SmVO4 / HMOR composite photocatalytic material as well as preparation method and application thereof

Abstract

The invention discloses a SmVO4 / HMOR composite photocatalytic material and a preparation method and application thereof.The preparation method comprises the steps that samarium oxide is put into a beaker, a nitric acid solution is added in the stirring state, samarium nitrate mixed liquor is obtained after the samarium oxide is dissolved through heating, the samarium nitrate mixed liquor is dried, and Sm (NO3) 36H2O is obtained; the preparation method comprises the following steps: mixing a Sm (NO3) 36H2O aqueous solution with hydrogen mordenite, stirring at 80 DEG C for 60 minutes, adding an NH4VO3 solution to form a reaction solution, adjusting the pH value of the reaction solution to 7 by using ammonia water, reacting for 2 hours, filtering, taking a solid, and calcining for 2 hours to obtain the SmVO4 / HMOR composite photocatalytic material. According to the invention, highly dispersed SmVO4 nanoparticles are prepared on the surface of HMOR through a precipitation method, and the SmVO4 / HMOR composite photocatalytic material with high photocatalytic activity is synthesized; the HMOR serving as the carrier solves the problem of agglomeration of the SmVO4 nano-particles, the HMOR serving as the carrier has excellent supporting performance and stability, the SmVO4 nano-particles are kept firm on the surface of the HMOR, and the prepared photocatalytic material has cycling stability.

Description

Technical Field

[0001] The invention belongs to the technical field of functional materials and relates to a composite photocatalytic material, and specifically relates to a SmVO4 / HMOR composite photocatalytic material and a preparation method and application thereof. Background Art

[0002] RhB (Rhodamine B), which has a bright pink color and good stability, is often used as a fluorescent dye in the industrial field. However, high molecular weight RhB will accumulate in large quantities in organisms, seriously affecting the ecological balance. At present, adsorption, chemical oxidation, Fenton method, electrochemical oxidation and photocatalysis are usually used to degrade RhB. Among them, photocatalysis technology has been highly valued as a green and environmentally friendly purification technology. The photocatalytic method shows unique advantages in removing toxic and harmful organic pollutants, and can oxidize and decompose pollutants into H2O, CO2 and other non-toxic components. Therefore, the degradation of RhB by photocatalysis has certain environmental significance.

[0003] Metal vanadates have attracted wide attention due to their good chemical and thermal stability. Vanadates have high UV absorption cross sections, which are conducive to the transfer of absorbed energy. Vanadium-based rare earth photocatalysts have been widely studied in the fields of optics, electricity and catalysis. However, the easy aggregation and low specific surface area of ​​samarium vanadate hinder its application in the field of photocatalysis. Summary of the invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a SmVO4 / HMOR composite photocatalytic material with cycle stability and high catalytic reaction rate, and a preparation method and application thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0007] Step 1, put 5g of samarium oxide into a beaker, add 12mL of 35wt% nitric acid solution under stirring, heat to 60°C to dissolve the samarium oxide, and after dissolution, obtain a samarium nitrate mixed solution, dry and grind the samarium nitrate mixed solution to obtain Sm(NO3)3·6H2O;

[0008] Step 2: Mix the Sm(NO3)3·6H2O aqueous solution prepared in step 1 with hydrogen-type mordenite, stir at 80°C for 60 minutes, add NH4VO3 solution to form a reaction solution, adjust the pH of the reaction solution to 7 with ammonia water, stir the reaction at 80°C for 2 hours, filter, wash and dry the solid, and then calcine the solid at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material;

[0009] Among them, the mass concentration of Sm(NO3)3·6H2O aqueous solution is 20.28%;

[0010] The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1;

[0011] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 5.96-53.65wt%.

[0012] The present invention also has the following technical features:

[0013] Preferably, the drying in step 1 is to place the samarium nitrate mixture in an oven and dry it at 60° C. for 12 to 24 hours.

