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CN-116692802-B - Preparation method of high specific surface area nano cerium phosphate material

CN116692802BCN 116692802 BCN116692802 BCN 116692802BCN-116692802-B

Abstract

The invention discloses a preparation method of a high specific surface area nano cerium phosphate material. The modified corn starch has good water solubility, solution suspension property and stability after being dissolved in water, the suspension stability provides a space carrier for generating nano cerium phosphate, a grid structure is formed through hydrogen bonding between molecular weight chains of the modified corn starch, the size uniformity of cerium phosphate particles can be controlled, the concentration of the modified corn starch is controlled, different specific surface area values of the cerium phosphate are controlled, the modified corn starch can be removed through later high-temperature sintering and washing, and finally the high-purity cerium phosphate nano particles are obtained, have the characteristics of uniformity, high specific surface area and the like, and can be applied to electrode materials, adsorption materials, luminescent materials, high-molecular nano fillers and the like.

Inventors

  • WANG SHENGLONG
  • SONG LIJUN
  • WANG XINKUN
  • LIN FENGLONG
  • WU YINCAI

Assignees

  • 厦门稀土材料研究所

Dates

Publication Date
20260505
Application Date
20230518

Claims (6)

  1. 1. The preparation method of the nano cerium phosphate material with high specific surface area is characterized by comprising the following steps: (1) Mixing modified corn starch with deionized water, heating, stirring, dissolving, cooling to room temperature, and filtering to obtain modified corn starch solution; (2) Mixing phosphate with deionized water, stirring at room temperature for dissolution, and filtering to obtain a phosphate solution; (3) Mixing soluble cerium salt with deionized water, stirring at room temperature for dissolution, and filtering to obtain cerium salt solution; the mass ratio of the modified corn starch to the phosphate to the soluble cerium salt is 1.8-4.2:4.9-7.0:9.8-17.5; (4) Slowly dripping the phosphate solution into the modified corn starch solution while stirring at room temperature, continuously stirring for 3-5h after dripping, and regulating the pH value to 4-6 by using the phosphate solution; (5) Dropwise adding the cerium salt solution into the material obtained in the step (4) while stirring at room temperature, wherein the dropwise adding time is controlled to be 30-50 min, and continuing stirring for reaction for 5-8h after the dropwise adding is finished; (6) Carrying out a hydrothermal reaction on the material obtained in the step (5), wherein the hydrothermal reaction conditions are 115-125 ℃,3-5h, 145-155 ℃,5-7h, 195-205 ℃ and 7-9h; (7) Filtering the material obtained in the step (6), washing with deionized water and absolute ethyl alcohol, and drying to obtain product powder; (8) And sintering the product powder to obtain the high specific surface area nano cerium phosphate material.
  2. 2. The method of claim 1, wherein the modified corn starch contains not less than 99% of modified corn starch, not more than 0.3% of ash, not more than 5-8% of 1-5% aqueous solution, not more than 2% of protein, not more than 10% of amylose, and has a molecular weight of 30000-60000.
  3. 3. The method of claim 1, wherein the phosphate comprises at least one of sodium phosphate, potassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate.
  4. 4. The method of claim 1, wherein the soluble cerium salt comprises at least one of cerium chloride heptahydrate, cerium chloride anhydrous, cerium nitrate hexahydrate, and cerium nitrate anhydrous.
  5. 5. The method according to claim 1, wherein the hydrothermal reaction is carried out at 120℃for 4 hours, at 150℃for 6 hours, at 200℃for 8 hours.
  6. 6. The method of claim 1, wherein the sintering temperature is 500-700 ℃ and the sintering time is 3-5 hours.

