A green and environmentally friendly preparation method of porous materials and the resulting products and applications

Abstract

The present invention discloses a green and environmentally friendly preparation method of a porous material and the obtained products and applications. The method prepares solid powder and liquid phosphoric acid solution, and then forms phosphate glass-ceramics particles through high-temperature molten water quenching and heat treatment, and then further processes in phosphoric acid solution to obtain a porous material. In the present invention, phosphoric acid is used to treat phosphate glass-ceramics, and a porous material is formed by selective acid etching. The phosphoric acid waste liquid after acid treatment can be recycled as a glass raw material, which greatly reduces the production cost, avoids environmental pollution, creates conditions for the large-scale industrial production of porous materials, and is a green and environmentally friendly synthesis method. In addition, the synthesized porous material has two photocatalytic functional crystal phases, does not contain significant easily decomposable crystal phases with crystals, has high thermal stability, and can be widely used in adsorption, catalytic degradation of organic pollutants, sewage treatment, photothermal catalysis, high-temperature catalysis and other fields.

Description

Technical Field

[0001] The invention relates to a green and environmentally friendly preparation method of a porous material and the obtained product, and also relates to the application of the porous material in the fields of adsorption and photocatalysis, belonging to the technical field of porous material preparation. Background Art

[0002] Porous materials have been widely used in the fields of adsorption, separation, CO2 reduction, photothermal catalysis, medium and high temperature desulfurization and denitrification catalyst carriers due to their large specific surface area, adsorption capacity and many special properties. There are many methods for synthesizing porous materials, including sol-gel method, hydrothermal synthesis method, precipitation method and chemical corrosion method. Among them, sol-gel method, hydrothermal synthesis method and precipitation method are all based on chemical reactions in solution, collectively referred to as wet chemical method, which is a bottom-up synthesis path with low production capacity, high production cost and difficulty in large-scale industrial production. Chemical corrosion method is a top-down model, usually first obtaining a certain block non-porous material, and then selectively dissolving some substances through acid chemical corrosion to form a porous skeleton material. The advantage of this method is that it can adopt industrial large-scale production methods to first prepare a large number of block non-porous materials, and then obtain porous materials through acid etching, but the disadvantage of this method is that some substances will be dissolved during the acid etching process, resulting in material waste, and acid corrosion will produce a large amount of acidic waste liquid, and subsequent recycling and treatment will incur high costs, increase production costs, and cause environmental pollution.

[0003] In the production technology of porous glass or porous microcrystalline glass, the commonly used corrosive medium is an acid solution (such as hydrochloric acid, sulfuric acid, etc.). Because glass itself is acid-resistant but not alkali-resistant, using acid as a corrosive solution can leave the glass skeleton and selectively etch away some components and structures in the glass, thereby forming a porous structure and material. However, hydrochloric acid and sulfuric acid solutions are highly corrosive and volatile, which can damage the health of production personnel. At the same time, the acid itself and the waste liquid generated during the production process can also cause serious pollution and harm to the environment. Therefore, the environmental safety of the acid etching method for preparing porous materials and the recycling and treatment of acid waste liquid have become restrictive problems in the preparation of porous materials by chemical etching, and finding a safe and alternative acid etching method has become an urgent need.

[0004] In addition, porous materials are porous skeleton structures with poor high-temperature stability. They may collapse during high-temperature use, especially when the porous skeleton itself contains crystalline water or easily decomposed substances. Once the porous structure collapses, the pores will partially or completely disappear, hindering the entry and exit of substances, and the surface area will decrease sharply. Therefore, its application in adsorption, separation, catalysis and other fields is limited. In severe cases, it will be unusable and the functions and advantages of porous materials will be completely lost. This problem is particularly prominent in the copper-titanium phosphate microcrystalline glass system with high TiO2 content. Previous studies have shown that the porous material obtained after hydrochloric acid treatment contains Ti(HPO4)2⋅2H2O crystal phase. After high-temperature calcination, the nanosheets constituting the porous structure of the material collapse completely, the pores disappear completely, and the porous structure no longer exists, losing its advantage of being used under high temperature conditions. Summary of the invention

