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CN-121651428-B - Bismuth hexanitrite octahydrate crystal adsorbent and preparation method and application thereof

CN121651428BCN 121651428 BCN121651428 BCN 121651428BCN-121651428-B

Abstract

The invention relates to the technical field of inorganic functional materials, in particular to a bismuth hexanitrite octahydrate crystal adsorbent, a preparation method and application thereof, wherein the bismuth hexanitrite octahydrate crystal adsorbent has a chemical formula of Bi 2 (NO 2 ) 6 ·8H 2 O, belongs to a triclinic system, has a space group of P ‑1 , has a three-dimensional open framework structure constructed by nitrite bridging bismuth ions and a crystal water hydrogen bond network, adopts a method of combining solvothermal synthesis of bismuth nitrate pentahydrate and 4-aminopyridine quaternary ammonium salt in a hydrobromic acid ethanol system and room temperature crystallization, has a simple preparation process, mild condition and controllable cost, and has remarkable industrial application potential in the field of deep decolorization treatment of industrial printing and dyeing wastewater.

Inventors

  • ZHAO SHUNPING
  • XU YAN
  • YUAN JINMEI
  • Fan Yule
  • GUO YU
  • WANG JIE
  • XU HENG
  • SHEN GUOPING

Assignees

  • 安庆师范大学

Dates

Publication Date
20260508
Application Date
20260120

Claims (10)

  1. 1. Bismuth hexanitrite octahydrate crystal adsorbent characterized by the chemical formula Bi 2 (NO 2 ) 6 ·8H 2 O, crystal structure belonging to triclinic system, space group P -1 , unit cell parameters a= 9.1076 (3) a, b= 9.5113 (2) a, c= 11.0313 (3) a, α= 101.438 (2) °, β= 101.214 (2) °, γ= 105.963 (2) °, unit cell volume v= 868.49 (5) a 3 ; The bismuth hexanitrite octahydrate crystal adsorbent comprises two different nine-coordination bismuth centers, nitrite bridges adjacent bismuth ions through oxygen atoms, and crystal water molecules jointly construct a three-dimensional supermolecular frame through coordination bonds and hydrogen bonds.
  2. 2. The method for preparing bismuth hexanitrite octahydrate crystal adsorbent according to claim 1, comprising the steps of: respectively dissolving bismuth nitrate pentahydrate and 4-aminopyridine quaternary ammonium salt in absolute ethyl alcohol to form bismuth nitrate pentahydrate uniform solution and 4-aminopyridine quaternary ammonium salt ethanol solution; adding hydrobromic acid aqueous solution into bismuth nitrate pentahydrate uniform solution, and carrying out a first reflux reaction to form a reaction system; Adding a 4-aminopyridine quaternary ammonium salt ethanol solution into the reaction system, adding a hydrobromic acid aqueous solution to maintain the acidic environment of the reaction system, and carrying out a second reflux reaction to obtain a filtrate; And standing the filtrate for crystallization to obtain the bismuth hexanitrite octahydrate crystal adsorbent.
  3. 3. The method for preparing bismuth hexanitrite octahydrate crystal adsorbent according to claim 2, wherein the molar ratio of bismuth nitrate pentahydrate to 4-aminopyridine quaternary ammonium salt is 1:1-1.2.
  4. 4. The preparation method of the bismuth hexanitrite octahydrate crystal adsorbent according to claim 2, wherein the mass concentration of the hydrobromic acid aqueous solution is 33% -48%, and the molar ratio of bismuth nitrate pentahydrate to hydrobromic acid is 1:3.0-3.2.
  5. 5. The preparation method of the bismuth hexanitrite octahydrate crystal adsorbent is characterized in that standing crystallization adopts a staged temperature control strategy, concentrated filtrate is firstly kept standing for 2-3 weeks at 15-20 ℃ to induce nucleation, and then is transferred to a 25 ℃ environment to continue standing for 6-8 weeks to promote crystal growth.
  6. 6. The method for preparing the bismuth hexanitrite octahydrate crystal adsorbent according to claim 2, wherein the temperature is 40-50 ℃ and the time is 16-24 hours in the first reflux reaction, and the temperature is 60-70 ℃ and the time is 16-24 hours in the second reflux reaction.
  7. 7. The method for preparing bismuth hexanitrite octahydrate crystal adsorbent according to claim 2, wherein the post-treatment of the second reflux reaction is to concentrate the reaction liquid to 1/5~2/5 of the original volume by rotary evaporation in a water bath at 45-65 ℃ and a vacuum degree of not less than 0.09 MPa, and filtering.
  8. 8. Use of the bismuth hexanitrite octahydrate crystal adsorbent according to claim 1 in dye wastewater treatment.
  9. 9. The use of bismuth hexanitrite octahydrate crystal adsorbent in dye wastewater treatment according to claim 8, wherein the bismuth hexanitrite octahydrate crystal adsorbent is used for adsorption removal of cationic dye methylene blue.
  10. 10. The application of the bismuth hexanitrite octahydrate crystal adsorbent in dye wastewater treatment according to claim 9, wherein the adding amount of the adsorbent in the dye wastewater with the initial concentration of methylene blue of 200 mg/L-300 mg/L is 0.5 g/L-1.0 g/L, the adsorption equilibrium time is 2 h-4 h, and the equilibrium adsorption capacity is not lower than 600mg/g.