[0014] Preferably, the mass concentration of the ammonia water in step 2 is 25wt%.

[0015] Preferably, the washing in step 2 is washing with deionized water for 3 to 5 times.

[0016] Preferably, the drying in step 2 is performed at 80° C. for 12 to 24 hours.

[0017] The present invention also protects a SmVO4 / HMOR composite photocatalytic material prepared by the method as described above and its application in photocatalytic degradation of RhB.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] The present invention prepares highly dispersed SmVO4 nanoparticles on the surface of HMOR by a precipitation method, and synthesizes a SmVO4 / HMOR composite photocatalytic material with high photocatalytic activity; HMOR as a carrier solves the problem of SmVO4 nanoparticle agglomeration, and as a carrier has excellent support and stability, and the SmVO4 nanoparticles are firmly maintained on the surface of HMOR, and the prepared photocatalytic material has cyclic stability; the adsorption effect of HMOR can enrich RhB, increase the contact between reactants and active sites, and can also serve as an electron acceptor to inhibit the recombination of carriers, promote the reaction of electrons and O2, enhance the separation efficiency of electron-hole pairs of SmVO4 nanoparticles on its surface, inhibit the recombination of photogenerated carriers, is conducive to the generation of photocatalytic active substances, and simultaneously improves the photocatalytic reaction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the synthesis of SmVO4 / HMOR composite photocatalytic material;

[0021] Figure 2 X-ray diffraction spectra of the products prepared in Examples 1 to 5;

[0022] Figure 3 is the Fourier transform infrared spectrum of the product prepared in Example 3;

[0023] Figure 4 The XPS spectrum of the product prepared in Example 3;

[0024] Figure 5 The scanning electron microscope images of the products prepared in Examples 1 to 5;

[0025] Figure 6 is the adsorption-desorption isotherm curve of the product prepared in Example 3;

[0026] Figure 7 This is a photocatalytic degradation RhB diagram of the products prepared in Examples 1 to 5 and Comparative Example 1. DETAILED DESCRIPTION

[0027] The specific contents of the present invention are further explained in detail below in conjunction with embodiments.

[0028] Example 1

[0029] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0030] Step 1, 5 g of samarium oxide is put into a beaker, 12 mL of a 35 wt% nitric acid solution is added under stirring, and the solution is heated to 60° C. to dissolve the samarium oxide. After the dissolution is completed, a samarium nitrate mixed solution is obtained. The samarium nitrate mixed solution is put into an oven and dried at 60° C. for 12 h to obtain a block solid. The block solid is ground into powder to obtain Sm(NO3)3·6H2O;

[0031] Step 2: The Sm(NO3)3·6H2O prepared in step 1 is prepared into a 20.28% aqueous solution and mixed with hydrogen-type mordenite. After stirring at 80°C for 60 minutes, NH4VO3 is added to form a reaction solution. The pH of the reaction solution is adjusted to 7 with 25wt% ammonia water. After stirring for 2 hours at 80°C, the reaction is filtered. The solid is washed with deionized water for 3 times and dried at 80°C for 12 hours. The solid is then calcined at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material. The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1.

[0032] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 5.96wt%.

[0033] Example 2

[0034] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0035] Step 1, 5g of samarium oxide is put into a beaker, 12mL of 35wt% nitric acid solution is added under stirring, and the solution is heated to 60°C to dissolve the samarium oxide. After the dissolution is completed, a samarium nitrate mixed solution is obtained. The samarium nitrate mixed solution is put into an oven and dried at 60°C for 18h to obtain a block solid. The block solid is ground into powder to obtain Sm(NO3)3·6H2O;

[0036] Step 2: The Sm(NO3)3·6H2O prepared in step 1 is prepared into a 20.28% aqueous solution and mixed with hydrogen-type mordenite. After stirring at 80°C for 60 minutes, NH4VO3 is added to form a reaction solution. The pH of the reaction solution is adjusted to 7 with 25wt% ammonia water. After stirring for 2 hours at 80°C, the reaction is filtered. The solid is washed with deionized water 4 times and dried at 80°C for 18 hours. The solid is then calcined at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material. The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1.