[0005] In view of the shortcomings of the above-mentioned existing porous materials in preparation and high-temperature stability, the present invention provides a green and environmentally friendly preparation method for porous materials. The preparation method uses phosphoric acid solution as the raw material of phosphate microcrystalline glass, and uses phosphoric acid as the acid solution for acid treatment, avoiding the use of highly corrosive and volatile HCl and H2SO4 solutions, improving the safety of use, and the acid treatment uses phosphoric acid that is homologous to the glass synthesis raw material and has the same characteristics as the matrix system to be acid-etched as the etching solution. The waste liquid generated after the acid treatment can be reused as a raw material, creating conditions for the reuse of the waste liquid, and realizing the green and environmentally friendly preparation of porous materials. At the same time, the porous material obtained by the phosphoric acid treatment of the present invention has strong high-temperature stability, and still maintains the original porous structure after high-temperature calcination at 750°C, without the collapse and disappearance of the pores, and is more suitable for use under high temperature conditions.

[0006] The specific technical solutions of the present invention are as follows:

[0007] A green and environmentally friendly preparation method of a porous material, the method comprising the following steps:

[0008] (1) According to the glass formula composition of MgO-CuO-TiO2-P2O5, weigh the raw materials and mix them evenly to obtain a glass batch;

[0009] (2) Melting the glass batch materials at high temperature to obtain a glass melt, quenching the glass melt with water, and drying it to obtain a matrix glass;

[0010] (3) heating the matrix glass to the vicinity of its glass transition temperature and the first glass crystallization peak temperature in sequence to obtain heat-treated glass;

[0011] (4) The heat-treated glass is placed in a phosphoric acid solution for acid treatment, and then washed with water and dried to obtain a porous material.

[0012] Furthermore, in step (1), MgO is introduced from magnesium oxide, CuO is introduced from copper oxide, TiO2 is introduced from titanium dioxide, and P2O5 is introduced from phosphoric acid solution. There is no particular requirement for the concentration of the phosphoric acid solution, as long as the required amount of P2O5 can be introduced.

[0013] Furthermore, in step (1), in the glass formula, the molar content of MgO is 15-25%, the molar content of CuO is 20-30%, the molar content of TiO2 is 30-38%, and the molar content of P2O5 is 20-30%, and the sum of the molar contents of these four is 100%. Preferably, the molar content of MgO is 20%, the molar content of CuO is 24%, the molar content of TiO2 is 32%, and the molar content of P2O5 is 24%.

[0014] Furthermore, in step (1), the mixing order of the raw materials is: first, the magnesium oxide, copper oxide, and titanium dioxide powders are mixed evenly, and then the phosphoric acid solution is slowly added to mix into a slurry. If the mixture cannot be slurried, water is added to make the mixture slurry; after mixing evenly, the mixture is treated at 150-250°C until the water evaporates, and then crushed and fully mixed to obtain a glass batch. After heating for 20-30 hours, crushed and fully mixed to obtain a glass batch. The purpose of heating the mixture at 150-250°C is to evaporate the water in the batch to form agglomerated mud, and then grind the agglomerated mud to obtain a uniformly mixed powder batch. At the same time, mixing the raw materials evenly and then heating them will only evaporate the water, ensuring that the glass composition remains unchanged. The heating temperature can be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 21°C, 220°C, 230°C, 240°C, 250°C, preferably 200°C. The mixture is heated until it becomes agglomerated mud, and the time varies depending on the amount of water. In a specific embodiment of the present invention, the treatment time is generally 20 to 30 hours, for example 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours.

[0015] Furthermore, in step (2), the step of high-temperature melting of the glass batch material is as follows: heating the glass batch material from room temperature to 1200-1500°C at a heating rate of 3-8°C / min, and then keeping the temperature at 1200-1500°C for 1-2 hours to completely melt the batch material and obtain a glass melt. Preferably, the glass batch material is heated to 1350°C at a heating rate of 5°C / min and kept at the temperature for 1 hour.

