High-strength photocatalytic water purification and permeable brick and preparation method thereof

Abstract

The application discloses a kind of high-strength photocatalytic water purification water-permeable brick and preparation method thereof, comprising the following steps: uniformly mixing binder, coupling agent and curing agent, to obtain bonding component;Bonding component is added to composite aggregate, after stirring uniformly, pour into mould and be pressed into shape, to obtain water-permeable brick;Photocatalytic component is uniformly sprayed on the surface of water-permeable brick, and is taken out after curing.The application also discloses a kind of high-strength photocatalytic water purification water-permeable brick, which is prepared by the above high-strength photocatalytic water purification water-permeable brick preparation method.The high-strength photocatalytic water purification water-permeable brick and preparation method thereof provided by the application can improve the efficiency of photocatalysis by uniformly spraying photocatalytic component on the surface of water-permeable brick and taking it out after curing.

Description

TECHNICAL FIELD

[0001] The application relates to a high-strength photocatalytic water-purification permeable brick and a preparation method thereof, and belongs to the technical field of permeable bricks. BACKGROUND

[0002] At present, bricks for road paving are mainly made of impermeable materials such as granite, cement and asphalt, and when it rains, the road is seriously waterlogged, which affects people's life. At the same time, the rainwater cannot infiltrate, causing waste of water resources and a great burden on the urban drainage system. In addition, pollutants such as domestic waste and sewage will be discharged into rivers and lakes along with the precipitation, causing serious environmental pollution.

[0003] Sand-based permeable bricks have been widely used in urban roads because of their wide raw material sources, low preparation cost, good water filtration performance and good mechanical properties. However, due to the single function, it is necessary to modify the permeable bricks to improve their application fields. Patent CN111499266A uses silica sand and toughened modified epoxy resin as raw materials to prepare permeable bricks, but the compatibility between silica sand, which is an inorganic non-metallic material, and organic polymer materials such as epoxy resin still needs to be improved. Patent CN112358213A prepares a permeable material by coating the surface of silica sand, which can intercept pollutants in runoff, but the preparation cost is high, and the weather resistance is poor because the epoxy resin used contains a benzene ring structure.

[0004] Adding photocatalytic nanoparticles to permeable bricks can enhance the ability of permeable bricks to treat pollutants in water during water permeation and filtration. Graphitic carbon nitride (g-C3N4) is a non-metallic two-dimensional layered material with visible light response and low cost, which is widely used in the field of photocatalysis. Adding g-C3N4 to permeable bricks is a common method to improve the water pollution treatment ability of permeable bricks. Patent 202011567747.7 invents a fluorescent photocatalytic permeable brick, which uses carbon nitride nanosheets to prepare a suspension and directly adds it to the preparation process of the permeable brick. The photocatalytic component in the permeable brick is mainly in the interior of the permeable brick, so the photocatalytic efficiency is low. At the same time, the added carbon nitride nanosheets are in a suspension system, which may agglomerate when added to the preparation process of the permeable brick, further affecting the photocatalytic efficiency of the permeable brick. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide a high-strength photocatalytic water-purification permeable brick and a preparation method thereof. By uniformly spraying the photocatalytic component on the surface of the permeable brick and taking it out after curing, the photocatalytic efficiency can be improved.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] A high-strength photocatalytic water purification brick preparation method, comprising the following steps:

[0008] Uniformly mix the binder, coupling agent and curing agent to obtain a binding component;

[0009] Add the binding component to the composite aggregate, stir uniformly and then pour into a mold for compression molding to obtain the water permeable brick;

[0010] Uniformly spray the photocatalytic component on the surface of the water permeable brick, and take out after curing.

[0011] The composite aggregate is 100 parts by weight, the binding component is 2-6 parts by weight, and the photocatalytic component is 1-5 parts by weight.

[0012] The composite aggregate is a combination of coarse aggregate and fine aggregate, wherein the coarse aggregate of the composite aggregate is desert sand, and the fine aggregate is coated sand prepared by a hot method from the desert sand; the mesh number of the coarse aggregate is 35-50 mesh, and the mesh number of the fine aggregate is 80-100 mesh; the content of the coarse aggregate in the composite aggregate is 70-90% by weight.

