Long-afterglow base composite photocatalytic material, and preparation method and application thereof

Abstract

The application discloses a long-afterglow-based composite photocatalytic material and a preparation method and application thereof, and the preparation method comprises the following steps: taking a certain mass of SrCO3, MgO, SiO2, Eu2O3, Dy2O3 and H3BO3 respectively, putting them into a ball mill to be fully ground and mixed, taking them out and putting them into a high-temperature tube-type sintering furnace, heating to 1000-1300 DEG C, grinding again after cooling, adding alcohol, ultrasonic washing, drying, and obtaining SMSO; dissolving ZnCl2, InCl3 and C2H5NS in deionized water, adding the SMSO, pouring into a reaction kettle, then keeping at 100-300 DEG C for 5-15 h, cooling, washing with deionized water after centrifugation, drying, grinding, and obtaining the composite photocatalytic material SMSO-ZIS. The composite photocatalytic material disclosed by the application can keep stable sterilization function under light and dark state, and can be reused.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photocatalysis, in particular to a long-afterglow-based composite photocatalytic material and a preparation method and application thereof. BACKGROUND

[0002] With the development of marine economy and the exploitation and utilization of marine resources, marine biofouling has gradually become one of the most important factors affecting the safe development of marine ports, warships, coastal power plants, oil drilling platforms and other facilities. Biofouling and pollution can cause an increase in the load of structures, especially an increase in the sailing resistance of mobile facilities such as ships, an increase in energy consumption, a decrease in sailing speed and other serious problems. At present, the most commonly used method is antifouling paint, but the additives generally have high toxicity, which can easily cause drug resistance and biological safety problems of marine fouling organisms, so it is urgent to develop efficient and environmentally friendly biofouling control technology.

[0003] The photocatalytic process is a redox process. When the photocatalyst is irradiated with light having an energy greater than or equal to its band gap, the electrons on the valence band (VB) of the photocatalytic material will be excited and transition to the conduction band (CB), and the generated electrons and holes will react with H2O, OH-, O2 and other substances on the surface of the catalyst to produce strong oxidizing active radicals. Photogenerated electrons, holes and radicals will participate in the degradation of organic matter and the inactivation of microorganisms. Marine biofouling refers to the attachment of marine fouling organisms on the surface of marine engineering facilities, which secretes harmful substances and causes different types of damage to the engineering facilities. Among them, the microorganisms adsorbed on the surface of marine facilities are the basis of large-scale biofouling. If effective sterilization is performed during the initial attachment stage of microorganisms, it will be beneficial to control marine biofouling and pollution. However, photocatalytic materials can only function under light conditions, which greatly limits the application of photocatalysts in actual marine environments. Therefore, how to solve the problem that photocatalytic materials cannot function in dark environments has become a top priority in the research of photocatalytic antifouling. SUMMARY

[0004] To solve the above technical problems, the present application provides a long-afterglow-based composite photocatalytic material and a preparation method and application thereof, so as to achieve the purpose of exerting photocatalytic effect under lightless conditions.

[0005] To achieve the above purpose, the technical solutions of the present application are as follows:

[0006] A preparation method of a long-afterglow-based composite photocatalytic material, comprising the following steps:

[0007] (1) Preparation of SMSO:

[0008] Take a certain mass of SrCO3, MgO, SiO2, Eu2O3, Dy2O3, H3BO3 respectively, put them into a ball mill and mix them thoroughly for 10-60 min, take them out and put them into a crucible, and put them into a high-temperature tube sintering furnace, heat them to 1000-1300℃ under a reducing atmosphere, and keep them at this temperature for 1-4 h, cool them to room temperature, grind them again, then add alcohol to the powder, ultrasonic wash for 20-60 min to make the powder uniformly dispersed, and finally dry the powder in an oven at 60-140℃ to obtain Sr2MgSi2O7:Eu 2+ ,Dy 3 + , namely SMSO;

[0009] (2) Preparation of SMSO-ZIS:

[0010] Dissolve ZnCl2, InCl3 and C2H5NS in a molar ratio of 1:2:4 in deionized water, stir until they are all dissolved, then add SMSO and continue stirring, then pour into a tetrafluoroethylene-lined reaction kettle, then keep at 100-300℃ for 5-15 h, then naturally cool to room temperature, wash several times with deionized water after centrifugation, and dry at 60-90℃, take out and grind thoroughly to obtain Sr2MgSi2O7:Eu 2+ ,Dy 3+ ZnIn2S4 composite photocatalytic material, namely SMSO-ZIS.