Description

Bismuth hexanitrite octahydrate crystal adsorbent and preparation method and application thereof Technical Field The invention relates to the technical field of inorganic functional materials, in particular to a bismuth hexanitrite octahydrate crystal adsorbent and a preparation method and application thereof. Background Dye wastewater produced in the industries of printing and dyeing, textile and the like has the characteristics of complex components, high chromaticity, high toxicity, difficult biodegradation and the like, and is one of the difficulties in industrial wastewater treatment. The adsorption method is one of the mainstream technologies for advanced treatment of dye wastewater because of the advantages of simple operation, high treatment efficiency, no secondary pollution and the like. Among them, activated carbon is the most commonly used commercial adsorbent, but has the defects of limited adsorption capacity, common methylene blue of less than 200 mg/g, difficult regeneration, higher cost, easy saturation and the like, and limits the large-scale application of the activated carbon. However, the existing researches focus on a few forms of bismuth oxide, bismuth oxyhalide and the like, and the application research of the bismuth oxyhalide as an adsorbent is relatively limited, and the performance is to be improved. Bismuth nitrate pentahydrate (Bi (NO 3)3·5H2 O) is widely used as a common bismuth salt precursor in material synthesis, but the performance of bismuth nitrate pentahydrate as an adsorption material is freshly researched and reported, and in the prior art, although various adsorption materials aiming at dye wastewater exist, such as modified clay, high molecular polymers, metal Organic Frameworks (MOFs) and the like, the problems of complex synthesis process, high cost, poor stability or unsatisfactory adsorption effect exist. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide the bismuth hexanitrite octahydrate crystal adsorbent, and the preparation method and the application thereof, wherein the adsorbent forms rich active sites and pore canal systems through a unique coordination polymer structure and a hydrogen bond network, and the method adopts solvothermal synthesis combined with a room temperature crystallization method, so that the raw materials are easy to obtain, the reaction condition is mild, complex equipment is not required, and the bismuth hexanitrite crystal adsorbent is suitable for large-scale production. In order to solve the technical problems, the invention adopts the following technical scheme: Bismuth hexanitrite octahydrate crystal adsorbent, the chemical formula is Bi 2(NO2)6·8H2 O, the crystal structure belongs to a triclinic system, the space group P -1, the unit cell parameters are a= 9.1076 (3) A, b= 9.5113 (2) A, c= 11.0313 (3) A, alpha= 101.438 (2) °, beta= 101.214 (2) °, gamma= 105.963 (2) °, and the unit cell volume V= 868.49 (5) A3. The bismuth hexanitrite octahydrate crystal adsorbent comprises two different nine-coordination bismuth centers, nitrite bridges adjacent bismuth ions through oxygen atoms, and crystal water molecules jointly construct a three-dimensional supermolecular frame through coordination bonds and hydrogen bonds. In a preferred embodiment of the present invention, the preparation method of the bismuth hexanitrite octahydrate crystal adsorbent comprises the following steps: Bismuth nitrate pentahydrate and 4-aminopyridine quaternary ammonium salt are respectively dissolved in absolute ethyl alcohol to form bismuth nitrate pentahydrate uniform solution and 4-aminopyridine quaternary ammonium salt ethanol solution. Adding hydrobromic acid aqueous solution into the bismuth nitrate pentahydrate uniform solution, and carrying out a first reflux reaction to form a reaction system. Adding the 4-aminopyridine quaternary ammonium salt ethanol solution into the reaction system, adding hydrobromic acid aqueous solution to maintain the acidic environment of the reaction system, and carrying out a second reflux reaction to obtain filtrate. And standing the filtrate for crystallization to obtain the bismuth hexanitrite octahydrate crystal adsorbent. In a preferred embodiment of the invention, the molar ratio of bismuth nitrate pentahydrate to the 4-aminopyridine quaternary ammonium salt is 1:1-1.2. In the preferred embodiment of the invention, the mass concentration of the hydrobromic acid aqueous solution is 33% -48%, and the molar ratio of the bismuth nitrate pentahydrate to the hydrobromic acid is 1:3.0-3.2. In the preferred embodiment of the invention, a staged temperature control strategy is adopted for standing crystallization, namely concentrated filtrate is firstly subjected to standing at 15-20 ℃ for 2-3 weeks to induce nucleation, then is transferred to a 25 ℃ environment to continue standing for 6-8 weeks to promote crystal growth, and the method can obtain a product with larger average par