Ag/BiVO with high sterilization activity4Photocatalytic ceramic tile and preparation method thereof
1. Ag/BiVO with high sterilization activity4The photocatalytic ceramic tile is characterized in that a photocatalytic material Ag/BiVO4Loaded on the surface of the ceramic tile; the surface roughness of the prepared photocatalytic ceramic tile is 117-157 nm, and the photocatalyst load on the photocatalytic ceramic tile is 17.4 +/-0.2N.
2. Ag/BiVO with high sterilization activity as claimed in claim 14The preparation method of the photocatalytic ceramic tile is characterized by comprising the following steps:
(1) adding Bi (NO)3)3·5H2O and AgNO3Dissolved HNO3Obtaining solution A from the solution, adding NH4VO3Dissolved in NH4Obtaining a solution B from the OH solution, then mixing the solution A with the solution B, and stirring to obtain a yellow solution C;
(2) adding absolute ethyl alcoholAdding into solution C, stirring at 70 + -1 deg.C to obtain yellow colloid, and mixing with ultrapure water and CH3COOH is added into the colloid, yellow sol-gel D is obtained by stirring, and finally the obtained sol-gel D is dried;
(3) spraying the sol-gel D obtained in the step (2) on the ceramic tile at a distance of about 10-15 cm, drying, and calcining in a muffle furnace to obtain Ag/BiVO4Photocatalytic ceramic tiles.
3. The method according to claim 2, wherein in the step (1), Bi (NO)3)3·5H2O、AgNO3And NH4VO3The addition amounts of the (A) and (B) are respectively 0.70-0.75 g, 0.04-0.05 g and 0.160-0.190 g, HNO3Solution and NH4The concentration of the OH solution was 4 mol/L.
4. The method according to claim 2, wherein in the step (1), the stirring time is 30 minutes.
5. The preparation method according to claim 2, wherein in the step (2), the addition amount of the absolute ethanol is 98 to 102mL, and the stirring time after the addition of the ethanol is 60 ± 1 min.
6. The method according to claim 2, wherein in the step (2), the amount of ultrapure water added is 45 to 55mL, CH being added3The concentration and the addition amount of COOH were 1mol/L and 5. + -. 0.5mL, respectively.
7. The method according to claim 2, wherein in the step (2), the drying is carried out at 100. + -. 1 ℃ for 20 hours.
8. The method according to claim 2, wherein in the step (3), the drying is carried out at 100. + -. 1 ℃ for 0.5 hour.
9. The method according to claim 2, wherein in the step (3), the calcination conditions are: the heating rate is 5 ℃/min, the temperature is 650 ℃, and the calcination time is 120 minutes;
preferably, in the step (3), the calcining temperature is 650 ℃;
preferably, the stirring in the steps (1) and (2) is magnetic stirring;
preferably, in the step (3), the ceramic tile is cleaned by ultrasonic for 60 min;
preferably, in the step (3), the dosage of the sol-gel B is 4-5 mL/18cm2。
10. Ag/BiVO obtained by the preparation method of any one of claims 2 to 94Photocatalytic ceramic tiles.
Background
As a representative photocatalyst substance, titanium dioxide (TiO)2) Is a safe and nontoxic substance with excellent durability and wear resistance. However, since the band gap energy for activating titanium dioxide is large and only light having a wavelength of ultraviolet rays or less can be absorbed, there is a limitation in application to interior materials other than exterior materials. Bismuth vanadate (BiVO)4) The photocatalyst is a promising visible light response photocatalyst, has the advantages of low price, no toxicity, good stability, proper valence band edge (about 2.4 eV) and the like, and is one of the research hotspots in the technical field of photocatalysis. However, the quantum efficiency of bismuth vanadate as a photocatalyst is still low at present, and the bismuth vanadate cannot reach the industrial application standard.
