阅读说明：本技术 水热法合成尖晶石型高熵氧化物材料(MCoFeCrMn)3O4的方法 (Synthesis of spinel-type high-entropy oxide Material (MCoFeCrMn) by hydrothermal method3O4Method (2) ) 是由 高祥虎 金鹏霞 刘刚 何成玉 刘宝华 于 2021-07-19 设计创作，主要内容包括：本发明提供了一种水热法合成尖晶石型高熵氧化物材料(MCoFeCrMn)-(3)O-(4)的方法,将硝酸镍或/和硝酸铜、硝酸钴、硝酸铁、硝酸铬、硝酸锰以等摩尔充分溶解于超纯水中得到金属盐的混合溶液；再在混合溶液中加入沉淀剂搅拌均匀,然后转移至聚四氟乙烯内衬的不锈钢高压反应釜中进行水热反应,反应结束后冷却至室温,反应液经减压过滤,超纯水洗涤,抽滤分离沉淀,干燥,得到的固体粉末经晶化处理,即得到高熵氧化物(MCoFeCrMn)-(3)O-(4),其中,M=Ni或/和Cu。该高熵氧化物为尖晶石结构,在3～12μm波段具有高红外发射率,可适用于红外加热,在0.3～2.5μm波段具有高的光吸收率,可适用于太阳能吸收。(The invention provides a method for synthesizing spinel type high-entropy oxide material (MCoFeCrMn) by a hydrothermal method 3 O 4 The method comprises the steps of fully dissolving nickel nitrate or/and copper nitrate, cobalt nitrate, ferric nitrate, chromium nitrate and manganese nitrate into ultrapure water in equimolar quantities to obtain a mixed solution of metal salts; adding a precipitant into the mixed solution, stirring uniformly, transferring to a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction, cooling to room temperature after the reaction is finished, filtering the reaction solution under reduced pressure, washing with ultrapure water, filtering, separating, precipitating, drying, and crystallizing the obtained solid powder to obtain the high-entropy oxide (MCoFeCrMn) 3 O 4 Wherein M = Ni or/and Cu. The high-entropy oxide is of a spinel structure, has high infrared emissivity in a wave band of 3-12 mu m, can be suitable for infrared heating, has high light absorptivity in a wave band of 0.3-2.5 mu m, and can be suitable for solar absorptionAnd (6) harvesting.)

1. Preparation of spinel-type high-entropy oxide Material (MCoFeCrMn) by hydrothermal method₃O₄The method is that nickel nitrate or/and copper nitrate, cobalt nitrate, ferric nitrate, chromium nitrate and manganese nitrate are respectively dissolved in equimolar amountsMixing the ultrapure water and the metal salt to obtain a mixed solution of the metal salt; adding a precipitant into the mixed solution, stirring uniformly, transferring to a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction, cooling to room temperature after the reaction is finished, filtering the reaction solution under reduced pressure, washing with ultrapure water, filtering, separating, precipitating, drying, and crystallizing the obtained solid powder to obtain the high-entropy oxide (MCoFeCrMn)₃O₄Wherein M = Ni or/and Cu.

2. Hydrothermal preparation of spinel-type high-entropy oxide material (MCoFeCrMn) according to claim 1₃O₄The method of (2), characterized by: the concentration of the mixed solution is 0.1-0.6 mol/L, and the concentration of the nickel nitrate or/and copper nitrate, cobalt nitrate, ferric nitrate, chromium nitrate and manganese nitrate is 0.1-0.6 mol/L.

3. Hydrothermal preparation of spinel-type high-entropy oxide material (MCoFeCrMn) according to claim 1₃O₄The method of (2), characterized by: the precipitant is one or two of sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate.

4. Hydrothermal preparation of spinel-type high-entropy oxide material (MCoFeCrMn) according to claim 1₃O₄The method of (2), characterized by: the molar ratio of the precipitant to the total metal nitrate is 2: 1-6: 1.