[0016] Furthermore, in step (2), water quenching refers to pouring the obtained glass melt into water to form a glass state. The glass material after water quenching is collected and dried to obtain the mother glass.

[0017] Furthermore, in step (3), the mother glass after water quenching and drying is subjected to DTA test to obtain a DTA curve. The glass transition temperature and the first crystallization peak temperature of the glass can be obtained from the DTA curve (the glass transition temperature and the first crystallization peak temperature of the glass are two peaks in the DTA curve). The mother glass is first heated to the glass transition temperature for heat treatment for 1 to 2 hours, and then heated to near the first crystallization peak temperature of the glass for heat treatment for 2 to 3 hours, and then cooled with the furnace to obtain a heat-treated glass, which is a phosphate microcrystalline glass. If the first crystallization peak temperature of the glass is T℃, the temperature near the first crystallization peak temperature of the glass is in the temperature range of T℃ to (T+20)℃.

[0018] Furthermore, in step (3), the matrix glass is preferably heated at a heating rate of 4-5°C / min to its glass transition temperature for heat treatment, and then continued to be heated at the same heating rate to near the first crystallization peak temperature of the glass for heat treatment.

[0019] Furthermore, in step (4), the concentration of the phosphoric acid solution is 2-5 mol / L, for example, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, preferably 3 mol / L.

[0020] Furthermore, in step (4), the volume ratio of the mass of the heat-treated glass to the phosphoric acid solution is 1g:50ml~1g:200ml, for example, 1g:50ml, 1g:60ml, 1g:70ml, 1g:80ml, 1g:90ml, 1g:100ml, 1g:110ml, 1g:120ml, 1g:130ml, 1g:140ml, 1g:150ml, 1g:160ml, 1g:170ml, 1g:180ml, 1g:190ml, 1g:200ml, preferably 1g:100ml.

[0021] Furthermore, in step (4), during the acid treatment, the mixture of the heat-treated glass and the phosphoric acid solution is subjected to the acid treatment in a sealed container, the purpose of which is to prevent the phosphoric acid solution from volatilizing and to provide a certain pressure condition for the acid treatment. For example, the mixture can be placed in a container with a lid for the acid treatment, or the mixture can be placed in an open container such as a beaker, and then the container opening is sealed with a material such as a polyethylene film. Preferably, the mixture is subjected to the acid treatment in a beaker, and the beaker is sealed with 3 to 5 layers of polyethylene film.

[0022] Furthermore, in step (4), the temperature of the acid treatment is 50-100° C., for example, 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., preferably 100° C. The time required for phosphoric acid treatment is longer than that required for hydrochloric acid and sulfuric acid, and is mostly 24-96 hours, for example, 24 hours, 30 hours, 36 hours, 40 hours, 48 ​​hours, 55 hours, 60 hours, 70 hours, 80 hours, 90 hours, 96 hours, and preferably 48 hours.

[0023] Furthermore, in step (4), after the acid treatment is completed, the glass sample and the phosphoric acid waste liquid are separated, and the acid-treated glass sample is washed with water and dried to obtain the final porous material. The washing operation is: adding the acid-treated glass sample to water of equal volume to the phosphoric acid solution, soaking the glass sample for 2 to 3 hours, and then washing the glass sample with water for 3 to 5 times.

[0024] Furthermore, in step (4), the phosphoric acid waste liquid contains a large amount of phosphoric acid and also contains some Mg 2+ , Cu 2+ and Ti 4+ ions, which are the constituent elements of glass, so the phosphoric acid waste liquid can be directly reused as glass raw material in step (1). The phosphoric acid waste liquid can be used as the only raw material for P2O5, or the phosphoric acid waste liquid and pure phosphoric acid solution can be used together as the raw materials for P2O5. In this way, the waste acid solution can be recycled, the discharge of waste acid can be avoided, and the problems of waste acid pollution and post-treatment can be solved, which is more environmentally friendly. When the phosphoric acid waste liquid is reused, the P 5+ Mg 2+ , Cu 2+ and Ti 4+ The content is tested, and then the phosphoric acid waste liquid is reused as the raw material of P2O5. At the same time, the amount of Mg, Cu, and Ti introduced into the waste liquid is calculated. According to the glass formula, the amount of pure phosphoric acid solution, magnesium oxide, copper oxide, and titanium dioxide required in addition to the waste liquid is calculated, and the missing part is supplemented by these pure raw materials. There is no special requirement for the concentration of phosphoric acid waste liquid.

