, and the contact angle decreases from 146° to 99°, which shows that the carbonized feather down surface has With a certain degree of hydrophilicity, water can be transmitted from the lower surface to the upper surface, and the generated water vapor can also escape from the upper surface, ensuring the water supply when the sample evaporates; at the same time, the feather down carbon-based material is filtered The film formation can float on the surface of the liquid, indicating that the upper surface of the feather down carbonized material has a certain degree of hydrophobicity, and this hydrophobic surface ensures the self-floating performance of the feather down-based carbon material.

In order to verify the treatment effect of the feather down carbonized modified titanium dioxide airgel photocatalyst on wastewater, the photocatalytic degradation device was used to conduct continuous water treatment of different lengths of time on the feather down carbonized modified titanium dioxide airgel photocatalyst prepared in Example 1. In the treatment test, the pollution simulant was methyl orange solution, and the light source used two kinds of light sources, ultraviolet light and visible light, to carry out the degradation experiment. The degradation conditions are shown in Table 1. The degradation rate of methyl orange in the gel can reach 98% in 18 hours under visible light, and the degradation rate of ultraviolet light is better, because TiO ₂ has a wide band gap, and the utilization rate is high under ultraviolet light. Low utilization. However, titanium dioxide is doped with feather down, so that titanium dioxide is doped with non-metallic elements such as C, N, S, etc., so that _TiO2 can show a positive effect in the visible light region and has high photocatalytic activity. In addition, the incorporation of C can form carbon species on the surface of TiO ₂ catalyst, and these carbon species contribute to the further absorption of visible light by TiO ₂ . It is further proved that titanium dioxide doped with feather down can effectively broaden the visible light photoresponse range of _TiO2 . Narrow band gap, which makes it effective in degrading different kinds of organic pollutants under both ultraviolet and visible light irradiation, and has excellent photocatalytic activity.

Table 1 methyl orange degradation effect

In addition, the water evaporation performance of the feather down carbonization modified titanium dioxide airgel photocatalyst prepared in Example 1 is measured, the specific method is: (1) cutting the materials of the control group and Example 1 into a size of 2.5cm* The specification of 2.5cm*0.5cm; (2) Fill a square glass mold with a length, width, and height of 2.5cm with deionized water, and place the material flat on the water surface to make the material wet; (3) Use a ruler to measure out The distance between the liquid surface and the platform is 2cm, keep the ambient temperature around 25°C, and the humidity below 40%, turn on the switch of the fully automatic AC voltage stabilizer (TND-2000VA, Zhejiang Delixi Electric Co., Ltd.), and turn on the simulated sunlight xenon lamp Switch the light source (PL-XQ500W, Beijing Prince Technology Co., Ltd.), adjust the current to 19.2A, connect to the computer software, record the quality of water every 5 minutes, and record the quality change for one hour continuously; The results are shown in Table 2, where the control group is carbonized feather down material without adding titanium dioxide.

Table 2 Water evaporation performance test

From the test results in Table 1, it can be seen that the Janus structure formed by doping titanium dioxide in the down carbonized material of the present invention has excellent water evaporation performance, and the water evaporation rate is close to that of feathers without adding titanium dioxide. 2 times that of plush carbonized material.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (9)

1. The preparation method of the feather carbonization modified titanium dioxide aerogel photocatalyst is characterized by comprising the following steps:

s1: dissolving titanate in absolute ethyl alcohol to obtain a solution A;

s2: dissolving absolute ethyl alcohol and glacial acetic acid in deionized water to obtain a solution B;

s3: adding the solution B into the solution A, stirring to obtain uniform sol, adding feather down, stirring, aging at room temperature, and drying to obtain gel containing the feather down;

s4: and (3) calcining the gel in the step (S3) to obtain the feather down carbonization modified titanium dioxide aerogel photocatalyst.

2. The method for preparing a feather down carbonization modified titanium dioxide aerogel photocatalyst according to claim 1, wherein the titanate is butyl titanate and/or isobutyl titanate.

3. The method for preparing the feather down carbonization modified titanium dioxide aerogel photocatalyst according to claim 1, wherein the molar ratio of titanate to glacial acetic acid to absolute ethanol to deionized water is 12-18:2-4:6-10:1; the dosage mole ratio of the absolute ethyl alcohol in S1 and S2 is 1-3:1.

4. The method for preparing a feather down carbonization modified titanium dioxide aerogel photocatalyst according to claim 1, wherein the aging time in S3 is 1.5-2.5h.

5. The method for preparing the feather down carbonization modified titanium dioxide aerogel photocatalyst according to claim 1, wherein the drying conditions in S3 are as follows: the temperature is 60-100 ℃ and the time is 10-20h.

6. The method for preparing the feather down carbonization modified titanium dioxide aerogel photocatalyst according to claim 1, wherein the calcining conditions in S3 are as follows: heating to 450-550deg.C for 0.5-1.5 hr, maintaining the temperature for 1.5-2.5 hr, cooling to 80-100deg.C, and taking out.

7. A feather down carbonized modified titanium dioxide aerogel photocatalyst prepared by the method of any one of claims 1 to 6.

8. The catalyst of claim 7, wherein one side of the catalyst is hydrophilic and the other side is hydrophobic, and has a Janus structure.

9. Use of the feather down carbonization modified titanium dioxide aerogel photocatalyst of claim 7 or 8 in the treatment of wastewater containing organic pollutants.

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