[0037] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 17.89wt%.

[0038] Example 3

[0039] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0040] Step 1, 5g of samarium oxide is put into a beaker, 12mL of 35wt% nitric acid solution is added under stirring, and the solution is heated to 60°C to dissolve the samarium oxide. After the dissolution is completed, a samarium nitrate mixed solution is obtained. The samarium nitrate mixed solution is put into an oven and dried at 60°C for 24h to obtain a block solid. The block solid is ground into powder to obtain Sm(NO3)3·6H2O;

[0041] Step 2: The Sm(NO3)3·6H2O prepared in step 1 is prepared into a 20.28% aqueous solution and mixed with hydrogen-type mordenite. After stirring at 80°C for 60 minutes, NH4VO3 is added to form a reaction solution. The pH of the reaction solution is adjusted to 7 with 25wt% ammonia water. After stirring for 2 hours at 80°C, the reaction is filtered. The solid is washed with deionized water 5 times and dried at 80°C for 24 hours. The solid is then calcined at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material. The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1.

[0042] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 29.81wt%.

[0043] Example 4

[0044] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0045] Step 1, 5 g of samarium oxide is placed in a beaker, 12 mL of a 35 wt% nitric acid solution is added under stirring, and the solution is heated to 60° C. to dissolve the samarium oxide. After the dissolution is completed, a samarium nitrate mixed solution is obtained. The samarium nitrate mixed solution is placed in an oven and dried at 60° C. for 16 hours to obtain a block solid. The block solid is ground into powder to obtain Sm(NO3)3·6H2O;

[0046] Step 2: The Sm(NO3)3·6H2O prepared in step 1 is prepared into a 20.28% aqueous solution and mixed with hydrogen-type mordenite. After stirring at 80°C for 60 minutes, NH4VO3 is added to form a reaction solution. The pH of the reaction solution is adjusted to 7 with 25wt% ammonia water. After stirring for 2 hours at 80°C, the reaction is filtered. The solid is washed with deionized water 5 times and dried at 80°C for 16 hours. The solid is then calcined at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material. The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1.

[0047] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 41.74wt%.

[0048] Example 5

[0049] A method for preparing a SmVO4 / HMOR composite photocatalytic material comprises the following steps:

[0050] Step 1, 5 g of samarium oxide is put into a beaker, 12 mL of a 35 wt% nitric acid solution is added under stirring, and the solution is heated to 60° C. to dissolve the samarium oxide. After the dissolution is completed, a samarium nitrate mixed solution is obtained. The samarium nitrate mixed solution is put into an oven and dried at 60° C. for 20 h to obtain a block solid. The block solid is ground into powder to obtain Sm(NO3)3·6H2O;

[0051] Step 2: The Sm(NO3)3·6H2O prepared in step 1 is prepared into a 20.28% aqueous solution and mixed with hydrogen-type mordenite. After stirring at 80°C for 60 minutes, NH4VO3 is added to form a reaction solution. The pH of the reaction solution is adjusted to 7 with 25wt% ammonia water. After stirring for 2 hours at 80°C, the reaction is filtered. The solid is washed with deionized water 5 times and dried at 80°C for 20 hours. The solid is then calcined at 500°C in an air atmosphere for 2 hours to obtain a SmVO4 / HMOR composite photocatalytic material. The molar ratio of NH4VO3 to Sm(NO3)3·6H2O is 1:1.

[0052] In the prepared SmVO4 / HMOR composite photocatalytic material, the mass percentage of SmVO4 is 53.65wt%.