Description

Preparation method of high specific surface area nano cerium phosphate material Technical Field The invention belongs to the technical field of rare earth material preparation, and particularly relates to a preparation method of a high specific surface area nano cerium phosphate material. Background Rare earth elements have many special physicochemical properties due to their 4f electronic properties. The rare earth cerium phosphate is a rare earth compound, so that the rare earth cerium phosphate has the performances of conductivity, fluorescence, catalysis and the like, can be used as mesoporous materials, conductive materials, luminescent materials, catalytic materials, humidity-sensitive sensors, heat insulation materials and the like, can be used as adsorption materials if being made into nano-scale, is arranged on an electrode, plays a role of oxidation reduction on a small molecular compound, detects the micro content of the small molecular compound through an electrochemical signal, and has the characteristics of high sensitivity, stable test and the like. The smaller the particle size of the rare earth cerium phosphate, the larger the specific surface area, the stronger the oxidation-reduction capability, and the more favorable the preparation of the high-sensitivity detection material. CN 101704543A discloses a preparation method of cerium phosphate nanowire, which comprises the steps of preparing mixed solution of Ce 3+ salt solution and PO 43- salt solution, adjusting the pH value of the mixed solution to 0.8-1.5, stirring the mixed solution for 0.3-1.5 h, and placing the mixed solution in a water bath at 90-95 ℃ for more than Chen Hua h under normal pressure to obtain the hexagonal cerium phosphate nanowire, wherein the optimal nano size is average diameter 26nm and average length 460nm. CN 101935026A discloses a method for hydrothermally synthesizing cerium phosphate nanospheres, which comprises the steps of controlling the molar ratio of Ce 3+ to polyphosphoric acid to be 1:1-10, mixing 0.1-0.8 mol/L cerium salt aqueous solution with 0.1-0.6 mol/L polyphosphoric acid aqueous solution, adding 0.1-5% (mass fraction) of dispersing agent, clarifying the mixed solution under the conditions of heating and strong stirring, placing the mixed solution into a reaction kettle for hydrothermal reaction, cooling the reaction product to room temperature after the reaction is finished, washing, drying and calcining for heat treatment, so as to obtain cerium phosphate nanospheres with diameters of hundreds of nanometers. The literature on synthesis, characterization and propane oxidative dehydrogenation exploration of mesoporous cerium phosphate catalysts reports that nano cerium phosphate with the specific surface of 152.5m 2/g is synthesized by a hydrothermal method by using a surfactant F172 as a template. The above methods are still complex, have high cost and are difficult to apply industrially. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a preparation method of a high specific surface area nano cerium phosphate material. The technical scheme of the invention is as follows: the preparation method of the nano cerium phosphate material with high specific surface area comprises the following steps: (1) Mixing the modified corn starch with deionized water, heating, stirring and dissolving, cooling to room temperature, and filtering to obtain a modified corn starch solution; (2) Mixing phosphate with deionized water, stirring at room temperature for dissolution, and filtering to obtain a phosphate solution; (3) Mixing soluble cerium salt with deionized water, stirring at room temperature for dissolution, and filtering to obtain cerium salt solution; (4) Slowly dripping the phosphate solution into the modified corn starch solution while stirring at room temperature, continuously stirring for 3-5h after dripping, and regulating the pH to 4-6 with the phosphate solution; (5) Dropwise adding the cerium salt solution into the material obtained in the step (4) for 50-80min while stirring at room temperature, and continuing stirring for reaction for 5-8h after the dropwise adding is finished; (6) Carrying out a hydrothermal reaction on the material obtained in the step (5), wherein the hydrothermal reaction conditions are 115-125 ℃,3-5h, 145-155 ℃,5-7h, 195-205 ℃ and 7-9h; (7) Filtering the material obtained in the step (6), washing with deionized water and absolute ethyl alcohol, and drying to obtain product powder; (8) And sintering the reaction powder to obtain the high specific surface area nano cerium phosphate material. In a preferred embodiment of the invention, the modified corn starch is pregelatinized corn starch or oxidized corn starch. The pregelatinized corn starch is known in the art as modified corn starch obtained by deep processing of raw corn starch, extrusion, heating, expansion, crushing and screening, and the oxidized corn starch is obtained