5. Hydrothermal preparation of spinel-type high-entropy oxide material (MCoFeCrMn) according to claim 1₃O₄The method of (2), characterized by: the temperature of the hydrothermal reaction is 120-180 ℃, and the reaction time is 1-7 h.

6. Hydrothermal preparation of spinel-type high-entropy oxide material (MCoFeCrMn) according to claim 1₃O₄The method of (2), characterized by: the temperature of the crystallization treatment is 300-900 ℃, the temperature rising rate is 3-10 DEG/min, the heat preservation time is 2-7 h, and the temperature reduction rate is natural cooling along with the furnace.

Technical Field

The invention relates to a spinel high-entropy oxide material (MCoFeCrMn) with infrared radiation and light absorption characteristics₃O₄In particular to a method for preparing spinel by a hydrothermal methodHigh entropy oxide material (MCoFeCrMn)₃O₄(wherein, M = Ni or/and Cu) belongs to ceramic materials, and is applied to the fields of infrared heating, solar energy absorption and the like.

Background

The high-entropy oxide material is a novel ceramic material developed on the basis of high-entropy alloy, and has attracted extensive attention of researchers due to unique structural characteristics and function controllable characteristics. The high-entropy alloy is a high-grade material with stable configuration entropy-driven (FCC, BCC and the like) phase structure consisting of five or more metal elements, and has thermodynamic high-entropy effect, structural lattice distortion effect, kinetic slow diffusion effect and performance cocktail effect. The high-entropy oxide is used as a novel oxide system developed in recent years, breaks through the design concept of the traditional doped oxide, is composed of five or more metal elements in equimolar or approximately equimolar, and is widely concerned by researchers at home and abroad due to simple structure, excellent performance and the like. Juliusz Dabrowa et al prepared high entropy oxide materials (Ni, Mn, Fe, Co, Cr) having spinel structure for the first time by conventional high temperature solid phase synthesis₃O₄Specifically, NiO, MnO and Fe are mixed in an equimolar ratio₂O₃、Co₃O₄And Cr₂O₃The method adopts mechanical ball milling to mix the raw Materials uniformly and then press the mixture into small balls, then the small balls are calcined for 20 hours at 1050 ℃, and finally a sample is placed on an aluminum plate to be quenched to room temperature to prepare the high-entropy oxide (Materials Letters,2018,216: 32-36) with a single-phase spinel structure. In addition, Sarkar et al prepared rock type nanocrystalline powder by spray pyrolysis and flame pyrolysis, and then atomized and pyrolyzed by a spray device at 1150 ℃ to obtain corresponding high entropy oxide nanocrystalline powder material, and quaternary nanocrystalline powder (Co, Mg, Ni, Zn) O could obtain single rock type structure high entropy oxide at higher temperature (1250 ℃), and the preparation was carried outThe method has the defects of multiple preparation steps, complex and uncontrollable process and the like.

The combination of a one-step hydrothermal method and an annealing treatment technology is a simple means for material synthesis and modification, and has the advantages of short reaction period, low cost, no pollution, rapidness, high efficiency and the like. At present, relevant reports of preparing the high-entropy oxide material by combining a one-step hydrothermal method with an annealing treatment technology are not retrieved yet.

Disclosure of Invention

The invention aims to provide a hydrothermal method for preparing a spinel type high-entropy oxide material (MCoFeCrMn) with infrared radiation and light absorption characteristics₃O₄The method of (1).

The invention relates to a method for synthesizing spinel type high-entropy oxide material (MCoFeCrMn) by a hydrothermal method₃O₄Respectively dissolving nickel nitrate or/and copper nitrate, cobalt nitrate, ferric nitrate, chromium nitrate and manganese nitrate in ultra-pure water in equimolar proportion, and fully mixing to obtain a mixed solution of metal salts; adding a precipitant into the mixed solution, stirring uniformly, transferring to a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction, cooling to room temperature after the reaction is finished, filtering the reaction solution under reduced pressure, washing with ultrapure water, filtering, separating, precipitating, drying, and crystallizing the obtained solid powder to obtain the high-entropy oxide (MCoFeCrMn)₃O₄Wherein M = Ni or/and Cu.