[0053] Comparative Example 1

[0054] Preparation of SmVO4 as a photocatalytic material, the synthesis steps of SmVO4 include:

[0055] 0.5 g of samarium nitrate is dissolved in 20 mL of deionized water, and 0.18 g of ammonium metavanadate is dissolved in 15 mL of ammonia water, and the two solutions are heated to 60° C. to obtain a samarium nitrate aqueous solution and an ammonium metavanadate aqueous solution; the mass concentration of the ammonia water is 25 wt %; the samarium nitrate aqueous solution and the ammonium metavanadate aqueous solution are mixed to obtain a mixed solution, and the pH of the mixed solution is adjusted to 7 with ammonia water, the color of the mixture changes from yellow to light yellow, and a large amount of precipitation begins to appear, the mixed solution containing the precipitate is stirred at 80° C. for 2 hours, filtered, and washed with deionized water for 5 times to obtain a yellow powder; the yellow powder is dried in an oven at 80° C. for 24 hours, and then calcined at 500° C. for 2 hours to obtain SmVO4.

[0056] The different SmVO4 / HMOR composite photocatalytic materials prepared in Examples 1 to 5 were characterized and compared with standard SmVO4 and HMOR. The obtained X-ray diffraction spectra are as follows: Figure 2 shown. Figure 2 (a) X-ray diffraction patterns of different SmVO4 / HMOR composite photocatalytic materials at 2θ=1-40° and (b) at 2θ=20-35°.

[0057] Depend on Figure 2 (a) Observation: The locations of the characteristic peaks of all SmVO4 / HMOR composites correspond to the standard SmVO4 tetragonal phase (JCPDS17-0876) and HMOR zeolite phase (JCPD 83-1675), respectively, proving the successful preparation of both SmVO4 and HMOR materials. It can be seen that the crystal planes (110), (020), (200), (220), (330), (150), (202) and (440) corresponding to HMOR in the SmVO4 / HMOR composite photocatalytic material have good crystallinity, indicating that the HMOR zeolite framework has not been destroyed or collapsed, proving that during the synthesis process, ions of other materials did not enter the framework of the zeolite molecular sieve. In addition, hydrogen-type mordenite is difficult to exchange with rare earth metal ions because the radius of rare earth samarium ions is 0.09nm. After entering the framework, it will cause the HMOR framework to distort. Severe distortion will lead to the formation of quartz phase. Therefore, samarium ions cannot enter the internal framework of mordenite. Figure 2 (b) It can be seen that the peaks corresponding to 2θ=24.48° and 33.00° are the characteristic peaks of SmVO4, which are consistent with the tetragonal SmVO4 phase and correspond to the (200) and (112) crystal planes, respectively. With the increase of SmVO4 content, the characteristic peaks of SmVO4 corresponding to the crystal planes in the SmVO4 / HMOR composite material gradually increase.

[0058] The SmVO4 / HMOR composite photocatalytic material prepared in Example 3 was characterized and compared with SmVO4 and HMOR. The Fourier transform infrared spectrum obtained was as follows: Figure 3 shown.

[0059] from Figure 3 It was observed that SmVO4 / HMOR at 810 cm -1 The vibration peak at 1225 cm-1 belongs to the symmetric stretching vibration of the metal-oxygen tetrahedron in the primary unit of the HMOR crystal. In the SmVO4 / HMOR composite photocatalytic material, the characteristic absorption peak of HMOR is at 1225 cm-1. -1 Around 650cm, which belongs to the antisymmetric stretching vibration of metal-oxygen tetrahedron; -1 The absorption peak at 1636 cm is attributed to the vibration of the oxygen ring channel within the framework. -1 The Si-OH bond is attributed to HMOR; and 960 cm -1 The infrared absorption peaks near can be used as direct evidence of heteroatoms entering the zeolite framework, but Figure 2 No relevant infrared absorption peaks were found near this region, proving that the metal samarium did not enter the HMOR skeleton. After comparison, the characteristic infrared spectrum of HMOR in the SmVO4 / HMOR composite material is basically consistent with the infrared spectrum of HMOR, and no new absorption peaks appear, indicating that no heteroatoms enter the HMOR skeleton, which is consistent with the results of XRD analysis.

