Composite material used for catalyzing and degrading nitrogen oxide and preparation method and application thereof

• US 20170173571A1
• Filed: 12/17/2016
• Published: 06/22/2017
• Est. Priority Date: 12/17/2015
• Status: Active Grant

• Current Assignee: Soochow University (Jiangsu Education Department)
• Original Assignee: Soochow University (Jiangsu Education Department)
• Inventors: LU, Jianmei, CHEN, Dongyun
• Granted Patent: US 10,441,945 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2255/70 Non-metallic catalysts, additives or dopants
• CPC Class Codes: B01D 2255/702 Carbon
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 2259/802 Visible light
• CPC Class Codes: B01D 53/8628 Processes characterised by a specific catalyst
• CPC Class Codes: B01J 19/127 Sunlight; Visible light
• CPC Class Codes: B01J 21/18 Carbon
• CPC Class Codes: B01J 2231/005 General concepts, e.g. reviews, relating to methods of using catalyst systems, the concept being defined by a common method or theory, e.g. microwave heating or multiple stereoselectivity
• CPC Class Codes: B01J 2531/002 Materials
• CPC Class Codes: B01J 2531/008 Methods or theories
• CPC Class Codes: B01J 27/24 Nitrogen compounds
• CPC Class Codes: B01J 31/069 Hybrid organic-inorganic polymers, e.g. silica derivatized with organic groups nitrogen containing groups on mineral substrates B01J31/0254; organometallic polymers B01J31/123; coordination complexes immobilised on an inorganic support B01J31/1616; coordination polymers, e.g. metal-organic frameworks B01J31/1691
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/51 Spheres
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: B01J 37/0072 Preparation of particles, e.g. dispersion of droplets in an oil bath
• CPC Class Codes: B01J 37/0221 of particles
• CPC Class Codes: B01J 37/04 : Mixing B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: B01J 37/084 : Decomposition of carbon-containing compounds into carbon
• CPC Class Codes: C01B 21/0605 : Binary compounds of nitrogen with carbon

Abstract

The invention discloses a composite material used for catalyzing and degrading nitrogen oxide and its preparation method and application thereof. The invention of the hollow g-C₃N₄ nanospheres/reduced graphene oxide composite-polymer carbonized nanofiber material is prepared as follow: 1) the preparation of silica nanospheres; 2) the preparation of hollow g-C₃N₄ nanospheres; 3) the preparation of graphene oxide; 4) the preparation of surface modified hollow g-C₃N₄ nanoparticles preparation; 5) the preparation of composites; 6) the preparation of composite-polymer carbon nanofiber material. The raw materials used in the process is low cost and easy to get; the operation of the invention is simple and convenient without the use of expensive equipment in the whole process; the composite has high adsorption efficiency of ppb level nitrogen oxide with good repeatability.

Claims

1. A preparation method of a hollow graphite phase carbon nitride nanosphere/reduction-oxidation graphene composite and polymer carbide nano fiber material, comprises the following steps:

(1) preparation of silica nanospheres;

in accordance with a mass ratio of concentrated ammonia;

ethanol;

water;

ethyl silicate =1;

15˜

20;

1˜

5;

1˜

2, add ethyl silicate into a mixture of concentrated ammonia, ethanol and water, after mixing, keep standing for 1˜

2 hours, then in accordance with a mass ratio of ethyl silicate;

a mixture of ethyl silicate and octadecyltrimethoxysilane=1;

1-2, add the mixture of ethyl silicate and octadecyltrimethoxysilane, mixing evenly and keep standing for 3˜

5 hours, a resulted mixture is centrifugated, dried and calcined for 6˜

8 hours at 550˜

570°

C., and then washed with 1M hydrochloric acid and dried, to obtain the silica nanospheres,

(2) preparation of hollow graphite phase carbon nitride nanospheres;

under vacuum condition, use the silica nanospheres in the step (1) as a template and mix with cyanamide in accordance with the mass ratio of 1;

3˜

7 and stir for 3˜

5 hours, ultrasonic treat for 2˜

3 hours, and then react at 60˜

70°

C. for 10˜

12 hours and obtain a powder by centrifugation, the obtained powder is heated to 550˜

570 °

C. under inert gas atmosphere and calcined for 4˜

5 hours, then use 4M ammonium acid fluoride to etch the silica nanospheres template in the powder, after centrifuging, washing and drying, obtain the hollow graphite phase carbon nitride nanospheres,

(3) preparation of graphene oxide;

in an ice water bath and stirring conditions, add graphite to concentrated sulfuric acid with the proportion of graphite;

concentrated sulfuric acid=1 g;

20-25 mL, after mixing evenly, add potassium hypermanganate to the mixture of graphite and concentrated sulfuric acid with mass ratio of graphite;

potassium hypermanganate=1;

