Preparation method of silver and aluminum loaded palygorskite composite material and application thereof

Abstract

This invention discloses a method for preparing a silver- and aluminum-loaded attapulgite composite material and its application. The method involves mixing attapulgite with hydrochloric acid, reacting, drying, and grinding to obtain modified attapulgite. The modified attapulgite is then mixed with aluminum chloride solution and reacted, followed by drying to obtain aluminum-modified attapulgite. Silver nitrate, aluminum-modified attapulgite, and deionized water are mixed to obtain a mixed solution. KI solution is added dropwise to the mixed solution, and the mixture is stirred for 2–4 hours. After filtration, washing, drying, and grinding, a precursor material for the loaded material is obtained. This precursor material is then photoactivated in a photochemical reactor to obtain the silver- and aluminum-loaded attapulgite composite material Ag / AgI / Al. The Ag / AgI / Al material prepared by this invention exhibits good doping effects. Furthermore, in the composite material system, Ag, AgI, and Al produce a synergistic effect, resulting in a good degradation effect on methyl orange.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic degradation material preparation, specifically involving a method for preparing a composite material of silver and aluminum attapulgite and its application. Background Technology

[0002] With the continuous increase in entropy due to technological advancements and social activities, environmental pollution is intensifying, making the removal of organic dyes from wastewater an urgent environmental issue. The main characteristics of dyeing and printing wastewater are high COD values, large COD / BOD ratios, high molecular weight, and high color intensity. Its harmful effects include: ① high color intensity, which easily absorbs sunlight and inhibits photosynthesis in aquatic plants; ② low dissolved oxygen concentration, causing oxygen deprivation and death in aquatic organisms; ③ nitrogen- and phosphorus-containing detergents in the wastewater, leading to eutrophication; ④ high concentrations of highly toxic organic matter in the wastewater. Treatment methods for dyeing and printing wastewater include physical, chemical, and biological methods. Biological methods have a wide range of applications and can treat large volumes of wastewater. Chemical oxygen absorption methods are simple but can cause secondary pollution. Photocatalytic degradation technology, as a type of adsorption method, has the advantages of energy saving, greenness, and high efficiency and is widely studied and used.

[0003] Methyl orange is a colored and toxic azo dye; its indiscriminate discharge can damage the ecological environment, thus requiring a green and environmentally friendly solution. Attapulgite, as a green catalyst carrier, is characterized by its low cost, stable properties, high efficiency, and environmental friendliness, and has enormous development and application value.

[0004] However, currently, the degradation effect of methyl orange using only attapulgite is poor, making it difficult to apply in practice. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a composite material of silver and aluminum attapulgite.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a composite material of silver and aluminum attapulgite, comprising,

[0009] Attapulgite was mixed with hydrochloric acid, reacted, dried, and ground to obtain modified attapulgite.

[0010] The modified attapulgite was mixed with aluminum chloride solution and reacted, then dried to obtain aluminum-modified attapulgite.

[0011] Silver nitrate, aluminum-modified attapulgite, and deionized water were mixed to prepare a mixed solution. KI solution was added dropwise to the mixed solution, and the mixture was stirred for 2-4 hours. The mixture was then filtered, washed, dried, and ground to obtain the precursor of the loaded material.

[0012] The precursor material was photoactivated in a photochemical reactor to prepare the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0013] As a preferred embodiment of the preparation method described in this invention, the attapulgite clay is mixed with hydrochloric acid, wherein the mass fraction of hydrochloric acid is 5%, and the ratio of attapulgite clay to hydrochloric acid is 20g:100-200mL.

[0014] In a preferred embodiment of the preparation method described in this invention, the post-reaction drying process includes a reaction time of 2–3 h, a drying temperature of 60–80 °C, and a drying time of 60–90 min.

[0015] As a preferred embodiment of the preparation method described in this invention, the modified attapulgite clay is mixed and reacted with an aluminum chloride solution, wherein the concentration of the aluminum chloride solution is 0.5-1 mol / L, and the mass-to-volume ratio of the modified attapulgite clay to aluminum chloride is 10-20 g: 200 mL.