[0011] In step (1) of the above scheme, the molar ratio of SrCO3, MgO, SiO2, Eu2O3, Dy2O3, H3BO3 is 1.96:1:2:0.01:0.01:0.1.

[0012] In step (1) of the above scheme, the heating rate is 5-10℃ / min and the cooling rate is 2-6℃ / min.

[0013] In step (1) of the above scheme, grind and mix in the ball mill for 60 min.

[0014] In step (1) of the above scheme, heat to 1200℃ in the high-temperature tube sintering furnace for 2 h.

[0015] In step (1) of the above scheme, dry the powder in an oven at 60℃.

[0016] In step (2) of the above scheme, keep at 200℃ in the reaction kettle for 12 h.

[0017] In step (2) of the above scheme, dry at 60℃.

[0018] A long afterglow-based composite photocatalyst material SMSO-ZIS prepared by the method described above.

[0019] Application of the long afterglow-based composite photocatalyst SMSO-ZIS as described above in the fields of water purification and marine fouling control.

[0020] The long afterglow-based composite photocatalytic material, its preparation method, and its application provided by the above technical solution have the following beneficial effects:

[0021] This invention is the first to use Sr2MgSi2O7:Eu 2+ ,Dy 3+ When combined with ZnIn2S4, the resulting composite material exhibits durable bactericidal and degradation properties, overcoming the limitation of ordinary photocatalytic materials that cannot function in the dark. This is of great significance for promoting the application of photocatalytic materials in marine antifouling.

[0022] Specifically, it includes:

[0023] (1) This invention is the first to use an in-situ growth method to grow ZnIn2S4 with long afterglow material Sr2MgSi2O7:Eu 2+ ,Dy 3+ The combination method is simple, easy to control, and low in cost;

[0024] (2) Sr2MgSi2O7:Eu prepared in this invention 2+ ,Dy 3+ -ZnIn2S4 composite photocatalytic materials have good visible light absorption performance;

[0025] (3) Sr2MgSi2O7:Eu prepared in this invention 2+ ,Dy 3+ -ZnIn2S4 composite photocatalyst material, relative to pure Sr2MgSi2O7:Eu 2+ ,Dy 3+ The composite material significantly improved the bactericidal performance of Escherichia coli and the degradation performance of methyl orange under both light and dark conditions. The bactericidal rate of the composite material reached 27% after 1 hour of visible light irradiation and 43% after 6 hours of dark conditions. Under simulated sunlight, the degradation rate of methyl orange was 72% after 5 minutes of light irradiation and 39% after 6 hours of dark conditions.

[0026] (4) The long afterglow-based composite photocatalytic material prepared by the present invention has good stability and reusability, and still has high photocatalytic activity after three cycles of use;

[0027] (5) The long-afterglow-based composite photocatalytic material prepared in the application has a heterojunction structure, which accelerates the separation of photo-generated carriers, reduces the recombination of carriers, and improves the sterilization and degradation performance of the photocatalytic material under light and dark state, and has great potential in the application in water purification and marine antifouling fields. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below.

[0029] Figure 1 XRD patterns of ZIS, SMSO and long-afterglow-based composite photocatalytic materials SMSO-ZIS-1, SMSO-ZIS-2 and SMSO-ZIS-3.

[0030] Figure 2 Scanning electron microscope pictures of (a) ZIS, (b) SMSO-ZIS-1, (c) SMSO-ZIS-2 and (d) SMSO-ZIS-3.

[0031] Figure 3 UV-Vis diffuse reflectance spectra of long-afterglow-based composite photocatalytic material SMSO-ZIS-1 and SMSO and ZIS.

[0032] Figure 4 Light degradation rate of methyl orange by ZIS and long-afterglow-based composite photocatalytic material SMSO-ZIS-1, C0 is the initial concentration of methyl orange, C t Methyl orange concentration when the reaction time is t.

[0033] Figure 5 Dark degradation rate of methyl orange by ZIS, SMSO and long-afterglow-based composite photocatalytic materials SMSO-ZIS-1, SMSO-ZIS-2 and SMSO-ZIS-3, C i Initial concentration of methyl orange when lighted for 5 min, C t Methyl orange concentration when the reaction time is t.