Among the high-entropy oxide materials, the high-entropy oxide material prepared from four metal nitrates of Co, Fe, Cr and Mn has a spinel crystal structure and good infrared emission performance. Researches show that the addition of Ni and Cu has no significant influence on the crystal form of the material, but can significantly improve the emissivity of the material in an infrared light area.

In the mixed solution, the concentrations of nickel nitrate or/and copper nitrate, cobalt nitrate, ferric nitrate, chromium nitrate and manganese nitrate are 0.1-0.6 mol/L, so that the normal operation of the hydrothermal reaction is ensured.

The precipitator is one or two of sodium hydroxide, ammonia water, sodium carbonate and sodium bicarbonate; the molar ratio of the precipitant to the total metal nitrate is 2: 1-6: 1. The effect of adding the precipitant is to form a stable spinel structure during the formation of the solid solution. The type and the adding amount of the precipitant have certain influence on the microscopic morphology, the crystal form and the phase purity of the product, a few of precipitants are added to cause that some peaks in an X-ray diffraction pattern cannot be presented, and excessive precipitants are added to cause that phases are impure and excessive impurity peaks appear in the X-ray diffraction pattern.

The temperature of the hydrothermal reaction is 120-180 ℃, and the reaction time is 1-7 h. The temperature and time of the hydrothermal reaction have certain influence on the crystal form and the phase structure of the product, and when the temperature and the time of the hydrothermal reaction are too low and too short, a stable spinel structure cannot be formed; when the temperature of the hydrothermal reaction is too high and the time is too long, the energy consumption is high, the reaction period is prolonged, and the efficiency is obviously reduced.

The temperature of the crystallization treatment is 300-900 ℃, the temperature rising rate is 3-10 DEG/min, the heat preservation time is 2-7 h, and the temperature reduction rate is natural cooling along with the furnace. The crystallization treatment temperature, the heating rate and the heat preservation time also have great influence on the micro-morphology and the crystal form of the product. Researches show that the crystallization treatment temperature can improve the emissivity of the infrared light region in the material to a certain extent.

The high-entropy oxide material (MCoFeCrMn) prepared by the present invention was measured by X-ray diffractometer (XRD) manufactured by Pasnake, Holland₃O₄(M = Ni or/and Cu) structure analysis (FIG. 1, FIG. 5) showed that the prepared high entropy oxide (MCoFeCrMn)₃O₄Has a spinel face-centered cubic structure (Fd-3 m space group). High entropy oxide (MCoFeCrMn)₃O₄The (M = Ni or/and Cu) face-centered cubic spinel structure is not only an important commercial metal high-entropy system, but also has higher ductility and fracture toughness, the price of the required raw materials is relatively low, and therefore the structure is attractive, and the structure has a remarkable improvement effect on infrared emission performance.

High entropy oxide (MCoFeCrMn) prepared by using Scanning Electron Microscope (SEM) to attach energy to the main body₃O₄Was analyzed for morphology and microstructure (FIG. 2), indicating that the prepared high entropy oxide (MCoFeCrMn)₃O₄The powder has porous and fluffy bubblesThe fine particles in the form of a foam are uniformly distributed around the large particles.

Quantitative analysis of high entropy oxides (MCoFeCrMn) by X-ray energy Spectroscopy (EDS)₃O₄The content of the element (as shown in fig. 4) can determine that the proportion of the contained metal element is close to equimolar.

The (MCoFeCrMn) prepared by the invention is measured by a direct-reading infrared emissivity tester₃O₄The infrared emissivity of the high-entropy oxide shows that (MCoFeCrMn)₃O₄The normal emissivity of the high-entropy oxide in a wave band of 3-12 mu m is more than or equal to 0.95. I.e. having a high ir emissivity.