[0016] In a preferred embodiment of the preparation method described in this invention, the mixing reaction time is 2 to 3 hours.

[0017] In a preferred embodiment of the preparation method described in this invention, the aluminum-modified attapulgite is prepared by drying, wherein the drying temperature is 60-80°C and the drying time is 60-90 min.

[0018] In a preferred embodiment of the preparation method described in this invention, silver nitrate, aluminum-modified attapulgite, and deionized water are mixed to obtain a mixed solution, wherein the ratio of silver nitrate, aluminum-modified attapulgite, and deionized water is 100-500 mg: 2 g: 50 mL; the concentration of the KI solution is 50 g / L, and the ratio of the KI solution to silver nitrate is 20 mL: 100-500 mg.

[0019] As a preferred embodiment of the preparation method described in this invention, the photoactivation treatment includes placing 2g of the loading material precursor in a quartz test tube, adding 50mL of deionized water, placing it in a photochemical reactor, setting a 500W mercury lamp for irradiation for 30min, turning on the xenon lamp power switch, irradiating for 20min, removing it after the irradiation, washing it, drying it at 80℃ for 90min, and then grinding it to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0020] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a product from a silver and aluminum attapulgite composite material.

[0021] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of a silver and aluminum attapulgite composite material in the photocatalytic degradation of methyl orange.

[0022] Beneficial effects of this invention:

[0023] (1) This invention provides a method for preparing a composite material loaded with silver and aluminum attapulgite. Fourier transform spectroscopy analysis was used to determine the composition of the composite material. 3+ The doping makes 788.62cm -1 The characteristic peak of the O-Al bond becomes sharper, and some I- atoms form CI bonds with attapulgite, resulting in a peak at 522.06 cm⁻¹. -1 The prominent peaks indicate that the Ag / AgI / Al material is well doped.

[0024] (2) The Ag / AgI / Al material prepared by the present invention has a good doping effect. At the same time, in the composite material system, Ag, AgI and Al have a synergistic effect, which produces a good effect on the degradation of methyl orange. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0026] Figure 1 The images show SEM images of unmodified (left) and Ag / AgI / Al loaded (right) attapulgite soil in the embodiments of the present invention.

[0027] Figure 2 This is a graph showing the effect of silver nitrate loading on the degradation rate of methyl orange in the Ag / AgI / Al material in the embodiments of the present invention.

[0028] Figure 3The Fourier transform infrared spectra of the attapulgite clay, Ag-doped material, and Ag / AgI / Al-doped material of this invention are shown. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0032] The raw materials and equipment required in the embodiments of the present invention are shown in Table 1.

[0033] Table 1

[0034]

[0035]

[0036] The degradation experiment of methyl orange in this invention:

[0037] Prepare a 20 mg / L methyl orange solution. Take 50 mg of the composite catalyst into a quartz test tube and add 50 mL of 20 mg / L methyl orange solution. Turn on the main power of the fully enclosed cooling water circulation device, press and hold the power button to start the device, press the circulation button to start the circulating water, press the cooling button to start the cooling system, turn on the fan and the rotary reactor, press the power button of the rotary reactor, adjust the stirring speed and revolution speed, place the quartz test tube in the device, close the outer door, adjust the light power supply to 50V and 10A, and adjust the light exposure time to 10 min. After 10 min of dark reaction, use a plastic dropper to draw 6 mL of the supernatant into a centrifuge tube. Centrifuge for 2 min at 1000 r / min. Use a 10 mL syringe to draw the supernatant from the centrifuge tube, filter it through the membrane, and transfer it into a sampling tube. Then turn on the light source and take a sample every 10 min (six times). Pour the liquid from the sampling tube into a glass cuvette and test the absorbance of the sample at 464 nm. Record the absorbance and calculate the degradation rate.

[0038] Preparation of methyl orange standard solution:

[0039] Accurately weigh 0.1000 g of methyl orange powder onto an analytical balance and transfer it to a clean and dry 100 mL beaker. Add an appropriate amount of deionized water to completely dissolve the methyl orange powder. Use a glass rod to transfer the solution into a 1 L volumetric flask. Wash the beaker repeatedly with deionized water, transferring the washings into the volumetric flask each time with the help of the glass rod. Dilute to the mark with deionized water, shake thoroughly, and then dilute to the mark again with deionized water to prepare a 100 mg / L methyl orange standard solution for later use.