[0025] The preparation method of the present invention uses phosphoric acid as a glass raw material, and phosphoric acid is used as an acid solution for glass acid treatment. The phosphoric acid waste liquid after acid treatment can be reused as a glass raw material, which greatly improves the safety and green environmental protection of the preparation and reduces the preparation cost. At the same time, SEM analysis shows that the porous material obtained by phosphoric acid treatment of the present invention is a porous skeleton composed of nanosheets (see Figure 3 ). XRD analysis shows that the porous material contains two crystalline phases with photocatalytic function: MgTi4(PO4)6 and anatase TiO2 phase (see Figure 2 ), and does not contain significant Ti(HPO4) which causes thermal decomposition and pore structure collapse 2• 2H2O crystal phase, the pore structure does not collapse after calcination at 750℃ (see Figure 4 ), so the porous material has strong high temperature stability and excellent high temperature resistance, and has better advantages when used in high temperature environments.

[0026] Furthermore, the porous material of the present invention can be used as an adsorbent, a photocatalyst, etc., and therefore the use of the porous material as an adsorbent, a photocatalyst is also within the protection scope of the present invention.

[0027] Furthermore, the porous material of the present invention has good stability at high temperatures, at least at a high temperature of 750° C. Therefore, the present invention also provides the use of the porous material as a photothermal catalyst or a high-temperature catalyst carrier.

[0028] Compared with existing materials and technologies, the present invention has the following beneficial effects:

[0029] 1. In the preparation method of the porous material provided by the present invention, a phosphoric acid solution with low volatility, low corrosiveness, low environmental toxicity and homologous to the synthetic material is used as a raw material, and the phosphoric acid solution is used to corrode the phosphate microcrystalline glass matrix to form a porous material. The obtained phosphoric acid waste liquid can be reused as a raw material, thereby realizing the recovery and production reuse of production waste liquid.

[0030] 2. The preparation process of the present invention is easy to industrialize and the production process is easy to control, which is suitable for industrial preparation of porous materials. In addition, the preparation process realizes the recycling of materials, greatly reduces production costs, avoids environmental pollution, is green and environmentally friendly, and conforms to the concept of sustainable development, which is of great significance for the large-scale industrial promotion and commercial application of porous materials.

[0031] 3. The present invention adopts phosphoric acid solution as the acid treatment etchant, which changes the leaching of various elements in the phosphate microcrystalline glass and also changes the kinetics of in-situ crystal phase formation, resulting in a significant inhibition of Ti(HPO4) 2•The generation of 2H2O crystal phase improves the high-temperature stability of the generated porous material skeleton, making it more advantageous to use in high-temperature environments.

[0032] 4. The porous material obtained by the method of the present invention has two composite photocatalytic functional crystal phases and good adsorption and degradation performance, and can be widely used in the fields of adsorption, catalytic degradation of organic pollutants, sewage treatment, photothermal catalysis, high-temperature catalysis, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the DTA curve of the parent glass.

[0034] Figure 2 XRD pattern of porous materials.

[0035] Figure 3 This is a scanning electron microscope image of the porous material.

[0036] Figure 4 This is a scanning electron microscope image of the porous material after high-temperature calcination.

[0037] Figure 5 It is the N2 isotherm adsorption curve of porous materials.

[0038] Figure 6 is the concentration of Mg, Cu, Ti and P ions in the recovered acid-treated phosphoric acid solution. DETAILED DESCRIPTION

[0039] In order to make the material and technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0040] If the specific experimental conditions are not specified in the examples, they are usually based on conventional conditions or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following examples can be obtained through commercial channels unless otherwise specified.

