A method for preparing BiCa2VO6 materials with rod-like structures in a short time

Abstract

This invention belongs to the field of inorganic non-metallic material preparation technology, and discloses a method for preparing BiCa2VO6 material with a rod-like structure in a short time. Using CaCO3, Bi(NO3)3, and V2O5 as raw materials, NaCl and KCl are mixed and ground with the above raw materials as a mixed molten salt to obtain a precursor. The precursor is heat-treated at 700-850ºC for 20 min-3 h, and after natural cooling, a BiCa2VO6-salt mixture is obtained. The mixture is washed multiple times with deionized water to remove the salt components, filtered, and dried to obtain the BiCa2VO6 material. The preparation time of the BiCa2VO6 material in this invention is short and energy consumption is low. The obtained material has a significant rod-like structure with a diameter of 0.7-8 μm and a length of 6-56 μm. The preparation conditions of this method are simple and controllable, the operation process is convenient, and it is easy to achieve large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of inorganic non-metallic material preparation technology, and relates to a method for preparing BiCa2VO6 material with a rod-like structure in a short time. Background Technology

[0002] Micro / nanomaterials, as an important material system bridging atoms / molecules and macroscopic matter, have attracted widespread attention due to their unique structural features and physicochemical properties. When the size of materials is reduced to the nanoscale, their crystal structure and surface electronic states undergo significant changes, leading to quantum size effects, surface and interface effects, quantum tunneling effects, and dielectric confinement effects not present in ordinary materials. This results in micro / nanomaterials exhibiting a series of superior electrical, magnetic, optical, and thermal properties compared to conventional materials, leading to their widespread application in energy, medicine, environment, chemical catalysis, and optoelectronics. Especially in recent years, with the rapid development of micro / nanotechnology, micro / nanomaterials with precisely controllable morphology and structure have become a hot topic in materials science research due to their unique performance characteristics. For example, rod-shaped 4ZnO·B2O3·H2O micron-sized materials have good flame retardant properties and a strong promoting effect on the char formation of poplar wood powder, especially in high-temperature zones; rod-shaped molybdenum trioxide micron-sized materials are excellent photocatalysts that can greatly shorten the catalytic reaction time in a flowing system, and the introduction of oxygen can not only increase the decolorization rate of dyes but also make the dye degradation more thorough; rod-shaped cerium oxide micron-sized materials can be used as catalyst supports or active components for catalyst preparation and catalytic reaction promotion.

[0003] BiCa2VO6 possesses nonlinear optical properties, photocatalytic properties, magnetic properties, and microwave dielectric properties, making it valuable for applications in energy conversion and storage, environmental remediation, information functional devices, and microwave dielectric ceramics. The microwave dielectric properties of BiCa2VO6 were first reported in the paper "Characterization and microwave dielectric properties of BiCa2VO6ceramic" (LiC, Xiang H, Luo H, et al. Journal of Materials Science: Materials in Electronics, 2015, 26(12):9546-9551). It is a potential candidate material for low-temperature co-fired ceramics (LTCC) technology and has significant research value and application potential in the field of microwave dielectric ceramics. In modern chemistry and materials science, the microstructure of materials has a significant impact on their physical and chemical properties. Therefore, this invention prepares micron-sized BiCa2VO6 materials with a rod-like structure, which not only affects the physicochemical properties of the material but also provides possibilities for expanding the applications of BiCa2VO6 in other fields.

[0004] Currently, the preparation of BiCa2VO6 materials all employs the traditional solid-state method, which involves ball milling and mixing the raw materials followed by prolonged high-temperature calcination to obtain BiCa2VO6 powder. This method results in BiCa2VO6 powder with high preparation temperatures, long processing times, and irregular microstructures. In the literature "Synthesis, low temperature co-firing, and microwave dielectric properties of two ceramics BiM2VO6(M=Cu, Ca)" (Xie HD, Chen C, Xi HH, et al. Ceramics International, 2016, 42(1):989-995), the raw materials need to be ground and then calcined twice at 850℃ for a total of 8 hours to obtain the corresponding powder. However, there are few reports on the preparation of BiCa2VO6 materials with rod-like structures under short preparation cycles and low temperatures. Therefore, researching the preparation of BiCa2VO6 materials with specific morphologies under low calcination temperatures and short calcination times has significant application value.