[0040] Determine the optimal wavelength:

[0041] Measure 5 mL of 100 mg / L MO standard solution into a 25 mL volumetric flask using a graduated cylinder to prepare a 20 mg / L MO standard solution.

[0042] A suitable amount of MO solution was transferred into a glass cuvette using a pipette, with deionized water as a reference. A spectrophotometer was used to perform wavelength scanning in the range of 200 nm to 1000 nm, with 20 nm intervals. The absorbance of the solution was recorded. Scanning was performed at 1 nm intervals around the peak, and the absorbance of the solution was recorded again. The data showed that the optimal measurement wavelength was determined to be 464 nm.

[0043] Determination of the standard curve:

[0044] Using a pipette, 12.50 mL, 10.00 mL, 7.50 mL, 5.00 mL, and 2.50 mL of 100 mg / L MO standard solution were transferred into five 25 mL volumetric flasks to prepare methyl orange standard solutions with concentrations of 25 mg / L, 20 mg / L, 15 mg / L, 10 mg / L, and 5 mg / L, respectively. Using deionized water as a reference, the absorbance of the five MO standard solutions at different concentrations was measured using a spectrophotometer, and the data were recorded.

[0045] Plotting the standard curve:

[0046] A standard curve was plotted with the absorbance of the solution on the horizontal axis and the concentration C (mg / L) of the solution on the vertical axis. The graph shows that the absorbance of methyl orange is directly proportional to the concentration, with the equation y = 28.79x - 0.05045 and a linear correlation coefficient R² of 0.9998. The equation shows good linearity and can be used to determine the solubility of MO.

[0047] There are many methods for analyzing the concentration of MO solution, such as titration and spectrophotometry. This experiment selects the convenient and low-cost spectrophotometric method to measure the concentration of MO solution. According to Lambert-Beer's law, a solution at low concentrations conforms to the following equation:

[0048] A = abc

[0049] In the formula, a is the absorption coefficient; b is the solution thickness; c is the solution concentration; and A is the absorbance.

[0050] In the experiment, a and b are obviously constants, therefore the absorbance of the MO solution shows a linear relationship with the solution concentration. By measuring the absorbance of the solution, the corresponding concentration can be calculated according to the standard curve. Samples are taken at 5-minute intervals, and the absorbance of the MO solution is measured. The concentration is then obtained by substituting the absorbance into the standard curve, and the degradation rate can be calculated.

[0051] The formula for calculating the degradation rate is as follows:

[0052]

[0053] In the formula, CO is the initial concentration of the MO solution (mg / L); C t — MO solution concentration at time t (mg / L); X — Degradation rate (%).

[0054] Methyl orange adsorption experiment:

[0055] Take 50 mg of each sample in a quartz test tube and add 50 mL of 20 mg / L methyl orange to each. Place the tube in a rotary reactor and take samples every 10 minutes (seven times) under dark conditions and measure the absorbance.

[0056] Example 1

[0057] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0058] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0059] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0060] (3) Take 100mg of silver nitrate, 2g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0061] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0062] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0063] Example 2

[0064] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0065] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0066] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0067] (3) Take 200mg of silver nitrate, 2g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0068] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0069] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0070] Example 3

[0071] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0072] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0073] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0074] (3) Take 300 mg of silver nitrate, 2 g of aluminum-modified attapulgite and 50 mL of deionized water, mix them and stir for 2 h to obtain a mixed solution;

[0075] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0076] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0077] Example 4

[0078] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0079] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0080] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0081] (3) Take 400 mg of silver nitrate, 2 g of aluminum-modified attapulgite and 50 mL of deionized water, mix them and stir for 2 h to obtain a mixed solution;

[0082] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0083] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0084] Example 5

[0085] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0086] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0087] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0088] (3) Take 500mg of silver nitrate, 2g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0089] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0090] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0091] SEM images of unmodified (left) and Ag / AgI / Al loaded (right) attapulgite prepared in Example 5 are shown below. Figure 1 As shown in the figure, the surface of the unloaded modified attapulgite is relatively smooth. After loading, the surface of the attapulgite changed significantly, with many fine particles distributed on the surface and in the pores, indicating that the metal and its active oxides have been distributed on the attapulgite.