The high entropy oxide was tested using a Lambda 950 ultraviolet visible near infrared spectrophotometer and the results showed (MCoFeCrMn)₃O₄The absorptivity of the high-entropy oxide in a wave band of 0.3-2.5 mu m is more than or equal to 0.88, namely the high light absorptivity is achieved. The main reason is that the addition of Cu and Ni can widen the light absorption range and contribute to the improvement of the light absorption rate.

The invention relates to a hydrothermal synthesis method (MCoFeCrMn)₃O₄The high entropy oxide has the following advantages:

1. the metal salt is used as a raw material, so that the raw material source is wide and the cost is low;

2. by adopting a hydrothermal method, the raw materials are mixed under a liquid phase condition, so that the metal elements can be fully and uniformly mixed, and the product can realize the designed stoichiometric ratio; the reaction condition is mild, the energy is saved, the efficiency is high, the cost is low, and the reaction process is green and environment-friendly;

3. the solar energy absorption film has high light absorption rate, is used in the field of solar energy absorption, and can directly convert solar energy into electric energy, light energy, heat energy and the like;

4. the high-emissivity carbon has high infrared emissivity, is used in the field of infrared heating, can relieve the current energy crisis, can save energy and improve efficiency, and promotes carbon peak reaching and carbon neutralization in the industrial field.

Drawings

FIG. 1 is (NiCoFeCrMn) prepared in example 1₃O₄XRD pattern of high entropy oxide powder.

FIG. 2 is (NiCoFeCrMn) prepared in example 1₃O₄SEM image of high entropy oxide powder.

FIG. 3 is (NiCoFeCrMn) prepared in example 1₃O₄Elemental distribution of high entropy oxide powders.

FIG. 4 is (NiCoFeCrMn) prepared in example 1₃O₄EDS analysis of high entropy oxide powders.

FIG. 5 is a photograph of a film prepared in example 5 (NiCuCoFeCrMn)₃O₄XRD pattern of high entropy oxide powder.

Detailed Description

The preparation of the spinel-type high-entropy oxide material synthesized by the method and the infrared radiation performance of the spinel-type high-entropy oxide material are further described by specific implementation.

Example 1, (NiCoFeCrMn)₃O₄Preparation and Properties of high entropy oxides

Weighing 1.7563g (0.006 mol) of nickel nitrate, 1.7457g (0.006 mol) of cobalt nitrate, 2.4243 g (0.006 mol) of ferric nitrate, 2.4539 g (0.006 mol) of chromium nitrate and 2.1653 g (0.006 mol) of manganese nitrate, respectively dissolving in 12 mL of ultrapure water, uniformly stirring, and continuously stirring the five metal salt solutions until the five metal salt solutions are completely and uniformly mixed to obtain a mixed solution of metal nitrate; then 2.5438g (0.024 mol) of sodium carbonate is weighed and added into the mixed solution to be stirred evenly; then transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel reaction kettle, placing the reaction kettle in a 150 ℃ blast oven for heat preservation treatment for 4 hours, and then cooling to room temperature; filtering the reaction solution under reduced pressure, washing with ultrapure water for 5 times, filtering, separating, precipitating, and drying to obtain solid powder; finally, the obtained solid powder is placed in a 500 ℃ heat preservation furnace for heat preservation for 5 hours for crystallization treatment (in the crystallization treatment process, the heating rate is 5 DEG/min, the cooling rate is natural cooling along with the furnace), and (NiCoFeCrMn) is obtained₃O₄A high entropy oxide.