[0013] The binding component comprises 100 parts by weight of the binder, 5-10 parts by weight of the coupling agent and 30-50 parts by weight of the curing agent; the binding component is obtained by stirring in a planetary gravity stirrer at a speed of 600-1200 r / min and a pressure of 30-90 kPa for 30-60 s; the binder is hydrogenated bisphenol A epoxy resin, the coupling agent is one or more of KH550, KH560 and KH570, and the curing agent is one or more of phenolic amine and low-molecular-weight polyamide.

[0014] The photocatalytic component is an oxygen-sulfur double-doped g-C3N4 dispersion liquid, which is prepared by the following method: adding oxygen-sulfur double-doped g-C3N4 nanosheets into deionized water, stirring uniformly, adding a dispersant into the oxygen-sulfur double-doped g-C3N4 nanosheet suspension to obtain a mixed solution, and then stirring the mixed solution in a magnetic stirrer for a period of time to obtain the photocatalytic component.

[0015] The concentration of the oxygen-sulfur double-doped g-C3N4 nanosheet suspension is 1-5%, and the dispersant is one or more of sodium dodecyl benzene sulfonate, cetyl trimethyl ammonium bromide, polyvinyl alcohol, dodecyl polyoxyethylene ether, 1-butyl-3-methyl imidazole tetrafluoroborate, N-propyl pyrrolidine acid salt, gelatin, carboxymethyl cellulose, polyacrylate and polystyrene acrylate; the content of the dispersant is 1-3% of the oxygen-sulfur double-doped g-C3N4 nanosheets by weight, the ultrasonic time is 10-30 min, and the magnetic stirring time is 20-40 min.

[0016] The preparation method of the oxygen-sulfur double-doped g-C3N4 nanosheet is as follows:

[0017] A certain mass of trithiocyanic acid (TCCA) is hydrothermally treated at 40-120 DEG C for a certain time to obtain trithiocyanic acid and a composite product of hydrocyanic acid and isocyanic acid (TMS), and then cooled and dried to remove the remaining trithiocyanic acid to obtain pure composite product of hydrocyanic acid and isocyanic acid;

[0018] The composite product of hydrocyanic acid and isocyanic acid is calcined at 450-600 DEG C for 2-4 h at a certain heating rate, and after calcination, centrifugal washing and drying are performed to obtain oxygen-sulfur co-doped g-C3N4 nanosheets (CNOS).

[0019] The mass of trithiocyanic acid is 10-20 g, the hydrothermal time is 6-12 h, the calcination temperature is 550 DEG C, the heating rate is 2 DEG C / min, and the drying temperature is 30-60 DEG C, and the drying time is 6-12 h.

[0020] The curing method is as follows: the water permeable brick is sent into a curing kiln, the temperature is controlled at 20-25 DEG C, the humidity is controlled at 50-70%, and curing is performed for 10-30 days.

[0021] A high-strength photocatalytic water purification water permeable brick is prepared by the high-strength photocatalytic water purification water permeable brick preparation method.

[0022] The beneficial effects of the present application are as follows:

[0023] (1) The photocatalytic component is uniformly sprayed on the surface of the water permeable brick, and is taken out after curing, and the photocatalytic component is attached to the surface of the water permeable brick, compared with the prior art in which the photocatalytic component is mainly in the water permeable brick, the contact area between the photocatalytic component and the water body can be increased, the photocatalytic efficiency can be improved, and the ability to remove pollutants in water can be improved.

[0024] (2) The present application uses a gradation of different particle size aggregates to prepare the water permeable brick, compared with the water permeable brick prepared by using a single particle size aggregate as the aggregate, the fine aggregate can fill the pores between the coarse aggregate, on the one hand, the contact area of the aggregate and the high molecular binder is increased, the mechanical strength of the water permeable brick is improved, and the service life is prolonged to a certain extent; on the other hand, the porosity of the whole water permeable brick is reduced, the pore size is reduced, the probability of blocking the pores in the filtration process is reduced, and the anti-blocking ability of the water permeable brick is improved;

[0025] (3) In the present application, coated sand and desert sand are used as aggregates to prepare the water permeable brick, compared with the water permeable brick prepared by using single desert sand as the aggregate, the coated sand has better weather resistance and corrosion resistance than the desert sand, which helps to prolong the service life of the water permeable brick; at the same time, the high molecular coating on the surface of the coated sand can improve the compatibility between the aggregate and the high molecular material to a certain extent, and the bonding strength between the high molecular binder is increased, thereby the mechanical strength and stability of the water permeable brick are improved;