[0092] The effect of silver nitrate loading on the degradation rate of methyl orange in the Ag / AgI / Al materials prepared in Examples 1-5 is shown in the following figures. Figure 2It can be seen that the degradation rate of methyl orange solution by the composite material is positively correlated with the increase of silver nitrate loading. The degradation rate increases with the increase of attapulgite loading, showing a positive correlation. Ag / AgI / Al loading has a better degradation effect.

[0093] Comparative Example 1

[0094] Prepare a 1 g / L sodium borohydride solution;

[0095] Take 500 mg of silver nitrate into a 100 mL beaker, add 2 g of attapulgite and 10 mL of deionized water, and continuously add 5 mL of sodium borohydride into the stirred beaker at a rate of 5 μg / L using a peristaltic pump under dark conditions, and stir for 20 min.

[0096] Finally, the mixture was filtered, washed, and dried in an electric hot air drying oven at 80°C for 90 minutes. It was then ground in an agate mortar and pestle for later use, thus obtaining Ag-doped attapulgite clay.

[0097] Fourier transform infrared spectra of attapulgite, Ag-doped material (prepared in Comparative Example 1), and Ag / AgI / Al-doped material (prepared in Example 5) are shown below. Figure 3 .

[0098] Analysis of the figure shows that the Ag / AgI / Al supported material, under acid-modified conditions, has a length of 1442.46 cm⁻¹. -1 The characteristic carbonate peaks at that location disappear. This is because Al... 3+ Doping, 791.54 cm -1 The absorption peak at 692.05 cm⁻¹ decreases significantly. -1 The prominent peak is due to residual Cl-. 522.16 cm⁻¹ -1 The prominent absorption peak at this point is due to the formation of CI bonds between some I- and attapulgite; the Ag-loaded material shows an absorption peak at 1442.46 cm⁻¹. -1 At this location, the aqueous environment becomes acidic under the action of sodium borohydride, causing the characteristic peaks of carbonates to become flatter.

[0099] Comparative Example 2 (without aluminum modification)

[0100] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0101] (2) Take 500 mg of silver nitrate, 2 g of modified attapulgite clay and 50 mL of deionized water, mix them and stir for 2 h to obtain a mixed solution;

[0102] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0103] (3) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / ATP.

[0104] Comparative Example 3 (Activation without light)

[0105] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0106] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0107] (3) Take 500mg of silver nitrate, 2g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0108] During this period, a 50 g / L KI solution was prepared, and 20 mL of KI solution was added dropwise to the mixed solution. The mixture was stirred for 2 hours, filtered, washed, dried at 80°C for 90 minutes, and ground to obtain the supported material, which was then used directly as a catalyst.

[0109] Comparative Example 4 (Acid-free modification)

[0110] (1) Prepare 1 mol / L aluminum chloride and add 200 mL of attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of the modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0111] (2) Take 500mg of silver nitrate, 2g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0112] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0113] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material.

[0114] Comparative Example 5

[0115] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0116] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0117] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0118] (3) Take 500mg of silver nitrate, 1g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0119] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0120] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0121] Comparative Example 6

[0122] This embodiment provides a method for preparing a composite material loaded with silver and aluminum attapulgite, the main steps of which are:

[0123] (1) Add 20g of attapulgite to 200mL of 5% hydrochloric acid, stir for 3 hours, wash, dry in an oven at 80℃ for 90 minutes, grind and set aside to obtain modified attapulgite.

[0124] (2) Prepare 1 mol / L aluminum chloride and add 200 mL of modified attapulgite to it. Stir for 2 hours, wash, dry at 80℃ for 90 minutes, and grind for later use to obtain aluminum modified attapulgite. The mass-volume ratio of modified attapulgite to 1 mol / L aluminum chloride is 20 g: 200 mL.