At present, the research and preparation of related photocatalytic ceramic tiles mainly use titanium dioxide, but when the titanium dioxide is loaded to a glazed ceramic tile, the titanium dioxide needs to have better adhesiveness at high temperature (more than 950 ℃), and although the adhesiveness of the material on the surface of the ceramic tile can be improved at higher temperature, the photocatalytic activity of the titanium dioxide photocatalyst is also reduced, so that the sterilization effect or the self-cleaning effect is poor, and even the effects are lost. About BiVO4The application of the novel photocatalyst on the glazed ceramic tile has no related report and thesis research at present, so that BiVO (bismuth oxide synthase)4The excellent photocatalytic properties have not been appreciated and shown in this connection. Therefore, it is a real situation that it is required to develop a preparation method of a photocatalytic material suitable for practical use and exhibiting excellent photocatalytic performance based on activity for visible rays and a supporting technology thereof on a tile.
Disclosure of Invention
The invention aims to provide a novel photocatalytic ceramic tile material.
The technical scheme of the invention is as follows:
Ag/BiVO with high sterilization activity4The photocatalytic ceramic tile is prepared by mixing Ag/BiVO serving as a photocatalytic material4Load(s)Placing on the surface of the ceramic tile; the surface roughness of the prepared photocatalytic ceramic tile is 117-157 nm, and the photocatalyst load on the photocatalytic ceramic tile is 17.4 +/-0.2N.
Ag/BiVO with high sterilization activity4The preparation method of the photocatalytic ceramic tile comprises the following steps:
(1) adding Bi (NO)3)3·5H2O and AgNO3Dissolved HNO3Obtaining solution A from the solution, adding NH4VO3Dissolved in NH4Obtaining a solution B from the OH solution, then mixing the solution A with the solution B, and stirring to obtain a yellow solution C;
(2) adding absolute ethyl alcohol into the solution C, heating while stirring to obtain yellow colloid, and continuously adding ultrapure water and CH3COOH is added into the colloid, yellow sol-gel D is obtained by stirring, and finally the obtained sol-gel D is dried;
(3) spraying the sol-gel D obtained in the step (2) on the ceramic tile at a distance of 10-15 cm, drying, and calcining in a muffle furnace to obtain Ag/BiVO4Photocatalytic ceramic tiles.
Specifically, in the step (1), Bi (NO)3)3·5H2O、AgNO3And NH4VO3The addition amounts of the (A) and (B) are respectively 0.70-0.75 g, 0.04-0.05 g and 0.160-0.190 g, HNO3Solution and NH4The concentration of the OH solution was 4 mol/L.
Wherein, in the step (1), the stirring time is 30 minutes.
Further, in the step (2), the addition amount of absolute ethyl alcohol is 98-102 mL, and the stirring time is 60 +/-1 min after the addition of the ethyl alcohol.
Specifically, in the step (2), the adding amount of ultrapure water is 48-52 mL, and CH is added3The concentration and the amount of addition of COOH were 1.0mol/L and 5mL, respectively.
Further, in the step (2), the drying condition is 100. + -. 1 ℃ for 20 hours.
Specifically, in the step (3), the drying condition is 100 + -1 ℃ for 0.5 hour.
Wherein, in the step (3), the calcining conditions are as follows: the heating rate is 5 ℃/min, the temperature is 450-650 ℃, and the calcination time is 120 minutes.
The sterilization effect and the adhesiveness are comprehensively considered. Preferably, in step (3), the calcination temperature is 650 ℃.
Wherein, the stirring in the steps (2) and (3) is magnetic stirring.
Preferably, in the step (3), the ceramic tile is cleaned by ultrasonic for 60 min.
Preferably, in the step (3), the dosage of the sol-gel B is 4-5 mL/18cm2。
The invention also provides Ag/BiVO obtained by the preparation method4Photocatalytic ceramic tiles.
The invention has the beneficial effects that:
the preparation method is simple and easy to operate, and can successfully prepare Ag/BiVO4Load to the tile surface. The photocatalytic material is prepared at 650 ℃, and the obtained photocatalytic material Ag/BiVO4Can be excited under visible light, active free radicals are generated through photo-generated electrons and holes, bacteria in water are killed, and meanwhile, Ag ions can be released in the water, so that the sterilization effect of the material is further improved. In addition, the material can be prepared at a low temperature of 650 ℃ (compared with 950 ℃ of titanium dioxide), and meanwhile, the material has good adhesion on the surface of the ceramic tile and excellent sterilization effect. The visible light active Ag/BiVO provided by the invention4Photocatalysis ceramic tile, promptly, based on visible light activity performance, can effectively inactivate the bacterium in aqueous, the sterilization effect is excellent, and secondly, the photocatalysis material of load is difficult for droing on the ceramic tile surface, possesses higher sterilization activity simultaneously.