[0026] (4) The present application uses hydrogenated bisphenol A epoxy resin as a high molecular binder to prepare water permeable bricks. Compared with using bisphenol A type epoxy resin as a binder, the benzene ring in the hydrogenated bisphenol A epoxy resin is replaced by a saturated six-membered ring, so it has excellent weather resistance and can prolong the service life of the water permeable brick;

[0027] (5) The oxygen-sulfur double-doped g-C3N4 nanosheet prepared in the present application contains active amino groups, which can undergo ring-opening crosslinking reaction with the epoxy groups in the hydrogenated bisphenol A epoxy resin. On the one hand, it improves the compatibility and adhesion between the oxygen-sulfur double-doped g-C3N4 nanosheet and the water permeable brick. On the other hand, the multiple crosslinking at the interface between the two phases helps to improve the compressive strength and flexural strength of the water permeable brick as a whole;

[0028] (6) In the present application, oxygen-sulfur double-doped g-C3N4 nanosheet is used. Compared with single-atom doped g-C3N4, the photocatalytic activity of oxygen-sulfur double-atom doped g-C3N4 nanosheet is not only affected by the single oxygen atom and sulfur atom alone, but also by the synergistic effect of the two atoms, and its photocatalytic activity is stronger. In addition, unlike the oxygen-sulfur double-doped g-C3N4 nanosheet obtained by mixing two or three precursors and then further processing, the oxygen-sulfur double-doped g-C3N4 nanosheet in the present application can be obtained by hydrothermal treatment and then calcination of a single precursor of trithiocyanate. This method simplifies the preparation method and cost of oxygen-sulfur double-doped g-C3N4 nanosheet, and is simple to operate;

[0029] (7) In the present application, a dispersant is used to prepare an oxygen-sulfur double-doped g-C3N4 nanosheet dispersion. Compared with the commonly used g-C3N4 nanosheet suspension, it has better dispersibility and is not easy to agglomerate during loading on the surface of the water permeable brick. In addition, the pore structure on the surface of the water permeable brick further increases the surface area of the oxygen-sulfur double-doped g-C3N4 nanosheet, improving the efficiency of photocatalytic degradation of pollutants in water. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the formation process diagram of the oxygen-sulfur double-doped g-C3N4 nanosheet (CNOS) in the present application;

[0031] Figure 2 is a comparison chart of the photocatalytic degradation of COD of the water permeable bricks prepared in the examples and the comparative examples of the present application. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application. Specific embodiment 1

[0034] 10 g of TCCA (trithiocyanic acid) was hydrothermally treated at 80 °C for 6 h to obtain TCCA and TMS (a composite product of cyanic acid and isocyanic acid) obtained by hydrolysis of TCCA, and then cooled and dried. The obtained TMS was calcined in a muffle furnace at 550 °C for 2 h at a heating rate of 2 °C / min, and finally centrifuged, washed and dried at 60 °C for 6 h to obtain CNOS (oxygen-sulfur double-doped g-C3N4 nanosheets), and the formation process of CNOS is shown in Figure 1 1 g of CNOS was added to 100 g of deionized water, stirred uniformly, and then 0.02 g of polyvinyl alcohol was added thereto. After ultrasonic treatment for 10 min, magnetic stirring was performed for 30 min to obtain a CNOS dispersion liquid.

[0035] 4 g of hydrogenated bisphenol A epoxy resin, 0.4 g of KH550 and 2 g of polyamide curing agent were added to a planetary gravity stirrer, and the rotation speed of the planetary gravity stirrer was set to 600 r / min and the pressure was set to 30 kPa. After stirring for 30 s, it was taken out and added to a mixed aggregate of 160 g of 40 mesh desert sand and 40 g of 90 mesh coated sand. After stirring uniformly, it was poured into a mold, and after compression molding, it was taken out.

[0036] 2 g of CNOS dispersion liquid was uniformly sprayed on the surface of the brick blank, and then it was placed in a curing kiln. The temperature was controlled at 20 °C and the humidity was controlled at 50%, and the photocatalytic water purification and permeable brick was obtained after curing for 20 days. Specific embodiment 2

[0038] 10 g of TCCA (trithiocyanic acid) was hydrothermally treated at 80 °C for 6 h to obtain TCCA and TMS (a composite product of cyanic acid and isocyanic acid) obtained by hydrolysis of TCCA, and then cooled and dried. The obtained TMS was calcined in a muffle furnace at 550 °C for 2 h at a heating rate of 2 °C / min, and finally centrifuged, washed and dried at 60 °C for 6 h to obtain CNOS (oxygen-sulfur double-doped g-C3N4 nanosheets), and the formation process of CNOS is shown in Figure 1 2 g of CNOS was added to 100 g of deionized water, stirred uniformly, and then 0.04 g of polyvinyl alcohol was added thereto. After ultrasonic treatment for 10 min, magnetic stirring was performed for 30 min to obtain a CNOS dispersion liquid.