[0005] This invention employs a novel approach to prepare BiCa2VO6 materials with a rod-like structure. This method enables the preparation of regularly morphologically regular rod-shaped BiCa2VO6 materials at low temperatures and in a short time, exhibiting good dispersibility. Even with prolonged high-temperature reactions, the rod-shaped BiCa2VO6 materials do not break down, maintaining their morphology well, and the preparation temperature range is wide. The preparation method is simple and controllable, with straightforward operation and easy scalability for mass production; therefore, this invention has significant application value. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing BiCa2VO6 materials with rod-like structures in a short time. This method has a simple preparation process, a wide preparation temperature range, a short preparation time, and can reduce energy consumption and process costs. It is easy to achieve large-scale production and can solve the problems of existing methods, such as long preparation time, lack of fixed morphology of products, and easy breakage of products even if they occasionally have regular morphology due to long high-temperature reaction.

[0007] The technical solution of this invention is as follows: A BiCa2VO6 material with a rod-like structure, having a diameter of 0.7-8 μm and a length of 6-56 μm.

[0008] A method for preparing BiCa2VO6 material with a rod-like structure in a short time includes the following steps: (1) CaCO3, Bi(NO3)3 and V2O5 were weighed as raw materials in a molar ratio of CaCO3:Bi(NO3)3:V2O5=4:2:1, and NaCl and KCl were weighed as mixed molten salts and ground together with the above raw materials to obtain a precursor. In the mixed molten salt, the molar ratio of NaCl:KCl=1:1. (2) The precursor obtained in step (1) is transferred to a box-type resistance furnace and heat-treated in an air atmosphere. After the reaction is completed, it is naturally cooled to obtain a BiCa2VO6-salt mixture. (3) The BiCa2VO6-salt mixture obtained in step (2) is washed multiple times with deionized water to remove the salt components. After filtration and drying, BiCa2VO6 material is obtained.

[0009] Furthermore, in step (1), the molar ratio of raw materials to mixed molten salt is: CaCO3:BiN3O9:V2O5:(NaCl-KCl)=4:2:1:(6-30).

[0010] Furthermore, in step (2), the heat treatment temperature is 700-850℃ and the time is 20min-3h.

[0011] The beneficial effects of this invention are: 1. This invention employs a novel preparation method, which can prepare BiCa2VO6 material by heat treatment at 700℃ for 2 hours or at 725℃ for 20 minutes. Compared with the traditional solid-state method, this method can reduce the material preparation temperature, shorten the preparation cycle, and reduce energy consumption.

[0012] 2. The BiCa2VO6 material prepared by this invention has a significant rod-like structure with a diameter ranging from 0.7 to 8 μm and a length ranging from 6 to 56 μm. It also exhibits good dispersibility and a wide preparation temperature range.

[0013] 3. The rod-shaped BiCa2VO6 material prepared by this invention does not break during long-term high-temperature reactions, such as above 800℃, even 2 hours at 850℃, and maintains its rod-shaped morphology well.

[0014] 4. The preparation method of the present invention has the advantages of simple operation, easy control of conditions, high purity of the obtained material and regular crystal morphology, and is easy to realize large-scale production. Attached Figure Description

[0015] Figure 1 The image shows the XRD pattern of the BiCa2VO6 material prepared in Example 1.

[0016] Figure 2 The XRD patterns of the BiCa2VO6 materials prepared in Examples 2, 3, and 4 are shown below: where a is the XRD pattern of the BiCa2VO6 material prepared in Example 2, b is the XRD pattern of the BiCa2VO6 material prepared at 750℃ in Example 3, and c and d are the XRD patterns of the BiCa2VO6 materials prepared at 800℃ and 850℃ in Example 4, respectively.