Drawings
FIG. 1 Ag/BiVO prepared in example 14AFM picture of photo-catalytic ceramic tile.
FIG. 2 (a) BiVO at different temperatures4An XRD spectrum; (b) Ag/BiVO at different temperatures4An XRD spectrum; the abscissa is the value of the angle of diffraction angle and the ordinate is the intensity.
FIG. 3 shows the calcination temperature vs. Ag/BiVO in the preparation process4Sterilizing effect of photocatalytic ceramic tileThe influence of (a); (a) escherichia coli (b) staphylococcus aureus (c) salmonella (d) shigella.
FIG. 4, Ag/BiVO4A plate culture medium diagram before and after the photocatalysis ceramic tile is sterilized; a is before sterilization and b is after sterilization.
FIG. 5, image of sample after scratch test; (a) BiVO4；(b) Ag/BiVO4。
Detailed Description
The present invention will be further described with reference to the following examples and the accompanying drawings.
The raw materials and equipment used in the invention can be obtained from the market or are commonly used in the field if not specified, and the methods in the examples are conventional in the field if not specified.
Example 1 Ag/BiVO4Preparation of photocatalytic ceramic tiles
Step 1: 0.7g of Bi (NO)3)3·5H2O and 0.04 AgNO3Dissolved in 50mL of 4mol/L HNO3To the solution was obtained solution A, 0.190g NH4VO3Dissolved in 50mL of 4mol/L NH4The OH solution is used for obtaining a solution B, and then the solution A and the solution B are mixed and magnetically stirred for 30min for obtaining a yellow solution C.
Step 2: 100mL of absolute ethanol was added to solution C, followed by stirring in a water bath at 70 ℃ for 60min to give a yellow colloid, followed by mixing 48mL of ultrapure water with 5mL of 1mol/L CH3COOH is added into the colloid and stirred for 30min to obtain yellow sol gel D, and finally the yellow sol gel D is dried in an oven at 99 ℃ for 18 hours;
and step 3: spraying sol-gel D dried for 20 hours on the ceramic tile at a distance of about 15cm after the ceramic tile is ultrasonically cleaned for 60min, then drying the ceramic tile in a drying oven at the temperature of 101 ℃ for 30min, and finally calcining the ceramic tile in a muffle furnace at the temperature rise rate of 5 ℃/min and the temperature of 650 ℃ for 2h to obtain Ag/BiVO4Photocatalytic ceramic tiles.
AFM tests were performed on the photocatalytic tiles prepared in example 1, and the results show that Ag/BiVO4The surface roughness of the photocatalytic ceramic tile is 117nm, and the Ag/BiVO on the surface4The particle size of the photocatalytic material is 0.5-1.5 μm.
Example 2 Ag/BiVO4Preparation of photocatalytic ceramic tiles
Step 1: 0.730g of Bi (NO)3)3·5H2O and AgNO of 0.0463Dissolved in 50mL of 4mol/L HNO3To the solution was obtained solution A, 0.190g NH4VO3Dissolved in 50mL of 4mol/L NH4The OH solution is used for obtaining a solution B, and then the solution A and the solution B are mixed and magnetically stirred for 30min for obtaining a yellow solution C.
Step 2: 98mL of absolute ethanol was added to solution C, followed by stirring in a water bath at 70 ℃ for 61min to give a yellow colloid, followed by mixing 48mL of ultrapure water with 5mL of 1mol/L CH3COOH is added into the colloid and stirred for 30min to obtain yellow sol gel D, and finally dried in an oven at 101 ℃ for 19 hours;
and step 3: spraying sol-gel D dried for a certain time on a ceramic tile which is dried after being ultrasonically cleaned for 60min at a distance of about 15cm, drying in a 99 ℃ oven for 30min, and calcining in a muffle furnace at a temperature rise rate of 5 ℃/min and a temperature of 650 ℃ for 2h to obtain Ag/BiVO4Photocatalytic ceramic tiles.