[0039] 8 g of hydrogenated bisphenol A epoxy resin, 0.8 g of KH550 and 4 g of polyamide curing agent were added to a planetary gravity stirrer, and the rotation speed of the planetary gravity stirrer was set to 600 r / min and the pressure was set to 30 kPa. After stirring for 30 s, it was taken out and added to a mixed aggregate of 160 g of 40 mesh desert sand and 40 g of 90 mesh coated sand. After stirring uniformly, it was poured into a mold, and after compression molding, it was taken out.

[0040] Spray 6 g CNOS dispersion liquid evenly on the surface of the brick, and then put it into the curing kiln, control the temperature at 20℃, humidity 50% for 20 days, and then the photocatalytic water purification brick is obtained. Example 3

[0042] 10 g TCCA (trithiocyanic acid) was hydrothermally treated at 80℃ for 6 h to obtain a composite product of TCCA and cyanic acid and isocyanic acid (TMS) obtained by hydrolysis of TCCA, and then cooled and dried. The obtained TMS was calcined in a muffle furnace at 550℃ for 2 h with a heating rate of 2℃ / min, and finally centrifuged, washed and dried at 60℃ for 6 h to obtain CNOS (oxygen-sulfur co-doped g-C3N4 nanosheets). The formation process of CNOS is shown in Figure 1 2 g CNOS was added to 100 g deionized water, stirred evenly, and then 0.04 g polyvinyl alcohol was added. After ultrasonic treatment for 10 min, magnetic stirring was carried out for 30 min to obtain a CNOS dispersion liquid.

[0043] 10 g hydrogenated bisphenol A epoxy resin, 1 g KH550 and 5 g polyamide curing agent were added to a planetary gravity stirrer, and the rotation speed of the planetary gravity stirrer was set to 600 r / min and the pressure was 30 kPa. After stirring for 30 s, it was taken out and added to a mixture of 160 g 40 mesh desert sand and 40 g 90 mesh coated sand. After stirring evenly, it was poured into a mold, and after compression molding, it was taken out.

[0044] 8 g CNOS dispersion liquid was sprayed evenly on the surface of the brick, and then it was put into the curing kiln, and the temperature was controlled at 20℃, humidity 50% for 20 days, and then the photocatalytic water purification brick was obtained.

[0045] Comparative Example 1

[0046] 10 g hydrogenated bisphenol A epoxy resin, 0.5 g KH560 and 3 g polyamide curing agent were added to a planetary gravity stirrer, and the rotation speed of the planetary gravity stirrer was set to 600 r / min and the pressure was 30 kPa. After stirring for 30 s, it was taken out and added to 500 g 40 mesh desert sand. After stirring evenly, it was poured into a mold, and the brick was compression molded. The brick was taken out and put into a curing kiln, and the temperature was controlled at 20℃, humidity 50% for 20 days, and then the water permeable brick was obtained.

[0047] Comparative Example 2

[0048] Mix 5 g of urea and 2 g of oxalic acid dihydrate, and grind for 0.5 h. Put the ground powder into a crucible, and calcine at a temperature raising rate of 5 ℃ / min to 550 ℃ in an air atmosphere, and keep the temperature for 2 h to obtain CNO (oxygen-doped g-C3N4 nanosheets). Take 2 g of CNO, add it to 100 g of deionized water, stir until uniform, and then add 0.04 g of polyvinyl alcohol to the mixture. Ultrasonic for 10 min, and then stir magnetically for 30 min to obtain a CNO dispersion liquid.

[0049] Put 4 g of hydrogenated bisphenol A epoxy resin, 0.4 g of KH550, and 2 g of polyamide curing agent into a planetary gravity stirrer, set the rotation speed of the planetary gravity stirrer to 600 r / min, and the pressure to 30 kPa. Stir for 30 s, take out, and add to a mixture of 160 g of 40-mesh desert sand and 40 g of 90-mesh coated sand. Stir until uniform, and then pour into a mold. After compression molding, take out.