5˜

8, react at 35˜

40°

C. for 12 h, pour the mixture of graphite, concentrated sulfuric acid, and potassium hypermanganate into ice water containing hydrogen peroxide, after centrifugation, washing and drying, obtain the graphene oxide,

(4) preparation of surface modified hollow graphite phase carbon nitride nanospheres;

in an inert gas atmosphere, add 3-aminopropyltriethoxysilane to a suspension with the hollow graphite phase carbon nitride nanospheres dispersed in methylbenzene in accordance with the hollow graphite phase carbon nitride nanospheres;

3-aminopropyltriethoxysilane=1 g ;

3˜

5mL, after refluxing for 20˜

24 hours, by centrifugation, washing and drying, obtain the surface modified hollow graphite phase carbon nitride nanospheres,

(5) preparation of hollow graphite phase carbon nitride nanospheres/reduction-oxidation graphene composite;

in accordance with the mass ratio of the surface modified hollow graphite phase carbon nitride nanospheres;

graphene oxide=1;

0.1˜

0.3, add graphene oxide aqueous solution to the surface modified hollow graphite phase carbon nitride nanospheres in step (4) dispersed in water whose pH is 10, stir the mixture of the surface modified hollow graphite phase carbon nitride nanospheres and the graphene oxide at room temperature for 1˜

2 hours, then put hydrazine hydrate into the above mixture with mass ratio of graphene oxide;

hydrazine hydrate=1;

1;

1˜

2, react for 1˜

2 hours at 95°

C., by centrifugation, washing and drying, obtain the hollow graphite phase carbon nitride nanospheres/reduction-oxidation graphene composite,

(6) preparation of composite-carbonized polymer nanofiber material;

add the composite obtained in step (5) to DMF solution of a polymer in accordance with mass ratio of composite;

polymer=1;

15˜

20, stir the mixture of the composite and polymer at room temperature for 5˜

8 hours, prepare a nanofiber through electrostatic spinning, the nanofiber is heated to 500˜

520°

C. under inert gas atmosphere and calcined for 4˜

5 hours, to obtain the composite-carbonized polymer nanofiber material.

2. The preparation method according to claim 1, wherein:

the mass ratio of said concentrated ammonia, ethanol, water, and ethyl silicate in step (1) is 1;

18.7;

3.2;

1.8;

the mass percentage of concentrated ammonia in step (1) is 22%˜

25%;

the mass ratio of the ethyl silicate and the mixed liquid of ethyl silicate and octadecyltrimethoxysilane in step (1) is 1;

1.5; and

the mass ratio of the ethyl silicate and octadecyltrimethoxysilane in the mixed liquid of the ethyl silicate and octadecyltrimethoxysilane in step (1) is 1;

0.45.

3. The preparation method according to claim 1, wherein:

the mass ratio of said silica nanospheres and cyanamide in step (2) is 1;

5.

4. The preparation method according to claim 1, wherein:

the ratio of graphite and concentrated sulfuric acid in step (3) is 1 g;

23 mL;

the mass ratio of graphite and Potassium Permanganate in step (3) is 1;

6; and

Potassium Permanganate is divided into two batches with the same mass in step (3).

5. The preparation method according to claim 1, wherein:

the ratio of said hollow graphite phase carbon nitride nanosphere and 3-aminopropyltriethoxysilane in step (4) is 1 g;

3 mL; and

the concentration of the hollow graphite phase carbon nitride nanosphere in said suspension in step (4) is 1 mg/mL.

6. The preparation method according to claim 1, wherein:

the mass ratio of said surface modified hollow graphite phase carbon nitride nanospheres and the graphene oxide in step (5) is 1;

0.1;

the concentration of surface modified hollow graphite phase carbon nitride nanospheres in said suspension in step (5) is 1 mg/mL;

the concentration of graphene oxide in aqueous solution in step (5) is 0.1 mg/mL; and

the mass ratio of said graphene oxide and the hydrazine hydrate in step (5) is 1;

1.

7. The preparation method according to claim 1, wherein:

the mass ratio of the composite and the polymer in step (6) is 1;

20;

said polymer in step (6) is selected from any one of PAN, polyvinyl alcohol and polyvinylpyrrolidone;

the mass percentage of the polymer in dimethylformamide in step (6) is 10%; and

the conditions of said electrostatic spinning in step (6) are as follows;

negative voltage −

9 kV, positive voltage 18 kV, speed 0.2 mm/min.

8. A hollow graphite phase carbon nitride nanosphere/reduction-oxidation graphene composite and polymer carbide nano fiber material prepared by the preparation method of claim 1.

9. A method of catalyzing and degrading nitrogen oxide comprising contacting the nitrogen oxide with the hollow graphite phase carbon nitride nanosphere/reduction-oxidation graphene composite and polymer carbide nano fiber material described in claim 8.

10. The method according to claim 9, wherein, said nitrogen oxide is nitric oxide.