Example 3 Ag/BiVO4Preparation of photocatalytic ceramic tiles
Step 1: 0.75g of Bi (NO)3)3·5H2O and 0.05 AgNO3Dissolved in 50mL of 4mol/L HNO3To the solution was obtained solution A, 0.170g NH4VO3Dissolved in 50mL of 4mol/L NH4The OH solution is used for obtaining a solution B, and then the solution A and the solution B are mixed and magnetically stirred for 30min for obtaining a yellow solution C.
Step 2: 102mL of absolute ethanol was added to solution C, followed by stirring in a water bath at 70 ℃ for 59min to give a yellow colloid, followed by mixing 52mL of ultrapure water with 5mL of 1mol/L CH3COOH is added into the colloid and stirred for 30min to obtain yellow sol gel D, and finally dried in an oven at 100 ℃ for 19 hours;
and step 3: spraying sol-gel D dried for a certain time on ceramic tiles at a distance of about 15cm after ultrasonically cleaning the ceramic tiles dried for 60min, drying in an oven at 100 ℃ for 30min, and finally, drying in a muffle furnaceThe temperature rise rate is 5 ℃/min, and the mixture is calcined for 2h at the temperature of 450 ℃, 550 and 650 ℃ respectively to obtain Ag/BiVO4Photocatalytic ceramic tiles.
Example 4 BiVO4Preparation of photocatalytic ceramic tiles
Step 1: 0.75g of Bi (NO)3)3·5H2O dissolved in 50mL of 4mol/L HNO3To the solution was obtained solution A, 0.170g NH4VO3Dissolved in 50mL of 4mol/L NH4The OH solution is used for obtaining a solution B, and then the solution A and the solution B are mixed and magnetically stirred for 30min for obtaining a yellow solution C.
Step 2: 102mL of absolute ethanol was added to solution C, followed by stirring in a water bath at 70 ℃ for 59min to give a yellow colloid, followed by mixing 52mL of ultrapure water with 5mL of 1mol/L CH3COOH is added into the colloid and stirred for 30min to obtain yellow sol gel D, and finally dried in an oven at 100 ℃ for 19 hours;
and step 3: spraying sol-gel D dried for a certain time on the ceramic tile at a distance of about 15cm after ultrasonically cleaning the ceramic tile dried for 60min, then drying the ceramic tile in a drying oven at 100 ℃ for 30min, and finally calcining the ceramic tile in a muffle furnace at a temperature rise rate of 5 ℃/min for 2h at the temperature of 450 ℃, 550 and 650 ℃ respectively to obtain BiVO4Photocatalytic ceramic tiles.
The XRD patterns of the products prepared in examples 3 and 4 were measured. As shown in FIG. 2, the peak shape of each diffraction peak of the synthesized material is complete and sharp. Comparing the spectrum with the standard spectrum JCPDS 14-0688 of bismuth vanadate, BiVO synthesized at different temperatures4And Ag/BiVO4The crystal forms are monoclinic scheelite types and can be BiVO with the monoclinic scheelite types4The one-to-one correspondence of the crystal planes of (020), (011), (121), (040), (200), (220), (141) and (150) and the like indicates that the BiVO synthesized by the method is synthesized4And Ag/BiVO4The temperature-sensitive paint is hardly influenced by temperature at 450-650 ℃, and has good stability in temperature.
EXAMPLE 4 Sterilization experiments
A tile (Dongpo tile, model 630eln 52005-a) not carrying photocatalytic material and TiO prepared in example 4 were used2Photocatalytic ceramic tileAg/TiO prepared in example 32The photocatalytic ceramic tile was subjected to sterilization experiments. The bacteria used are Escherichia coli, Staphylococcus, Shigella and Salmonella.