[0041] The experimental results of the present invention are obtained by the following method: using a comprehensive thermal analyzer to perform differential thermal analysis (DTA) on the glass. Using an X-ray diffractometer, the diffraction pattern of the sample is obtained, and phase analysis is performed. Using a scanning electron microscope, the surface micromorphology of the sample is obtained. Using a nitrogen isotherm adsorption instrument to measure the N2 isotherm adsorption curve of the sample, the specific surface area is calculated according to the BET model, the pore size distribution curve is obtained according to the BJH model, and the pore size is determined by the peak point data of the curve, and the pore volume is determined by the adsorption amount at the maximum relative pressure of the N2 adsorption curve. Example 1

[0042] A method for preparing a porous material comprises the following steps:

[0043] 1. Preparation of parent glass

[0044] According to the glass formula composition of MgO-CuO-TiO2-P2O5, light magnesium oxide, copper oxide, titanium dioxide, and 85wt% phosphoric acid solution are selected as raw materials. The raw materials are accurately weighed according to the molar ratio of MgO:CuO:TiO2:P2O5=20:24:32:24. Magnesium oxide, copper oxide and titanium dioxide are first preliminarily mixed, and then 85wt% phosphoric acid solution is slowly added, and an appropriate amount of distilled water is added to mix evenly to make it present a mud state; after mixing evenly, the mixture is heated at 200℃ for 24 hours, and the water in the mixture is evaporated to form agglomerated mud, and then the mud is crushed and fully mixed to obtain a glass batch. The glass batch is loaded into an alumina crucible and melted at high temperature in a Nobadi high-temperature lifting furnace. The melting process is: the temperature is raised from room temperature to 1350℃ at a heating rate of 5℃ / min, and then kept at 1350℃ for 1 hour, so that the batch is completely melted to obtain a glass melt. After high-temperature melting, the glass melt is quickly poured into water for water quenching. The glass material after water quenching is collected and dried. This sample is the mother glass.

[0045] 2. Preparation of heat-treated glass

[0046] The matrix glass was subjected to DTA test using HCT-4 comprehensive thermal analyzer to obtain the DTA curve of the matrix glass (see Figure 1 Then a certain amount of the matrix glass in step 1 is heated to its glass transition temperature (622°C) at a heating rate of 5°C / min and heat-treated for 1 hour, and then heated to the first crystallization peak temperature of the glass (716°C) at a heating rate of 5°C / min and heat-treated for 2 hours, and then cooled in the furnace to obtain heat-treated glass.

[0047] 3. Preparation of Porous Materials

[0048] A certain amount of the heat-treated glass in step 2 and a 3 mol / L phosphoric acid solution were added to a beaker at a ratio of 1 g: 100 ml, the beaker was sealed with a three-layer polyethylene film, and then the beaker was placed in a drying oven at 100°C for acid treatment for 48 hours. After the acid treatment, the phosphoric acid solution was poured out and recovered, and then the glass sample was soaked in distilled water of the same volume as the phosphoric acid solution for 2 hours, and then the glass sample was rinsed with distilled water 3 times, and the porous material sample was obtained after drying.

[0049] XRD analysis of the porous material showed that the main crystal phase of the porous material was MgTi4(PO4)6, and it also contained anatase TiO2 crystal phase (see Figure 2 ). The SEM images of the samples are shown in Figure 3As shown, it can be seen that a large number of nanosheets grow on the surface of the sample, and the nanosheets are connected to each other to form a porous structure. The N2 adsorption isotherm of the sample shows an obvious type IV adsorption isotherm with an H3 type hysteresis loop, indicating that the sample is a mesoporous structure with pore sizes mostly distributed between 2-20nm (see Figure 5 ), the surface area and pore volume of the sample reached 16.77m 2 / g, 0.074cm 3 / g. Example 2

[0050] A method for preparing a porous material comprises the following steps:

[0051] 1. Preparation of parent glass

[0052] The concentrations of Mg, Cu, Ti and P ions in the acid-treated phosphoric acid solution recovered in Example 1 were measured using an inductively coupled plasma spectrometer (Agilent ICPOES730) (see Figure 6 ). The recovered acid-treated phosphoric acid solution is used as the raw material of P2O5, and P2O5 is completely introduced from the recovered phosphoric acid solution. According to the glass formula composition of MgO-CuO-TiO2-P2O5, the required amount of P2O5 is calculated according to the molar ratio of MgO:CuO:TiO2:P2O5=20:24:32:24. According to the calculation results, the contents of Mg, Cu, and Ti introduced together in the acid-treated phosphoric acid solution are calculated at the same time. Finally, the remaining required amounts of MgO, CuO, and TiO2 are calculated and introduced using magnesium oxide, copper oxide, and titanium dioxide.

[0053] Accurately weigh the calculated mass of magnesium oxide, copper oxide and titanium dioxide, and mix them preliminarily, then slowly add the recovered acid-treated phosphoric acid solution, and add an appropriate amount of distilled water to mix evenly to make it in a slurry state; after mixing evenly, heat the mixture at 200°C for 24 hours, evaporate the water in the mixture to form agglomerated mud, and then crush the mud and mix it thoroughly to obtain a glass batch. The glass batch is loaded into an alumina crucible and melted at high temperature in a Nobadi high-temperature lifting furnace. The melting process is: at a heating rate of 5°C / min, the temperature is raised from room temperature to 1350°C, and then kept at 1350°C for 1 hour, so that the batch is completely melted to obtain a glass melt. After the high-temperature melting is completed, the glass melt is quickly poured into water for water quenching. Collect the water-quenched glass material and dry it. This sample is the mother glass.

[0054] 2. Preparation of heat-treated glass

[0055] The matrix glass was subjected to DTA test using HCT-4 comprehensive thermal analyzer to obtain the DTA curve of the matrix glass (see Figure 1 Then a certain amount of the matrix glass in step 1 is heated to its glass transition temperature (610°C) at a heating rate of 5°C / min for 1 hour, and then the temperature is further heated to the first crystallization peak temperature of the glass (698°C) at a heating rate of 5°C / min for 2 hours, and then cooled in the furnace to obtain heat-treated glass.

[0056] 3. Preparation of Porous Materials

[0057] A certain amount of the heat-treated glass in step 2 and a 3 mol / L phosphoric acid solution were added to a beaker at a ratio of 1 g: 100 ml, the beaker was sealed with a three-layer polyethylene film, and then the beaker was placed in a drying oven at 100°C for acid treatment for 48 hours. After the acid treatment, the phosphoric acid solution was poured out and recovered, and then the glass sample was soaked in distilled water of the same volume as the phosphoric acid solution for 2 hours, and then the glass sample was rinsed with distilled water 3 times, and the porous material sample was obtained after drying.

[0058] XRD analysis of the porous material showed that the main crystal phase of the porous material was MgTi4(PO4)6, and contained anatase TiO2 crystal phase (see Figure 2 ). The SEM images of the samples are shown in Figure 3 As shown, it can be seen that a large number of nanosheets also grow on the surface of the sample, and the nanosheets are interconnected to form a porous structure. The nanosheets are thinner than the nanosheets of the sample in Example 1. The N2 adsorption isotherm of the sample shows an obvious IV-type adsorption isotherm with an H3-type hysteresis loop, indicating that the sample is also a mesoporous structure with pore sizes mostly distributed between 2-30nm (see Figure 5 ), the surface area and pore volume of the sample reached 34.18m 2 / g,0.099cm 3 / g, the surface area and pore volume of the sample are both larger than the surface area of ​​the sample obtained by direct dosing with phosphoric acid in Example 1 (16.77 m 2. g -1 ) and pore volume (0.074 cm 3. g -1 ) increases, which helps the adsorption of the dye and facilitates the subsequent photocatalysis.

[0059] The obtained porous material was calcined at 750°C for 0.5 h, and its SEM image is shown in Figure 4 As shown, it can be seen that the calcined sample still maintains the original porous structure, the surface of the nanosheets becomes rough, and new channels appear on some nanosheets.

