a g-c 3 n 4 --cnts heterojunction photocatalyst and preparation method thereof

Abstract

The invention discloses a g-C 3 N 4 - Preparation method of CNTs heterojunction photocatalyst. The method comprises the steps of: uniformly mixing melamine and carbon nanotubes and calcining at high temperature to obtain g-C 3 N 4 / CNTs; the resulting g‑C 3 N 4 / CNTs are placed in a mixture of sulfuric acid / nitric acid for acidification and oxidation treatment to obtain surface carboxylated g‑C 3 N 4 / CNTs‑COOH; convert the resulting g‑C 3 N 4 / CNTs‑COOH reacts under the action of dehydrating agent to obtain g‑C 3 N 4 – CNTs heterojunction photocatalyst.

Description

Technical field

[0001] The invention relates to the field of photocatalytic materials, in particular to a g-C 3 N 4 -CNTs heterojunction photocatalyst and its preparation method. Background technique

[0002] As an emerging and green technology, photocatalysis based on semiconductor materials has great potential in solving energy shortages and environmental problems. Graphite phase carbon nitride (g-C 3 N 4 ) As a completely non-metal semiconductor, it has the advantages of stable chemical properties, narrow band gap, and strong compatibility. 2 After that, another star material in the field of photocatalysis. However, studies have found that in the photocatalytic reaction, g-C 3 N 4 Surface photogenerated electrons and holes are very easy to recombine, resulting in low light quantum efficiency and inhibited photocatalytic activity. Therefore, in the g-C 3 N 4 In the research and development, how to promote the separation of photogenerated electrons and holes on its surface has ...

Examples

Embodiment 1

[0027] Example 1g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0028] (1) After uniformly mixing 30g of melamine and 1g of CNTs, place it in a tube furnace and calcinate at 450°C for 4h in an air atmosphere to obtain g-C 3 N 4 / CNTs.

[0029] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:2) mixed acid solution, refluxed for 12h at 40℃, washed the reacted product with distilled water and dried to obtain g-C 3 N 4 / CNTs-COOH.

[0030] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and add 1g dicyclohexylcarbodiimide at the same time, heat and reflux for 8h at 50℃, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

Embodiment 2

[0031] Example 2g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0032] (1) After uniformly mixing 30g of melamine and 1.5g of CNTs, place it in a tube furnace and calcinate at 500°C for 4h in an air atmosphere to obtain g-C 3 N 4 / CNTs.

[0033] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:2) mixed acid solution, refluxed at 45℃ for 16h, the product after the reaction was washed with distilled water and dried to obtain g-C 3 N 4 / CNTs-COOH.

[0034] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and at the same time add 1.5g dicyclohexylcarbodiimide, heat and reflux at 55℃ for 12h, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

Embodiment 3

[0035] Example 3g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0036] (1) After mixing 30g of melamine and 2g of CNTs uniformly, place it in a tube furnace and calcinate at 520℃ for 4h under air atmosphere to obtain g-C 3 N 4 / CNTs.

[0037] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:3) mixed acid solution, refluxed for 24h at 45℃, washed the reacted product with distilled water and dried to prepare g-C 3 N 4 / CNTs-COOH.

[0038] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and add 2g dicyclohexylcarbodiimide at the same time, heat and reflux for 12h at 60℃, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

Technical field

[0001] The invention relates to the field of photocatalytic materials, in particular to a g-C 3 N 4 -CNTs heterojunction photocatalyst and its preparation method. Background technique

[0002] As an emerging and green technology, photocatalysis based on semiconductor materials has great potential in solving energy shortages and environmental problems. Graphite phase carbon nitride (g-C 3 N 4 ) As a completely non-metal semiconductor, it has the advantages of stable chemical properties, narrow band gap, and strong compatibility. 2 After that, another star material in the field of photocatalysis. However, studies have found that in the photocatalytic reaction, g-C 3 N 4 Surface photogenerated electrons and holes are very easy to recombine, resulting in low light quantum efficiency and inhibited photocatalytic activity. Therefore, in the g-C 3 N 4 In the research and development, how to promote the separation of photogenerated electrons and holes on its surface has ...

Examples

Embodiment 1

[0027] Example 1g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0028] (1) After uniformly mixing 30g of melamine and 1g of CNTs, place it in a tube furnace and calcinate at 450°C for 4h in an air atmosphere to obtain g-C 3 N 4 / CNTs.

[0029] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:2) mixed acid solution, refluxed for 12h at 40℃, washed the reacted product with distilled water and dried to obtain g-C 3 N 4 / CNTs-COOH.

[0030] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and add 1g dicyclohexylcarbodiimide at the same time, heat and reflux for 8h at 50℃, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

Embodiment 2

[0031] Example 2g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0032] (1) After uniformly mixing 30g of melamine and 1.5g of CNTs, place it in a tube furnace and calcinate at 500°C for 4h in an air atmosphere to obtain g-C 3 N 4 / CNTs.

[0033] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:2) mixed acid solution, refluxed at 45℃ for 16h, the product after the reaction was washed with distilled water and dried to obtain g-C 3 N 4 / CNTs-COOH.

[0034] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and at the same time add 1.5g dicyclohexylcarbodiimide, heat and reflux at 55℃ for 12h, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

Embodiment 3

[0035] Example 3g-C 3 N 4 -CNTs heterojunction photocatalyst preparation:

[0036] (1) After mixing 30g of melamine and 2g of CNTs uniformly, place it in a tube furnace and calcinate at 520℃ for 4h under air atmosphere to obtain g-C 3 N 4 / CNTs.

[0037] (2) The g-C obtained in step (1) 3 N 4 / CNTs weighed 2.0g and added to 40mL sulfuric acid / nitric acid (volume ratio 1:3) mixed acid solution, refluxed for 24h at 45℃, washed the reacted product with distilled water and dried to prepare g-C 3 N 4 / CNTs-COOH.

[0038] (3) The g-C obtained in step (2) 3 N 4 / CNTs-COOH Weigh 1.5g into 150mL tetrahydrofuran solution, and add 2g dicyclohexylcarbodiimide at the same time, heat and reflux for 12h at 60℃, wash and dry the reaction product to obtain g-C 3 N 4 -CNTs heterojunction photocatalyst.

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