[0034] Figure 6 Sterilization curve of E. coli by ZIS and SMSO, long-afterglow-based composite photocatalytic material SMSO-ZIS-1 under light and dark state.

[0035] Figure 7 Repeated sterilization rate of long-afterglow-based composite photocatalytic material SMSO-ZIS-1. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings of the embodiments of the present application.

[0037] The present application provides a long-afterglow-based composite photocatalytic material, a preparation method and application thereof, and specifically as follows.

[0038] First, a long-afterglow material Sr2MgSi2O7:Eu 2+ ,Dy 3+ (SMSO):

[0039] 0.196 mol of SrCO3, 0.1 mol of MgO, 0.2 mol of SiO2, 0.001 mol of Eu2O3, 0.001 mol of Dy2O3 and 0.01 mol of H3BO3 are weighed, and then the weighed components are put into a ball mill for fully grinding and mixing for 60 minutes, taken out and put into a small crucible, and put into a high-temperature tube sintering furnace, heated to 1200 DEG C under a reducing atmosphere, and kept for 2 hours, wherein the heating rate is 5 DEG C / min, after the heating is completed, the natural cooling is performed to room temperature, and then grinding is performed again, and the cooling rate is 5 DEG C / min; then alcohol is added to the powder, and ultrasonic washing is performed for 30 minutes to uniformly disperse the powder, and finally, the powder is dried in an oven at 60 DEG C to obtain SMSO.

[0040] Example 1

[0041] 0.002 mol of ZnCl2, 0.004 mol of InCl3 and 0.008 mol of C2H5NS are dissolved in 30 ml of deionized water, stirred to completely dissolve, then 0.8465 g of SMSO is added, and stirring is continuously performed for 30 minutes, then loaded into a 50 ml tetrafluoroethylene lining reaction kettle, and then kept at 200 DEG C for 12 hours, and then naturally cooled to room temperature, washed several times with deionized water and anhydrous ethanol after centrifugation, and dried at 60 DEG C, taken out and fully ground and uniformly mixed to obtain a long-afterglow-based composite photocatalytic material SMSO-ZIS-1.

[0042] Example 2

[0043] 0.002 mol of ZnCl2, 0.004 mol of InCl3 and 0.008 mol of C2H5NS are dissolved in 30 ml of deionized water, stirred to completely dissolve, then 0.8465 g of SMSO is added, and stirring is continuously performed for 30 minutes, then loaded into a 50 ml tetrafluoroethylene lining reaction kettle, and then kept at 200 DEG C for 12 hours, and then naturally cooled to room temperature, washed several times with deionized water and anhydrous ethanol after centrifugation, and dried at 60 DEG C, taken out and fully ground and uniformly mixed to obtain a long-afterglow-based composite photocatalytic material SMSO-ZIS-1.

[0044] Example 3

[0045] 0.002 mol ZnCl2, 0.004 mol InCl3, 0.008 mol C2H5NS were dissolved in 30 ml deionized water, stirred to dissolve completely, then 2.5395 g SMSO was added, and stirring was continued for 30 min, then loaded into a 50 ml tetrafluoroethylene liner, then kept at 200℃ for 12 h, then naturally cooled to room temperature, washed with deionized water and anhydrous ethanol several times after centrifugation, and dried at 60℃, taken out and fully ground to uniformity, to obtain a long afterglow-based composite photocatalytic material SMSO-ZIS-3.

[0046] In order to compare the performance of the long afterglow-based composite photocatalytic material prepared in the application, a monomer ZnIn2S4(ZIS) was also synthesized, and the specific method was as follows:

[0047] 0.002 mol ZnCl2, 0.004 mol InCl3, 0.008 mol C2H5NS were respectively weighed and dissolved in 30 ml deionized water and stirred to dissolve completely, then loaded into a 50 ml tetrafluoroethylene liner, then kept at 200℃ for 12 h, then naturally cooled to room temperature, washed with deionized water and anhydrous ethanol several times after centrifugation, and dried at 60℃, taken out and fully ground to uniformity.