[0125] (3) Take 500mg of silver nitrate, 3g of aluminum-modified attapulgite and 50mL of deionized water, mix them and stir for 2h to obtain a mixed solution;

[0126] During this period, a 50 g / L KI solution was prepared, 20 mL of KI solution was added dropwise to the mixed solution, stirred for 2 h, filtered, washed, dried at 80 °C for 90 min, and ground to obtain the precursor of the loaded material.

[0127] (4) Place 2g of the loading material precursor in a quartz test tube, add 50mL of deionized water, place it in a photochemical reactor, set the mercury lamp to 500W for 30min, turn on the xenon lamp power switch, irradiate for 20min, take it out after the end, wash, dry at 80℃ for 90min, and grind to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

[0128] The effects of Comparative Examples 1-6 and Example 1 on the degradation rate of methyl orange are shown in Table 1.

[0129] Table 1

[0130] Methyl orange degradation rate (%) Example 5 90.2 Comparative Example 1 70.1 Comparative Example 2 73.6 Comparative Example 3 80.4 Comparative Example 4 82.6 Comparative Example 5 84.8 Comparative Example 6 88.3

[0131] Table 1 shows that in Comparative Example 1, Ag-doped attapulgite prepared solely by impregnation exhibited poor efficiency in degrading methyl orange. In Comparative Example 2, without the addition of aluminum-modified attapulgite, the resulting Ag / AgI / ATP composite material showed poor catalytic efficiency, possibly due to a synergistic effect between Ag, AgI, and Al to enhance catalytic performance. In Comparative Examples 3 and 4, the lack of photoactivation and acid modification resulted in decreased catalytic performance. In Comparative Example 5, the reduced amount of aluminum-modified attapulgite led to decreased catalytic performance, while the increased amount in Comparative Example 6 may be due to the excessively large Al content in the resulting Ag / AgI / Al composite product, negatively impacting the overall catalytic activity and leading to reduced catalytic efficiency.

[0132] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a composite material loaded with silver and aluminum attapulgite, characterized in that: include, Attapulgite was mixed with hydrochloric acid, reacted, dried, and ground to obtain modified attapulgite. The modified attapulgite was mixed with aluminum chloride solution and reacted, then dried to obtain aluminum-modified attapulgite. The concentration of aluminum chloride solution was 0.5-1 mol / L, the mass-to-volume ratio of modified attapulgite to aluminum chloride was 10-20 g: 200 mL, and the reaction time was 2-3 h. Silver nitrate, aluminum-modified attapulgite, and deionized water were mixed to prepare a mixed solution. KI solution was added dropwise to the mixed solution, and the mixture was stirred for 2-4 hours. After filtration, washing, drying, and grinding, the precursor material for the loaded material was obtained. The ratio of silver nitrate, aluminum-modified attapulgite, and deionized water was 100-500 mg: 2 g: 50 mL. The concentration of the KI solution was 50 g / L, and the ratio of KI solution to silver nitrate was 20 mL: 100-500 mg. 2g of the loading material precursor was placed in a quartz test tube, 50mL of deionized water was added, and the test tube was placed in a photochemical reactor. After irradiating with a 500W mercury lamp for 30min, the xenon lamp power switch was turned on and irradiated for 20min. After the irradiation was completed, the test tube was removed, washed, dried at 80℃ for 90min, and then ground to obtain the silver and aluminum attapulgite composite material Ag / AgI / Al.

2. The preparation method according to claim 1, characterized in that: The mixture of attapulgite and hydrochloric acid is wherein the mass fraction of hydrochloric acid is 5%, and the ratio of attapulgite to hydrochloric acid is 20g:100-200mL.

3. The preparation method according to claim 1 or 2, characterized in that: The reaction is followed by drying, wherein the reaction time is 2-3 hours, the drying temperature is 60-80°C, and the drying time is 60-90 minutes.

4. The preparation method according to claim 1, characterized in that: The aluminum-modified attapulgite is obtained by drying, wherein the drying temperature is 60-80℃ and the drying time is 60-90min.

5. The silver and aluminum attapulgite composite material prepared by any of the preparation methods described in claims 1 to 3.

6. The application of the silver and aluminum attapulgite composite material as described in claim 5 in the photocatalytic degradation of methyl orange.

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