[0017] Figure 3 The XRD patterns of the BiCa2VO6 materials prepared in Examples 5 and 6 are shown below: e and f are the XRD patterns of the BiCa2VO6 materials prepared in Example 5 for 20 min and 30 min, respectively, and g and h are the XRD patterns of the BiCa2VO6 materials prepared in Example 6 for 1 h and 3 h, respectively.

[0018] Figure 4 The XRD pattern of the BiCa2VO6 material prepared in Example 7 is shown below: where i and j are the XRD patterns of the BiCa2VO6 materials prepared in ratios of 4:2:1:6 and 4:2:1:30, respectively.

[0019] Figure 5 The image shows the XRD pattern of the material prepared in Example 8.

[0020] Figure 6 This is a SEM image of the rod-shaped BiCa2VO6 material prepared in Example 1.

[0021] Figure 7 This is a SEM image of the rod-shaped BiCa2VO6 material prepared in Example 2.

[0022] Figure 8 This is a SEM image of the rod-shaped BiCa2VO6 material prepared at 750℃ in Example 3.

[0023] Figure 9 The image shows a SEM image of the rod-shaped BiCa2VO6 material prepared in Example 5 with a reaction time of 30 min.

[0024] Figure 10 The following are SEM images of the rod-shaped BiCa2VO6 materials prepared in Examples 4 and 6: (a) is the SEM image at 800℃ in Example 4, (b) is the SEM image at 850℃ in Example 4, (c) is the SEM image at 1h in Example 6, and (d) is the SEM image at 3h in Example 6.

[0025] Figure 11 The following are SEM images of the rod-shaped BiCa2VO6 material prepared in Example 7: (a) is the SEM image of CaCO3:BiN3O9:V2O5:(NaCl-KCl)=4:2:1:6, and (b) are the SEM images of CaCO3:BiN3O9:V2O5:(NaCl-KCl)=4:2:1:30. Detailed Implementation

[0026] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0027] Example 1: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 725℃ for 2 hours. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material with a diameter of 1.5~7.5μm and a length of 15~36μm.

[0028] Example 2: The difference between this embodiment and Example 1 is that the heat treatment temperature is 700℃, and the specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 700℃ for 2 hours. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material with a diameter of 1~2.6μm and a length of 6~14.5μm.

[0029] Example 3: The difference between this embodiment and embodiments 1-2 is that the heat treatment temperatures are 750℃ and 775℃. The specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 750℃ for 2 hours. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material with a diameter of 3~5μm and a length of 15~56μm.

[0030] The preparation steps were the same as above, except that the heat treatment temperature was changed to 775℃, and another rod-shaped BiCa2VO6 material was obtained.

[0031] Example 4: The difference between this embodiment and embodiments 1-3 is that the heat treatment temperatures are 800℃, 825℃, and 850℃, respectively, and the specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 min to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 800℃ for 2 h. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 h to obtain rod-shaped BiCa2VO6 material with a diameter of 1.7~6.9 μm and a length of 18~35 μm.

[0032] The preparation steps were the same as above, except that the heat treatment temperature was changed to 825℃ and 850℃, and two rod-shaped BiCa2VO6 materials were obtained respectively. The rod-shaped materials obtained at 850℃ had a diameter of 2~7μm and a length of 11.5~28μm.

[0033] Example 5: The main difference between this embodiment and embodiments 1-4 is that the reaction times are 20 min, 30 min, and 50 min, respectively. The specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 725℃ for a reaction time of 20 minutes. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material.

[0034] The preparation steps were the same as above, except that the reaction time was changed to 30 min and 50 min, and two rod-shaped BiCa2VO6 materials were obtained respectively. The rod-shaped materials obtained in 30 min had a diameter of 1.9~6.5 μm and a length of 9~29 μm.

[0035] Example 6: The main difference between this embodiment and embodiments 1-5 is that the reaction times are 1 hour and 3 hours, respectively. The specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 725℃ for 1 hour. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material with a diameter of 0.7~3μm and a length of 7~23μm.

[0036] The preparation steps were the same as above, except that the reaction time was changed to 3 hours, and a rod-shaped BiCa2VO6 material was obtained with a diameter of 0.9~3.6μm and a length of 7.7~25μm.