Prepared by this example (NiCoFeCrMn)₃O₄XRD of the high entropy oxide is shown in figure 1. As can be seen from FIG. 1, the prepared high entropy oxide (NiCoFeCrMn)₃O₄Is of a spinel structure; the SEM is shown in FIG. 2. As can be seen from FIG. 2, the high entropy oxide (N) producediCoFeCrMn)₃O₄The powder is porous and has fine, fluffy, foamy particles evenly distributed around the large particles. The element distribution characterization analysis is shown in fig. 3, and it can be known that the elements of Ni, Co, Fe, Cr, Mn and O are uniformly distributed in the whole area, which proves the uniformity of the chemical and microstructure. The X-ray energy spectrum (EDS) shown in fig. 4 can confirm that the ratio of the contained metal elements is close to equimolar. Infrared radiation performance: the normal emissivity of the wave band of 3-12 mu m is more than or equal to 0.95. Light absorption properties: the absorption rate in the wave band of 0.3-2.5 μm is 0.89.

Example 2, (NiCoFeCrMn)₃O₄Preparation and Properties of high entropy oxides

Weighing 1.7563g (0.006 mol) of nickel nitrate, 1.7457g (0.006 mol) of cobalt nitrate, 2.4243 g (0.006 mol) of ferric nitrate, 2.4539 g (0.006 mol) of chromium nitrate and 2.1653 g (0.006 mol) of manganese nitrate, respectively dissolving in 60 mL of ultrapure water, uniformly stirring, and continuously stirring the five metal salt solutions until the five metal salt solutions are completely and uniformly mixed to obtain a mixed solution of metal nitrate; 1.2719 g of sodium carbonate (0.012 mol) is weighed and added into the mixed solution to be evenly stirred; then transferring the mixed solution to a polytetrafluoroethylene-lined stainless steel reaction kettle, placing the reaction kettle in a blast oven at 120 ℃, and carrying out heat preservation treatment for 1 h; cooling to room temperature, filtering the reaction solution under reduced pressure, washing with ultrapure water for 3 times, filtering, separating, precipitating, and drying to obtain solid powder; finally, the obtained solid powder is placed in a 300 ℃ heat preservation furnace for heat preservation for 2h for crystallization treatment (the temperature rising rate in the crystallization treatment process is 3 DEG/min, the temperature reduction rate is natural cooling along with the furnace), and the (NiCoFeCrMn) is obtained₃O₄A high entropy oxide.

Prepared by this example (NiCoFeCrMn)₃O₄Infrared radiation performance of high entropy oxides: the normal emissivity at the wave band of 3-12 mu m is more than or equal to 0.93. Light absorption properties: the absorptivity of the composite material in a wave band of 0.3-2.5 mu m is 0.90.

Example 3, (NiCoFeCrMn)₃O₄Preparation and Properties of high entropy oxides

1.7563g (0.006 mol) of nickel nitrate, 1.7457g (0.006 mol) of cobalt nitrate, 2.4243 g (0.006 mol) of iron nitrate were weighed2.4539 g (0.006 mol) of chromium nitrate and 2.1653 g (0.006 mol) of manganese nitrate are respectively dissolved in 10 mL of ultrapure water and uniformly stirred, and five metal salt solutions are mixed and continuously stirred until the five metal salt solutions are completely and uniformly mixed to obtain a mixed solution of metal nitrate; 3.8156 g (0.036 mol) of sodium carbonate is weighed and added into the mixed solution to be uniformly stirred; then transferring the mixed solution into a polytetrafluoroethylene-lined stainless steel reaction kettle, placing the reaction kettle in a blowing oven at 180 ℃ for heat preservation treatment for 7 hours, cooling to room temperature, filtering the reaction solution under reduced pressure, washing the reaction solution with ultrapure water for 7 times, carrying out suction filtration, separation and precipitation, and drying to obtain solid powder; finally, the obtained solid powder is placed in a heat preservation furnace at 900 ℃ for heat preservation for 7 h for crystallization treatment (the temperature rising rate in the crystallization treatment process is 10 DEG/min, the temperature reduction rate is natural cooling along with the furnace), and (NiCoFeCrMn) is obtained₃O₄A high entropy oxide.