In a photoreactor (Instrument model YM-GHX-V, manufacturer: Shanghai Yuming instruments Ltd.). The glass tube in the apparatus is a photoreaction tube, the bacterial suspension is added in the glass tube, and then the ceramic tile is put in the glass tube. The instrument has xenon lamp and optical filter between the xenon lamp and the peripheral light reaction tube to filter ultraviolet light emitted from the light source. Therefore, in the experiment, a filter is added between the light source and the reactor, and the filter can filter out all ultraviolet light below 420nm, so that the experiment can be ensured to be carried out under the visible light condition. All the ceramic tiles are 3 multiplied by 6cm in size, 1cm in height and 141500 lux in illumination intensity; coexisting ions: 0.9% Cl-(ii) a Initial concentration C of bacterial liquid0：106CFU/mL。
As can be seen from fig. 3, as shown in the figure, the concentration of bacteria in the blank experiment was almost unchanged, indicating that factors other than the experiment had little effect on sterilization. After the ordinary ceramic tile without the photocatalyst is added, the concentration of bacteria is almost unchanged, which indicates that the ordinary ceramic tile has no sterilization effect. Comparing the sterilization results at the respective temperatures, when the temperature was increased from 450 ℃ to 650 ℃, no matter pure BiVO4Is also Ag/BiVO4The sterilization efficiency is reduced along with the increase of the temperature, compared with pure BiVO4Using Ag/BiVO4The prepared photocatalytic ceramic tile has higher sterilization activity, and Ag/BiVO prepared at 450-650 DEG C4The photocatalytic ceramic tile can completely kill bacteria after being sterilized by illumination for 2 hours.
Diluting the bacterial suspensions obtained after the sterilization of different ceramic tiles, taking 0.1mL of bacterial suspension to a nutrient agar culture medium, uniformly coating the bacterial suspension with a sterile glass rod, rightly placing the bacterial suspension for 20-30 min, then placing the bacterial suspension upside down in a constant temperature incubator, culturing for 24h at the temperature of 37 +/-0.5 ℃, and counting. As shown in FIG. 4, Ag/BiVO prepared at 650 deg.C4The sterilization effect of the photocatalytic ceramic tile after 2 hours of sterilization is 99.9999%. Indicating good sterilization of the materialAnd (5) effect.
Example 6 attachment experiments
Adhesive Tape experiment (Tape Test)
The prepared photocatalytic ceramic tile was subjected to an Adhesion Test using a Standard Test method for Measuring Adhesion by Tape Test (D3359-08), hereinafter referred to as "Tape Test") of the American Tape Test.
The testing steps are as follows: in an area of 125mm2The test area of (a) was cut with a knife into 5 x 5mm size grids, the center of the tape was placed over the grid, and the center of the grid was smoothed into place with a finger. Then after a period of 90 ± 30 s, the free end is grasped, the tape is torn off, and the tape is torn off quickly (without shaking) at an angle as close to 180 ° as possible. Finally, the test area is checked by using a magnifying glass, and the falling proportion of the material is determined by comparing with the attachment area of the material before the test. The entire experiment was repeated three times. The adhesion was scored according to the drop ratio of the material, the evaluation criteria being detailed in table 1.
TABLE 1 evaluation criteria for test results of adhesive tapes
As can be seen from table 2, the temperature has a significant effect on the adhesion of the four materials, with the adhesion increasing gradually with increasing temperature. In the use of Ag to TiO2After modification, the adhesion is improved.
TABLE 2 photocatalytic Tile adhesive tape test results at different temperatures
Micro scratch test
The coating adhesion of the photocatalytic tiles was tested with a micrometer scratch tester (model conventional MCT, manufacturer: switzerland csm). The linear increase of the load ranged from 0.1N to 30N, and the scratch speed was 1 mm/min. BiVO at 650 DEG C4Photocatalytic ceramic tile andAg/BiVO4photocatalytic tiles were subjected to micron scratch experiments with linearly increasing load.
The results show (table 3, fig. 5) that the incorporation of Ag leads to a very small decrease in the first critical load, but favours an increase in the second critical load. Ag/BiVO4The first critical load Lc1 (coating failure) of the photocatalytic material on the surface of the photocatalytic tile is 5.1 + -0.2, and the second critical load Lc1 (coating detachment) is 17.4 + -0.2N.
TABLE 3 sample scratch test results
Sample numbering
First critical load (Lc 1)
Second critical load (Lc 1)
B-PCT
1.28N
15.97N
A/B-PCT
4.64N
17.22N