[0048] Performance test:

[0049] Figure 1 The XRD patterns of the long afterglow-based composite photocatalytic materials prepared in Examples 1-3, SMSO, and ZIS can be seen that the prepared SMSO and ZIS have good peak types, which respectively correspond to standard cards PDF76-1736 (tetragonal structure) and PDF65-2023 (hexagonal structure), indicating that the SMSO and ZIS materials are successfully synthesized, and the composite photocatalytic material SMSO-ZIS also has the characteristic peaks of SMSO and ZIS, without other impurity peaks, indicating that the composite photocatalytic material is composed of Sr2MgSi2O7:Eu 2+ ,Dy 3+ and ZnIn2S4.

[0050] Figure 2 The scanning electron microscope pictures of the prepared samples, Figure 2 in (a) can clearly see that the ZnIn2S4 is composed of a spherical structure of ultra-thin nanosheets, Figure 2 (b), (c), and (d) are respectively the composite photocatalytic materials prepared in Examples 1-3, and with the increase of SMSO, the sheet structure of ZIS gradually decreases, but the two can still be closely combined.

[0051] Figure 3The long afterglow-based composite photocatalytic material SMSO-ZIS-1 prepared in Example 1 and the light absorption range of SMSO and ZIS are compared, and the light absorption performance of SMSO-ZIS-1 is obviously enhanced compared with SMSO.

[0052] Application:

[0053] Application Example 1:

[0054] The photocatalytic materials ZIS and long afterglow-based composite photocatalytic material SMSO-ZIS-1 obtained above are applied to photodegradation of methyl orange:

[0055] An 800W xenon lamp is used as a light source, 50ml of methyl orange solution with a concentration of 10ppm is added to a 50ml quartz tube, then 25mg of photocatalytic material ZIS or SMSO-ZIS-1 is added, and after stirring, the photocatalytic degradation experiment is carried out, and a sample is taken every 10min during the reaction process, then the photocatalyst is centrifuged and separated, and the absorbance of methyl orange in the supernatant is detected by an ultraviolet-visible spectrophotometer to obtain the residual concentration of methyl orange and calculate the degradation rate.

[0056] From Figure 4 It can be seen that the degradation rate of long afterglow-based composite photocatalytic material SMSO-ZIS-1 is obviously improved compared with ZIS alone, which indicates that the combination of SMSO and ZIS accelerates the separation ability of photo-generated carriers and improves the photocatalytic performance of ZIS.

[0057] Application Example 2:

[0058] The ZIS, SMSO and long afterglow-based composite photocatalytic materials SMSO-ZIS-1, SMSO-ZIS-2 and SMSO-ZIS-3 obtained above are applied to dark-state degradation of methyl orange:

[0059] An 800W xenon lamp is used as a light source, 50ml of methyl orange solution with a concentration of 10ppm is added to a 50ml quartz tube, then 25mg of ZIS, SMSO or long afterglow-based composite photocatalytic material SMSO-ZIS-1, SMSO-ZIS-2 and SMSO-ZIS-3 is added, and after light irradiation for 5min, the reaction is carried out in the dark, a sample is taken every 60min during the reaction process, then the photocatalyst is centrifuged and separated, and the absorbance of methyl orange in the supernatant is detected by an ultraviolet-visible spectrophotometer to obtain the residual concentration of methyl orange and calculate the dark-state degradation rate.

[0060] From Figure 5It can be seen that compared with ZIS and SMSO materials, the long afterglow-based composite photocatalytic material SMSO-ZIS-1, SMSO-ZIS-2, SMSO-ZIS-3 still has obvious degradation function 6h after light irradiation, which shows that the photocatalytic material prepared by taking long afterglow material as a substrate has the function of continuously degrading organic dyes in dark state.

[0061] Application Example 3:

[0062] The above obtained ZIS, SMSO and long afterglow-based composite photocatalytic material SMSO-ZIS-1 are applied to continuous sterilization under visible light and in dark state:

[0063] An 800W xenon lamp is used as a light source, and a 400nm filter is used to filter out ultraviolet light, so that the wavelength is greater than 400nm. 50ml of 0.01M PBS solution is added to a 50ml quartz tube, then 25mg of photocatalytic material ZIS, SMSO or SMSO-ZIS-1 is added, and an E. coli solution is inoculated. After 60min of light irradiation, the sample is taken, the E. coli solution is diluted to a certain concentration for plate experiment, and then placed in a 37℃ oven for 24h. Then, after 6h of dark degradation, the sample is taken again, diluted and cultured with bacteria. In the experiment, each group is repeated 3 times, and then each dilution of the bacterial solution is also repeated 3 times. Finally, the average value is taken as the final result. According to the number of bacteria at different times, the sterilization rate under visible light and in dark state is calculated.

