Precious metal loaded covalent organic framework composite material and preparation method therefor
The application belongs to the field of material preparation and environments, and specifically, to a precious metal loaded Covalent Organic Framework (COF) composite material and a preparation method therefor. The components of the composite material include precious metal nanoparticles and TpMA. The preparation method includes first mixing the TpMA, chloroauric acid and methanol; and then adding sodium borohydride for reaction, so as to obtain the composite material. The precious metal nanoparticle loaded COF material prepared in the application may be used as a catalyst, which is a novel heterogeneous catalyst with simple, green and efficient preparation; and the material is high in catalytic activity, fast in degradation rate and short in time, and may catalyze the reduction of high concentration pollutants.
1 . A method for preparing a precious metal loaded Covalent Organic Framework (COF) composite material catalyst, comprising the following steps:
(1) mixing TpMA, chloroauric acid (HAuCl 4 ) and methanol; and
(2) adding sodium borohydride (NaBH 4 ) in a reaction system of step (1) for reaction, so as to obtain the precious metal loaded covalent organic framework composite material catalyst,
wherein a mass ratio of the TpMA, the HAuCl 4 and the methanol in step (1) is 10:1-5:0.5-1.5;
a ratio of a mass of the HAuCl 4 to an amount in moles of the NaBH 4 is 1-5 g:0.4 mol; and a concentration of the NaBH 4 is 1.5-2.5 mol/L; and
the TpMA in step (1) is prepared by a process comprising:
A, first mixing p-toluenesulfonic acid and melamine, and performing grinding for 12-30 min;
B, then adding 1,3,5-triformyl phloroglucinol into a resulting reaction system of step A, and performing grinding for 2-4 h; and
C, finally adding 0.1-0.5 mL of water into a reaction system of step B, performing grinding, using DMF for washing for 2-3 times, and performing vacuum drying, so as to obtain the TpMA.
2 . The preparation method as claimed in claim 1 , further comprising: after mixing in step (1), stirring a resulting mixture at room temperature for more than 20 h.
3 . The preparation method as claimed in claim 1 , wherein a time for reaction in step (2) is 1-3 h; after the reaction is completed, a resulting reaction mixture is first washed with dichloromethane, then washed with methanol; and finally, vacuum drying is performed at a temperature of 60-70° C., so as to obtained the precious metal loaded COF composite material catalyst.
4 . The preparation method as claimed in claim 1 , a using amount ratio of the p-toluenesulfonic acid, the melamine and the 1,3,5-triformyl phloroglucinol is 0.5-1.5 mL:320-360 mg:370-390 mg.
5 . The preparation method as claimed in claim 1 , wherein in step C, a time for grinding is 4-6 h; and the vacuum drying is performed at a temperature of 55-65° C.