[0050] Uniformly spray 2 g of the CNO dispersion liquid on the surface of the brick blank, and then put it into a curing kiln. Control the temperature at 20 ℃ and the humidity at 50%, and cure for 20 days to obtain a photocatalytic water purification and permeable brick.

[0051] Comparative Example 3

[0052] Take 5 g of melamine precursor, and put it into a mortar. Then add 1 g of thiourea, mix and grind for a period of time until uniform. Then put the mixture into a porcelain crucible, cover, and put into a muffle furnace. Set the temperature raising rate to 5 ℃ / min, and raise the temperature to 600 ℃. Keep the temperature for 4 h. When the temperature of the muffle furnace decreases to room temperature, take it out and grind to obtain a light yellow powder sample, that is, CNS (sulfur-doped g-C3N4 nanosheets).

[0053] Take 2 g of CNS, add it to 100 g of deionized water, stir until uniform, and then add 0.04 g of polyvinyl alcohol to the mixture. Ultrasonic for 10 min, and then stir magnetically for 30 min to obtain a CNS dispersion liquid.

[0054] Put 4 g of hydrogenated bisphenol A epoxy resin, 0.4 g of KH550, and 2 g of polyamide curing agent into a planetary gravity stirrer, set the rotation speed of the planetary gravity stirrer to 600 r / min, and the pressure to 30 kPa. Stir for 30 s, take out, and add to a mixture of 160 g of 40-mesh desert sand and 40 g of 90-mesh coated sand. Stir until uniform, and then pour into a mold. After compression molding, take out.

[0055] Uniformly spray 2 g of the CNS dispersion liquid on the surface of the brick blank, and then put it into a curing kiln. Control the temperature at 20 ℃ and the humidity at 50%, and cure for 20 days to obtain a photocatalytic water purification and permeable brick.

[0056] The materials prepared in each example were tested, and the performance data are shown in Table 1.

[0057] Table 1 Performance data of high-strength photocatalytic water purification brick

[0058] Sample Compressive strength / MPa Flexural strength / MPa 24 h COD degradation / % Example 1 36.9 3.68 45.74 Example 2 40.3 4.57 55.38 Example 3 42.5 5.12 67.01 Comparative Example 1 30.2 3.09 0 Comparative Example 2 33.4 3.26 40.14 Comparative Example 3 33.9 3.31 42.52

[0059] As shown in Table 1, compared with Comparative Example 1, the water permeable bricks prepared in the present application have significantly improved compressive strength and flexural strength, because the coated sand and desert sand are used as aggregate in the present application to prepare the water permeable bricks, and compared with the water permeable bricks prepared by using single desert sand as aggregate, the coated sand has better weather resistance and corrosion resistance, which helps to prolong the service life of the water permeable bricks; at the same time, the high molecular coating on the surface of the coated sand can improve the compatibility between the aggregate and the high molecular material to some extent, and improve the bonding strength between the high molecular binder, thereby improving the mechanical strength and stability of the water permeable bricks.

[0060] Figure 2 CNO-1 and CNS-1 represent the photocatalytic water purification bricks prepared in Comparative Example 2 and Comparative Example 3, respectively, and CNOS-1, CNOS-3 and CNOS-4 represent the photocatalytic water purification bricks prepared in Specific Example 1, Specific Example 2 and Specific Example 3, respectively (wherein the component-number after the dash indicates the % content of the dispersion in the water permeable brick, such as 1 indicating that the mass of the dispersion is 1% of the water permeable brick). As shown in Table 1 and Figure 2 As shown in Table 1, compared with Comparative Example 2 and Comparative Example 3, the COD degradation rate of the water permeable bricks prepared in the present application has been significantly improved, because the oxygen-sulfur double-doped g-C3N4 nanosheet is used in the present application, and compared with the single-atom doped g-C3N4, the photocatalytic activity of the oxygen-sulfur double-atom doped g-C3N4 nanosheet is not only affected by the single oxygen atom and sulfur atom, but also affected by the synergistic effect of the two atoms, and the photocatalytic activity is stronger.

[0061] In addition, compared with Comparative Example 2 and Comparative Example 3, the strength of the water permeable bricks prepared in the present application has also been partially improved, because the oxygen-sulfur double-doped g-C3N4 nanosheet prepared in the present application contains active amino groups, which can undergo ring-opening crosslinking reaction with the epoxy groups in the hydrogenated bisphenol A epoxy resin, on the one hand, improving the compatibility and bonding force between the oxygen-sulfur double-doped g-C3N4 nanosheet and the water permeable brick, and on the other hand, the multiple crosslinking effect at the interface of the two phases helps to improve the compressive strength and flexural strength of the water permeable brick as a whole; in addition, the nanolayer thickness of the oxygen-sulfur double-doped g-C3N4 nanosheet prepared in the present application is lower, and the number of amino groups exposed on the surface is more than that of the single-atom doped g-C3N4 nanosheet, and the improvement of the strength of the water permeable brick is more significant.