[0064] From Figure 6 It can be seen that compared with ZIS and SMSO, the long afterglow-based composite photocatalytic material SMSO-ZIS-1 has obvious improvement in sterilization function under light irradiation, and can still maintain high sterilization function in dark state.

[0065] Application Example 4:

[0066] The above obtained long afterglow-based composite photocatalytic material SMSO-ZIS-1 is repeatedly used for sterilization under visible light:

[0067] An 800W xenon lamp is used as a light source, and a 400nm filter is used to filter out ultraviolet light, so that the wavelength is greater than 400nm. 50ml of 0.01M PBS solution is added to a 50ml quartz tube, then 25mg of photocatalytic material is added, and an E. coli solution is inoculated. After 60min of light irradiation, the sample is taken, the E. coli solution is diluted to a certain concentration for plate experiment, and then placed in a 37℃ oven for 24h. Then, after 6h of dark degradation, the sample is taken again, diluted and cultured with bacteria.

[0068] After the experiment, the photocatalytic material was centrifuged, then washed with deionized water and anhydrous ethanol for several times, and dried at 60°C. The dried sample was subjected to the average sterilization under visible light and dark state for 3 cycles. Each group was repeated 3 times in the experiment, and each dilution of bacterial solution was also repeated 3 times. Finally, the average value was taken as the final result. According to the number of colonies at different times, the sterilization rate under visible light and dark state was calculated.

[0069] By Figure 7 It can be seen that the long afterglow-based composite photocatalytic material SMSO-ZIS-1 used repeatedly can still maintain stable sterilization function under light and dark state.

[0070] The above description of disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a long afterglow-based composite photocatalytic material, characterized in that, Comprising the following steps: (1) Preparation of SMSO: Take a certain mass of SrCO3, MgO, SiO2, Eu2O3, Dy2O3, H3BO3 respectively, put them into a ball mill for grinding and mixing for 10-60 min, take them out and put them into a crucible, and put them into a high-temperature tube sintering furnace, heat to 1000-1300°C under a reducing atmosphere, continue for 1-4 h, cool to room temperature again, then grind, then add alcohol to the powder, ultrasonic washing for 20-60 min, make the powder uniformly dispersed, finally, dry the powder in an oven at 60-140°C, obtain Sr2MgSi2O7:Eu 2+ ,Dy 3+ , namely SMSO; (2) Preparation of SMSO-ZIS: Dissolve 0.002 mol ZnCl2, 0.004 mol InCl3, 0.008 mol C2H5NS in deionized water, stir to dissolve them completely, then add 0.8465g SMSO and continue stirring, then pour into a tetrafluoroethylene-lined reaction kettle, then keep at 100-300℃ for 5-15h, then naturally cool to room temperature, after centrifugation, wash several times with deionized water, and dry at 60-90℃, take out and grind thoroughly, to obtain Sr2MgSi2O7:Eu 2+ ,Dy 3+ -ZnIn2S4 composite photocatalytic material, namely SMSO-ZIS.

2. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (1), the molar ratio of SrCO3, MgO, SiO2, Eu2O3, Dy2O3, and H3BO3 is 1.96:1:2:0.01:0.01:0.

1.

3. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (1), the heating rate is 5-10℃ / min, and the cooling rate is 2-6℃ / min.

4. The preparation method of a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (1), the mixture is ground in a ball mill for 60 min.

5. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (1), heat to 1200℃ in a high-temperature tube sintering furnace for 2 h.

6. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (1), dry the powder in an oven at 60℃.

7. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (2), keep the reaction kettle at 200℃ for 12 h.

8. The method for preparing a long afterglow-based composite photocatalytic material according to claim 1, characterized in that, In step (2), dry at 60℃.

9. A long-afterglow-based composite photocatalytic material SMSO-ZIS prepared by the preparation method of claim 1.

10. The use of the long-afterglow-based composite photocatalytic material SMSO-ZIS of claim 9 in the field of water purification and marine fouling control.

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