Method for rapidly preparing Prussian blue analogue with monoclinic crystal structure

Abstract

The present invention discloses a method for rapidly preparing a Prussian blue analogue with a monoclinic crystal structure. The Prussian blue analogue with a monoclinic crystal structure has a chemical formula of Na.sub.xM[Fe(CN).sub.6].sub.y.Math.zH.sub.2O, where M=Mn or Fe, 1.5<×<2, and 0.5<y<1. In this method, a mixture of sodium ferrocyanide and sodium chloride is adopted as a solution A, and a solution of manganese salt or iron salt in water is adopted as a solution B; the solutions A and B are continuously and rapidly mixed by a micromixer, and the precipitation reaction is conducted to obtain a nano-precursor slurry; and the nano-precursor slurry is aged at 80° C. to 160° C. for 3 min to 2 h to obtain a Prussian blue analogue with a monoclinic crystal structure that has a particle diameter of 200 nm to 2,000 nm.

Claims

1. A method for rapidly preparing a Prussian blue analogue with a monoclinic crystal structure, comprising the following steps: a) preparing a mixture of sodium ferrocyanide and sodium chloride as a raw material A; b) preparing a solution of manganous salt or ferrous salt as a raw material B; c) rapidly mixing the raw materials A and B with a micromixer, and conducting precipitation reaction to obtain a precursor slurry C; d) aging the precursor slurry C obtained in step c) at 80° C. to 160° C. under a nitrogen or argon atmosphere for 3 min to 2 h to obtain an aged slurry; and e) filtering out precipitates from the aged slurry obtained in step d), and washing and drying the precipitates to obtain the Prussian blue analogue with a monoclinic crystal structure; wherein in the raw material A, the mixture has a concentration of 0.05 mol/L to 1 mol/L of the sodium ferrocyanide, and a concentration of 0.5 mol/L to 6 mol/L of the sodium chloride, in the raw material B, the solution has a concentration of 0.05 mol/L to 3 mol/L of the manganous salt or the ferrous salt, the sodium ferrocyanide of the raw material A and the raw material B are used at a molar ratio of 1:(0.5-3), and the micromixer is selected from the group consisting of: a membrane dispersion micromixer, a microsieved micromixer, and a cocurrent microslot mixer.

2. The method according to claim 1, wherein the Prussian blue analogue with a monoclinic crystal structure has a chemical formula of Na.sub.xM[Fe(CN).sub.6].sub.y.Math.zH.sub.2O, wherein M=Mn or Fe, 1.5<x<2, and 0.5<y<1.

3. The method according to claim 1, wherein the manganous salt is one or a mixture of manganese chloride, manganese sulfate and manganese nitrate, and the ferrous salt is one or a mixture of ferrous chloride, ferrous sulfate and ferrous nitrate.

4. The method according to claim 1, wherein the obtained Prussian blue analogue with a monoclinic crystal structure has a particle diameter of 200 nm to 2,000 nm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a flowchart of a process according to the present invention;

(2) FIG. 2 is an X-ray diffraction pattern for the manganese-based Prussian blue analogue with a monoclinic crystal structure prepared in Example 1 of the present invention;

(3) FIG. 3 is an SEM image for the precursor prepared in Example 1 of the present invention;

(4) FIG. 4 is an SEM image for the manganese-based Prussian blue analogue with a monoclinic crystal structure prepared in Example 1 of the present invention; and

(5) FIG. 5 is an X-ray diffraction pattern for the iron-based Prussian blue analogue with a monoclinic crystal structure prepared in Example 2 of the present invention.

DETAILED DESCRIPTION

(6) The present invention is further described below with reference to the accompanying drawings and examples.

Example 1

(7) An aqueous solution of 0.05 mol/L sodium ferrocyanide and 0.5 mol/L sodium chloride was prepared to obtain a raw material A. A solution of 0.15 mol/L manganese chloride was prepared to obtain a raw material B. 1 L of the raw material A and 1 L of the raw material B were rapidly mixed using a membrane dispersion microreactor to obtain slurry C. The slurry C was aged at a high temperature of 120° C. for 2 h. Precipitates were filtered out from the slurry C, then washed and dried to obtain a Prussian blue analogue with a monoclinic crystal structure, where Na:Mn:Fe=1.72:1:0.91.

Example 2

(8) An aqueous solution of 1 mol/L sodium ferrocyanide and 6 mol/L sodium chloride was prepared to obtain a raw material A. A solution of 3 mol/L manganese chloride was prepared to obtain a raw material B. 1 L of the raw material A and 1 L of the raw material B were rapidly mixed using a microsieved micromixer to obtain slurry C. The slurry C was aged at a high temperature of 160° C. for 3 min. Precipitates were filtered out from the slurry C, then washed and dried to obtain a Prussian blue analogue with a monoclinic crystal structure, where Na:Mn:Fe=1.88:1:0.89.

Example 3

(9) An aqueous solution of 0.6 mol/L sodium ferrocyanide and 2 mol/L sodium chloride was prepared to obtain a raw material A. A solution of 0.2 mol/L manganese chloride was prepared to obtain a raw material B. 1 L of the raw material A and 1 L of the raw material B were rapidly mixed using a T-shaped micromixer to obtain slurry C. The slurry C was aged at a high temperature of 80° C. for 1 h. Precipitates were filtered out from the slurry C, then washed and dried to obtain a Prussian blue analogue with a monoclinic crystal structure, where Na:Mn:Fe=1.65:1:0.84.

Example 4

(10) An aqueous solution of 0.1 mol/L sodium ferrocyanide and 3 mol/L sodium chloride was prepared to obtain a raw material A. A solution of 0.1 mol/L ferrous chloride was prepared to obtain a raw material B. 1 L of the raw material A and 1 L of the raw material B were rapidly mixed using a membrane dispersion microreactor to obtain slurry C. The slurry C was aged at a high temperature of 140° C. for 2 h. Precipitates were filtered out from the slurry C, then washed and dried to obtain a Prussian blue analogue with a monoclinic crystal structure, where Na:Fe=0.96.

Example 5

(11) An aqueous solution of 0.1 mol/L sodium ferrocyanide and 6 mol/L sodium chloride was prepared to obtain a raw material A. A solution of 0.05 mol/L ferrous chloride was prepared to obtain a raw material B. 1 L of the raw material A and 1 L of the raw material B were rapidly mixed using a T-shaped micromixer to obtain slurry C. The slurry C was aged at a high temperature of 100° C. for 1 h. Precipitates were filtered out from the slurry C, then washed and dried to obtain a Prussian blue analogue with a monoclinic crystal structure, where Na:Fe=0.92.

(12) The technical solutions of the present invention are described in detail through above examples. Apparently, the present invention is not limited to the described examples. Those skilled in the art can also make various changes based on the examples of the present invention, but any change that is equivalent or similar to the present invention falls within the protection scope of the present invention.