[0037] Example 7: The main difference between this embodiment and Examples 1-6 is that the molar ratio of the raw materials is CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:6, 4:2:1:12, 4:2:1:24, and 4:2:1:30. The specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:6, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 725℃ for 2 hours. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain rod-shaped BiCa2VO6 material with a diameter of 2~4.9μm and a length of 14~27μm.

[0038] The preparation steps were the same as above, except that the molar ratio of the raw materials was changed to 4:2:1:12, 4:2:1:24 and 4:2:1:30, and three rod-shaped BiCa2VO6 materials were obtained. The rods with a ratio of 4:2:1:30 had a diameter of 1.4~8μm and a length of 15~27.4μm.

[0039] Example 8: The main difference between this comparative example and Examples 1-7 is that the calcination temperature is 650℃, and the specific preparation method is as follows: Using a molar ratio of CaCO3:Bi(NO3)3:V2O5:(NaCl-KCl)=4:2:1:18, CaCO3, Bi(NO3)3, and V2O5 were weighed as raw materials, and corresponding amounts of NaCl and KCl were added as a mixed molten salt (with a molar ratio of NaCl:KCl=1:1) and mixed with the above raw materials and ground for 8 minutes to obtain a precursor. The obtained precursor was transferred to a box-type resistance furnace and heat-treated in air atmosphere at a temperature of 650℃ for 2 hours. After the reaction time was completed, it was naturally cooled to obtain a BiCa2VO6-salt mixture. The obtained BiCa2VO6-salt mixture was washed multiple times with deionized water to remove the salt components, filtered, and dried at 114℃ for 1.8 hours to obtain the product.

[0040] Figure 1-4 The XRD patterns of the materials prepared in Examples 1-7 are shown. It can be seen from the XRD patterns that the diffraction peaks of the products obtained under the conditions of the examples are high and no impurity peaks are present, indicating that highly crystalline BiCa2VO6 materials have been generated.

[0041] Figure 5 The image shows the XRD pattern of the material prepared in Example 8. Analysis showed that the product prepared in Example 8 was not a BiCa2VO6 phase.

[0042] Figure 6-11 The images show SEM images of the BiCa2VO6 materials prepared in Examples 1-7. These SEM images show that rod-shaped BiCa2VO6 materials were obtained, with diameters ranging from 0.7-8 μm and lengths ranging from 6-56 μm.

[0043] The foregoing has shown and described the basic principles and main features of the present invention, but the above are only specific embodiments of the present invention. The technical features of the present invention are not limited thereto. All changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A method for preparing BiCa2VO6 material with a rod-like structure in a short time, characterized in that, Includes the following steps: (1) CaCO3, Bi(NO3)3 and V2O5 were weighed as raw materials in a molar ratio of CaCO3:Bi(NO3)3:V2O5=4:2:1, and NaCl and KCl were weighed as mixed molten salts and ground together with the above raw materials to obtain a precursor. In the mixed molten salt, the molar ratio of NaCl:KCl=1:

1. (2) The precursor obtained in step (1) is transferred to a box-type resistance furnace and heat-treated in an air atmosphere. After the reaction is completed, it is naturally cooled to obtain a BiCa2VO6-salt mixture. (3) The BiCa2VO6-salt mixture obtained in step (2) is washed multiple times with deionized water to remove the salt components. After filtration and drying, BiCa2VO6 material is obtained.

2. The method for preparing BiCa2VO6 material with a rod-like structure in a short time according to claim 1, characterized in that, In step (1), the molar ratio of raw materials to mixed molten salt is: CaCO3:BiN3O9:V2O5:(NaCl-KCl)=4:2:1:(6-30).

3. The method for preparing BiCa2VO6 material with a rod-like structure in a short time according to claim 1, characterized in that, In step (2), the heat treatment temperature is 700-850℃ and the time is 20min-3h.

4. The method for preparing BiCa2VO6 material with a rod-like structure in a short time according to claim 1, characterized in that, This BiCa2VO6 material has a distinct rod-like structure with a diameter of 0.7-8 μm and a length of 6-56 μm.

Images