[0060] The different SmVO4 / HMOR composite photocatalytic materials prepared in Example 3 were characterized and compared with SmVO4 and HMOR. The XPS spectra obtained are shown in Figure 4 shown; Figure 4 (a) is the XPS full spectrum of 29.81wt% SmVO4 / HMOR, Figure 4 (b) is the fine spectrum of Sm3d. Figure 4 (c) is the fine spectrum of V2p, Figure 4 (d) Fine spectrum of O1s;

[0061] Figure 4 (e) 2 is the comparison of Sm3d fine spectra of 29.81wt% SmVO4 / HMOR and SmVO4. Figure 4 (f) Comparison of V2p fine spectra of 29.81wt% SmVO4 / HMOR and SmVO4.

[0062] exist Figure 4 In (a), elements such as Sm, V, O, Si and Al in HMOR and SmVO4 can be observed; the species state on the surface of HMOR molecular sieve can be better understood through high-resolution spectra; Figure 4In (b), the peaks of 29.81wt% SmVO4 / HMOR composite at 1083.5eV and 1110.0eV can be seen, which are attributed to 3d5 / 2 and 3d3 / 2 of Sm, respectively; Figure 4 The peaks of 516.5 eV and 524.5 eV in (c) correspond to 2p3 / 2 and V2p1 / 2 of V, respectively, proving the presence of Sm and V in the composite material; Figure 4 As shown in (d), the peaks at 529.5eV and 532.1eV correspond to the Sm-O and VO bonds in the SmVO4 tetragonal lattice, which are composed of VO4 tetrahedron and SmO8. These results prove the successful synthesis of SmVO4; the peak at 532.8eV is attributed to the Si-O of HMOR; the above results are consistent with Figure 2 The XRD results are consistent with those of , proving the successful synthesis of SmVO4 / HMOR composites. Figure 4 (e, f) It is found that the energy spectrum signal of 29.81wt% SmVO4 / HMOR is enhanced, which indirectly indicates that the surface properties of the photocatalytic material containing HMOR zeolite molecular sieve are more active, proving that SmVO4 and HMOR have higher activity after composite. In addition, the V2p signal of SmVO4 / HMOR has a certain offset, and the 2p1 / 2 and 2p3 / 2 of V are slightly offset from 525.3eV and 517.3eV to 524.5eV and 516.5eV, respectively, indicating that the interaction between V and other atoms leads to a decrease in binding energy, proving that the stability of the material is enhanced; the above results show that the synthesized 29.81wt% SmVO4 / HMOR composite material is not a simple mechanical mixture, and the SmVO4 grown on the HMOR surface is tightly bound to the HMOR carrier and there is a mutual force.

[0063] Experimental Example 4

[0064] Scanning electron microscope (SEM):

[0065] The morphology and pore structure of the different SmVO4 / HMOR composite photocatalytic materials prepared by Examples 1 to 5 were characterized and compared with SmVO4 and HMOR. The SEM images obtained are as follows: Figure 5 As shown: Figure 5 (a) Scanning electron micrographs of HMOR and SmVO4 / HMOR composite photocatalysts at different concentrations (b) 5.96wt%, (c) 17.89wt%, (d) 29.81wt%, (e) 41.74wt% and (f) 53.65wt%.

[0066] like Figure 5As shown in the figure, the surface of HMOR containing SmVO4 nanoparticles becomes rough, and there is a certain space between these SmVO4 nanoparticles. Although some SmVO4 nanoparticles cover the pores of HMOR, these spaces between independently dispersed SmVO4 nanoparticles can still play the porous adsorption characteristics of HMOR. The number of SmVO4 nanoparticles on the surface of HMOR increases with the increase of SmVO4 loading. At 29.81wt%, there is a highly independent dispersion state, which is very beneficial for photocatalytic reactions. However, when the SmVO4 content exceeds 29.81wt%, SmVO4 nanoparticles begin to agglomerate on the surface of HMOR. Compared with aggregated SmVO4, highly dispersed SmVO4 nanoparticles on the surface of HMOR have higher reactivity and a larger contact area with the reactants.