[0062] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. A method for preparing high-strength photocatalytic permeable water purification bricks, characterized in that: Includes the following steps: The binder, coupling agent, and curing agent are uniformly mixed to obtain a bonding component. By weight, the bonding component contains 100 parts of binder, 5-10 parts of coupling agent, and 30-50 parts of curing agent. The binder is hydrogenated bisphenol A epoxy resin, the coupling agent is one or more of KH550, KH560, and KH570, and the curing agent is one or more of phenolic amine and low molecular weight polyamide. The binder is added to the composite aggregate, stirred evenly, poured into a mold, and pressed to form permeable bricks. The composite aggregate is a combination of coarse and fine aggregates. The coarse aggregate is desert sand, and the fine aggregate is coated sand prepared from desert sand by a thermal method. The mesh size of the coarse aggregate is 35-50 mesh, and the mesh size of the fine aggregate is 80-100 mesh. By weight, the coarse aggregate content in the composite aggregate is 70%-90%. The photocatalytic component was uniformly sprayed onto the surface of permeable bricks, cured, and then removed. The photocatalytic component was an oxygen-sulfur dual-doped g-C3N4 dispersion, which was prepared as follows: oxygen-sulfur dual-doped g-C3N4 nanosheets were added to deionized water and stirred evenly. Then, a dispersant was added to the oxygen-sulfur dual-doped g-C3N4 nanosheet suspension to obtain a mixed solution. The mixed solution was then sonicated for a period of time and stirred in a magnetic stirrer for a period of time to obtain the final product. The preparation method of oxygen-sulfur dual-doped g-C3N4 nanosheets is as follows: A certain mass of trithiocyanate was hydrothermally heated at 40~120°C for a certain period of time to obtain trithiocyanate and a composite product of cyanic acid and isocyanic acid, and then cooled and dried. After cooling and drying, the product was calcined in a muffle furnace at 450~600℃ for 2~4h at a certain heating rate. After calcination, it was centrifuged, washed and dried to obtain oxygen-sulfur dual-doped g-C3N4 nanosheets.

2. The method for preparing a high-strength photocatalytic permeable water purification brick according to claim 1, characterized in that: By weight, the composite aggregate is 100 parts, the binder is 2-6 parts, and the photocatalytic component is 1-5 parts.

3. The method for preparing a high-strength photocatalytic permeable water purification brick according to claim 1, characterized in that: The binder component was obtained by mixing in a planetary gravity mixer with a speed of 600~1200 r / min, a pressure of 30~90 kPa, and a mixing time of 30~60 s.

4. The method for preparing a high-strength photocatalytic permeable water purification brick according to claim 1, characterized in that: The concentration of the oxygen-sulfur co-doped g-C3N4 nanosheet suspension is 1%~5%, and the dispersant is one or more of the following: sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, polyvinyl alcohol, dodecyl polyoxyethylene ether, 1-butyl-3-methylimidazolium tetrafluoroborate, N-propylpyrrolidone, gelatin, carboxymethyl cellulose, polyacrylate, and polystyrene ester; the content of the dispersant by weight is 1%~3% of the oxygen-sulfur co-doped g-C3N4 nanosheets, the ultrasonic time is 10~30 min, and the magnetic stirring time is 20~40 min.

5. The method for preparing a high-strength photocatalytic permeable water purification brick according to claim 1, characterized in that: The mass of trithiocyanate is 10~20g, the hydrothermal time is 6~12h; the calcination temperature is 550°C, the heating rate is 2°C / min, the drying temperature is 30~60°C, and the time is 6~12h.

6. The method for preparing a high-strength photocatalytic permeable water purification brick according to claim 1, characterized in that: The curing method is as follows: send the permeable bricks into the curing kiln, control the temperature at 20~25℃ and the humidity at 50~70%, and cure for 10~30 days.

7. A high-strength photocatalytic permeable water purification brick, characterized in that: It is prepared by the method for preparing high-intensity photocatalytic permeable water purification bricks according to any one of claims 1 to 6.

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