[0060] The glass melt is synthesized again using the recovered acid-treated phosphoric acid solution, which greatly reduces the high cost of recycling and treating the acidic waste liquid and realizes the recycling of materials. At the same time, the functional crystal phase of the obtained material is the same as that in Example 1, but the number of its nanosheets is larger and thinner, and the surface area is larger, which is undoubtedly beneficial for improving material performance.

[0061] Comparative Example

[0062] Heat-treated glass was obtained according to the method of Example 1, and the heat-treated glass and 3 mol / L hydrochloric acid solution were added to a beaker at a ratio of 1 g: 100 ml. The beaker mouth was sealed with a three-layer polyethylene film, and then the beaker was placed in a 100°C drying oven for acid treatment for 13 hours and 48 hours respectively. After the acid treatment, the hydrochloric acid solution was poured out, and then the glass sample was soaked in distilled water of the same volume as the hydrochloric acid solution for 2 hours, and then the glass sample was rinsed with distilled water 3 times, and a porous material sample was obtained after drying. Among them, the sample treated with acid for 13 hours is Comparative Example 1, and the sample treated with acid for 48 hours is Comparative Example 2.

[0063] XRD analysis of the obtained porous material showed that the samples of Comparative Examples 1 and 2 contained only one photocatalytic functional crystal phase, namely, anatase TiO2 as the main crystal phase, and also contained Ti(HPO4) 2• 2H2O crystal phase (see Figure 2 ). The SEM images of the samples are shown in Figure 3 As shown, it can be seen that a large number of nanosheets grow on the surface of the sample, and the nanosheets are connected to each other to form a porous structure.

[0064] The porous material of Comparative Example 1 was calcined at 750°C for 0.5 h, and then the calcined sample was subjected to SEM analysis. The results are as follows: Figure 4 As shown in the figure, it can be seen that after calcination, due to Ti(HPO4) 2• The decomposition of the 2H2O crystal phase causes the nanosheets that make up the porous structure to collapse completely, and the pores disappear. The disappearance of the pores will greatly reduce the specific surface area and pore volume of the porous material, affecting its application.

[0065] Application Examples

[0066] In order to verify the performance of the porous material prepared by the present invention, the samples prepared in Example 2 and Comparative Example 2 were selected to perform experiments on adsorption and photocatalytic degradation of an organic dye methylene blue solution. The absorbance of the porous material before and after adsorption and photocatalytic degradation of the methylene blue solution was measured at a wavelength of 665 nm using a spectrophotometer, and the concentration of methylene blue in the solution was calculated according to the standard curve. The experimental process is as follows:

[0067] Take 50 mg of the product prepared in Example 2 and Comparative Example 2 (grinded through a 50-140 mesh standard sieve), respectively, and place them in 50 mL of a 10 mg / L methylene blue solution, and stir and adsorb in the dark until the sample reaches adsorption equilibrium. After the sample reaches adsorption equilibrium, turn on the ultraviolet light (300 W) for irradiation, and continue magnetic stirring, so that the sample degrades the methylene blue molecules in the solution under light conditions. The adsorption efficiency of the sample on methylene blue in the methylene blue solution is calculated according to the formula Calculate. In the formula, A t is the adsorption efficiency at time t, C0 is the concentration of the original solution, C t is the concentration of the solution at time t.

[0068] The results showed that after stirring for 1.5 hours in the dark, the products of Example 2 and Comparative Example 2 both reached adsorption equilibrium for the methylene blue solution, with adsorption rates of 52.04% and 47.2%, respectively. The adsorption effect of the sample of Example 2 was better than that of Comparative Example 2. After stirring for 6.5 hours under ultraviolet light, the methylene blue solutions in the products of Example 2 and Comparative Example 2 were close to clear solutions, and the total degradation rates of the products of Example 2 and Comparative Example 2 for the methylene blue dye molecules were similar, at 95.43% and 95.87%, respectively.