[0067] The morphology and pore structure of the SmVO4 / HMOR composite photocatalytic material prepared in Example 3 were characterized and compared with SmVO4 and HMOR. The adsorption-desorption isotherm curves were shown in Fig. Figure 6 shown.

[0068] Figure 6 (ac) is the adsorption-desorption isotherm diagram, Figure 6 (d) is the pore size distribution diagram.

[0069] like Figure 6 As shown in (ac), 29.81wt% SmVO4 / HMOR shows a type IV isotherm similar to that of HMOR, indicating that the SmVO4 / HMOR composite photocatalytic material has a good porous structure like HMOR, proving that the SmVO4 nanoparticles generated on the HMOR surface will not affect the mesoporous structure of HMOR. After the introduction of SmVO4, the adsorption amount of the 29.81wt% SmVO4 / HMOR composite material decreased. This is because after the SmVO4 species grow on the HMOR surface, part of the HMOR pores are covered, reducing the adsorption amount, which indirectly proves that the SmVO4 nanoparticles are in close contact with the HMOR surface. The hysteresis loop of the 29.81wt% SmVO4 / HMOR composite material under relative pressure is consistent with that of HMOR, indicating that the 29.81wt% SmVO4 / HMOR composite still maintains a uniform pore structure. From Figure 6 As can be seen in (d), the pore size distribution of SmVO4 is not uniform, and the larger pore size is attributed to the agglomeration of SmVO4 itself and the accumulation of nanoparticles. The 29.81wt% SmVO4 / HMOR composite photocatalytic material has a uniform pore size distribution, which is because the SmVO4 nanoparticles on the HMOR surface are independently dispersed, which is consistent with the SEM results analyzed above.

[0070] The photocatalytic degradation of RhB was tested on the different SmVO4 / HMOR composite photocatalytic materials prepared in Examples 1 to 5. All samples were placed in a dark environment before the photocatalytic reaction to allow them to reach adsorption and desorption equilibrium for RhB. After 1 hour of dark reaction, the synthesized samples were tested for photocatalytic degradation of RhB. The results are as follows Figure 7 shown.

[0071] Figure 7 (a) The photocatalytic activity of SmVO4 / HMOR with different SmVO4 contents under visible light drive and (b) the kinetic constant for RhB degradation, (c) the degradation efficiency of the composite photocatalytic material, (d) the photocatalytic degradation effect of 29.81wt% SmVO4 / HMOR composite photocatalytic material on RhB under different environments (30% H2O2).

[0072] like Figure 7 (a) shows the photocatalytic activity of SmVO4 / HMOR with different contents on RhB under visible light irradiation for 2.5h. Compared with SmVO4, the degradation rate of 29.81wt% SmVO4 / HMOR increased from 33.28% to 71.29% under visible light irradiation. At the same time, it can be seen in the dark reaction process that the photocatalytic material composited with HMOR has a higher removal rate than the pure phase material, indicating that the porous advantage of HMOR is conducive to the enrichment of pollutants. Figure 7 (b) It can be seen that the photocatalytic reaction rate constant increases from 0.17 h -1 Improved to 0.50h -1 , which increased by 2.9 times, indicating that when SmVO4 and HMOR are combined, the photocatalytic efficiency of the material can be significantly improved. Figure 7 As shown in (c), the visible light degradation rate of RhB solution without catalyst is only 1.28%. As the content of SmVO4 increases, the degradation rate of RhB by SmVO4 / HMOR composite photocatalytic material increases. However, when the content of SmVO4 is greater than 29.81wt%, the degradation rate decreases with the increase of content. This is because excessive SmVO4 will form aggregates on the surface of HMOR. The agglomerated SmVO4 will form a large number of carrier recombination centers, resulting in an increase in the recombination rate of photogenerated carriers, which is not conducive to the photocatalytic reaction. Independent SmVO4 nanoparticles highly dispersed on the surface of HMOR have higher photocatalytic efficiency than their aggregates. The materials prepared by combining different contents of SmVO4 with HMOR can improve the photocatalytic performance of the materials, indicating that HMOR has the characteristics of an electron acceptor in the system, which has an attractive effect on the photogenerated electrons generated in SmVO4, prolongs the recombination time of photogenerated carriers, inhibits the recombination of photogenerated carriers of SmVO4, is conducive to the generation of photocatalytic active substances, and improves the catalytic efficiency of the photocatalytic system.