Prepared by this example (NiCoFeCrMn)₃O₄Infrared radiation performance of high entropy oxides: the normal emissivity at the wave band of 3-12 mu m is more than or equal to 0.94. Light absorption properties: the absorptivity of the composite material in a wave band of 0.3-2.5 mu m is 0.88.

Example 4, (CuCoFeCrMn)₃O₄Preparation and performance of high-entropy oxide

Weighing 1.4577 g (0.006 mol) of copper nitrate, 1.7434 g (0.006 mol) of cobalt nitrate, 2.4232 g (0.006 mol) of ferric nitrate, 2.4567 g (0.006 mol) of chromium nitrate and 2.1657 g (0.006 mol) of manganese nitrate, respectively dissolving in 12 mL of ultrapure water, uniformly stirring, and continuously stirring the five metal salt solutions until the five metal salt solutions are completely and uniformly mixed to obtain a mixed solution of metal nitrate; then 2.5438g (0.024 mol) of sodium carbonate is weighed and added into the mixed solution to be stirred evenly; then transferring the mixed solution to a polytetrafluoroethylene-lined stainless steel reaction kettle, placing the reaction kettle in a blowing oven at 150 ℃, preserving heat for 4 hours, cooling to room temperature, filtering the reaction solution under reduced pressure, washing the reaction solution with ultrapure water for 5 times, carrying out suction filtration, separation and precipitation, and drying to obtain solid powder; finally, the obtained solid powder is placed in a 500 ℃ heat preservation furnace for heat preservation for 5 hours for crystallization treatment (the temperature rise rate in the crystallization treatment process is 5 DEG/min, and the temperature reduction rate is natural cooling along with the furnace) to obtain the product (CuCoFeCrMn)₃O₄A high entropy oxide.

Prepared by this example (NiCoFeCrMn)₃O₄Infrared radiation performance of high entropy oxides: the normal emissivity at the wave band of 3-12 mu m is more than or equal to 0.96. Light absorption properties: the absorption rate in the wave band of 0.3-2.5 μm is 0.89.

Example 5, (NiCuCoFeCrMn)₃O₄Preparation and performance of high-entropy oxide

(1) Weighing 1.7526 g (0.006 mol) of nickel nitrate, 1.4598 g (0.006 mol) of copper nitrate, 1.7498 g (0.006 mol) of cobalt nitrate, 2.4225 g (0.006 mol) of ferric nitrate, 2.4572 g (0.006 mol) of chromium nitrate and 2.1532 g (0.006 mol) of manganese nitrate, respectively dissolving in 12 mL of ultrapure water, uniformly stirring, and continuously stirring five metal salt solutions until the five metal salt solutions are completely and uniformly mixed to obtain a mixed solution of metal nitrate; then 2.5438g (0.024 mol) of sodium carbonate is weighed and added into the mixed solution to be stirred evenly; then transferring the mixed solution to a polytetrafluoroethylene-lined stainless steel reaction kettle, placing the reaction kettle in a blowing oven at 150 ℃, preserving heat for 4 hours, cooling to room temperature, filtering the reaction solution under reduced pressure, washing the reaction solution with ultrapure water for 5 times, carrying out suction filtration, separation and precipitation, and drying to obtain solid powder; finally, the obtained solid powder is placed in a 500 ℃ heat preservation furnace for heat preservation for 5 hours for crystallization treatment (the temperature rise rate in the crystallization treatment process is 5 DEG/min, and the temperature reduction rate is natural cooling along with the furnace) to obtain (NiCuCoFeCrMn)₃O₄A high entropy oxide.

Prepared by this example (NiCuCoFeCrMn)₃O₄XRD of the high entropy oxide is shown in fig. 5. As can be seen from FIG. 5, the prepared high entropy oxide (NiCuCoFeCrMn)₃O₄Is of spinel structure. Infrared radiation performance: the normal emissivity at the wave band of 3-12 mu m is more than or equal to 0.96. Light absorption properties: the absorptivity of the composite material in a wave band of 0.3-2.5 mu m is 0.88.