[0069] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A green and environmentally friendly preparation method of porous materials, characterized in that The following steps are involved: (1) According to the glass composition of MgO-CuO-TiO2-P2O5, weigh the raw materials and mix them evenly to obtain a glass batch; (2) Melting the glass batch materials at high temperature to obtain a glass melt, quenching the glass melt with water, and drying it to obtain a matrix glass; (3) heating the matrix glass to the vicinity of its glass transition temperature and the first crystallization peak temperature of the glass in sequence to obtain heat-treated glass; (4) The heat-treated glass is placed in a phosphoric acid solution for acid treatment, and then washed with water and dried to obtain a porous material.

2. The green and environmentally friendly preparation method according to claim 1, characterized in that: In step (4), the concentration of the phosphoric acid solution is 2-5 mol / L.

3. The green and environmentally friendly preparation method according to claim 1 or 2, characterized in that: In step (4), the volume ratio of the mass of the heat-treated glass to the phosphoric acid solution is 1 g:50 ml-1 g:200 ml.

4. The green and environmentally friendly preparation method according to claim 1 is characterized in that: In step (4), the mixture of the heat-treated glass and the phosphoric acid solution is subjected to an acid treatment in a sealed container.

5. The green and environmentally friendly preparation method according to claim 1 or 4, characterized in that: In step (4), the acid treatment temperature is 50-100°C and the treatment time is 24-96h.

6. The green and environmentally friendly preparation method according to claim 1 is characterized in that: In step (4), the water washing operation is as follows: adding the acid-treated glass sample into water of equal volume to the phosphoric acid solution, soaking the glass sample for 2-3 hours, and then washing the glass sample with water for 3-5 times.

7. The green and environmentally friendly preparation method according to claim 1 is characterized in that: In step (1), MgO, CuO, and TiO2 are introduced from their corresponding oxides, and P2O5 is introduced from a phosphoric acid solution.

8. The green and environmentally friendly preparation method according to claim 7, characterized in that: In step (1), in the glass formula, the molar content of MgO is 15-25%, the molar content of CuO is 20-30%, the molar content of TiO2 is 30-38%, and the molar content of P2O5 is 20-30%. The sum of the molar contents of these four is 100%.

9. The green and environmentally friendly preparation method according to claim 1 or 7, characterized in that: In step (4), after the acid treatment, the acid-treated glass sample and the phosphoric acid waste liquid are separated, and the phosphoric acid waste liquid is reused in step (1) as a raw material for glass.

10. The green and environmentally friendly preparation method according to claim 7, characterized in that: In step (1), the mixing order of the raw materials is: first, the magnesium oxide, copper oxide and titanium dioxide powders are mixed evenly, and then the phosphoric acid solution is slowly added to mix into a slurry. If the mixture cannot be slurried, water is added to make the mixture slurry; after mixing evenly, the mixture is treated at 150-250° C. until the water is evaporated, and then crushed and fully mixed to obtain a glass batch material.

11. The green and environmentally friendly preparation method according to claim 1, characterized in that: In step (2), the step of high temperature melting of the glass batch material is: heating the glass batch material from room temperature to 1200-1500°C at a heating rate of 3-8°C / min, and then keeping the temperature at 1200-1500°C for 1-2 hours to completely melt the batch material to obtain a glass melt.

12. The green and environmentally friendly preparation method according to claim 1, characterized in that: In step (3), the mother glass after water quenching and drying is heated to its glass transition temperature at a heating rate of 4-5°C / min and heat-treated for 1-2 hours, and then the temperature is further heated to near the first crystallization peak temperature of the glass and heat-treated for 2-3 hours, and then cooled in the furnace to obtain heat-treated glass; wherein the temperature near the first crystallization peak temperature of the glass is the first crystallization peak temperature of the glass or a temperature that is 20°C or less higher than the first crystallization peak temperature of the glass.

13. The porous material obtained by the green and environmentally friendly preparation method of the porous material according to any one of claims 1 to 12.

14. Use of the porous material according to claim 13 as an adsorbent, photocatalyst, photothermal catalyst or high-temperature catalyst carrier.

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