[0073] With the addition of H2O2, it is more conducive to the generation of active free radicals. Figure 7 As shown in (d), when 3.71wt% H2O2 (30%) is added to the photocatalytic system, the photocatalytic degradation rate of RhB reaches 93.26% within 30 minutes, with a faster response time and higher reaction rate. This is because H2O2 is a strong oxidizing substance, which is usually used as an electron capture agent in the photocatalytic process. It can capture photogenerated electrons, thereby separating electron-hole pairs and further improving the photocatalytic activity. Under visible light irradiation, H2O2 reacts with the conduction band electrons (e-CB) and valence band holes (h-CB) in SmVO4 on the HMOR surface. + VB) to generate active hydroxyl radicals (·OH) and superoxide radicals (·O 2- ), light-induced ·O 2- By + The reaction generates OH and OH - , photoactive substances further degrade RhB.

[0074] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A SmVO 4 / HMOR composite photocatalytic material preparation method, It is characterized in that The following steps are involved: Step 1: 5 g of samarium oxide was placed in a beaker, and 12 mL of a 35 wt% nitric acid solution was added under stirring, and the solution was heated to 60° C. to dissolve the samarium oxide. After the dissolution was completed, a samarium nitrate mixed solution was obtained, and the samarium nitrate mixed solution was dried and ground to obtain Sm(NO 3 ) 3 6H 2 O; Step 2: Sm(NO 3 ) 3 6H 2 O aqueous solution was mixed with hydrogen-type mordenite, stirred at 80 °C for 60 min, and then NH 4 VO 3 The solution was added to form a reaction solution, and the pH of the reaction solution was adjusted to 7 with ammonia water. After stirring at 80°C for 2 hours, the reaction solution was filtered, the solid was washed and dried, and the solid was calcined at 500°C in an air atmosphere for 2 hours to obtain SmVO 4 / HMOR composite photocatalytic material; Among them, Sm(NO 3 ) 3 6H 2 The mass concentration of O aqueous solution is 20.28%; NH 4 VO 3 With Sm(NO 3 ) 3 6H 2 The molar ratio of O is 1:1; The prepared SmVO 4 In the SmVO / HMOR composite photocatalyst, 4 The mass percentage is 5.96~53.65wt%.

2. The SmVO according to claim 1 4 / HMOR composite photocatalytic material preparation method, It is characterized in that The drying in step 1 is to put the samarium nitrate mixed solution into an oven and dry it at 60° C. for 12 to 24 hours.

3. The SmVO according to claim 1 4 / HMOR composite photocatalytic material preparation method, It is characterized in that The mass concentration of the ammonia water described in step 2 is 25wt%.

4. The SmVO according to claim 1 4 / HMOR composite photocatalytic material preparation method, It is characterized in that The washing in step 2 is washing with deionized water for 3 to 5 times.

5. The SmVO according to claim 1 4 / HMOR composite photocatalytic material preparation method, It is characterized in that The drying in step 2 is performed at 80° C. for 12 to 24 hours.

6. SmVO prepared by the method according to any one of claims 1 to 5 4 / HMOR composite photocatalytic materials.

7. A SmVO as claimed in claim 6 4 Application of / HMOR composite photocatalytic materials in photocatalytic degradation of RhB.

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