阅读说明：本技术 一种多孔氮化碳材料的制备方法及多孔氮化碳材料及其用途 (Preparation method of porous carbon nitride material, porous carbon nitride material and application thereof ) 是由 蔡可迎 周颖梅 王鹏 徐蕾 骆燕 莫满萍 何思敏 于 2019-08-16 设计创作，主要内容包括：本发明涉及一种多孔氮化碳材料的制备方法及多孔氮化碳材料及其用途。采用热聚合方法,该方法是以氰尿酸和小分子含氮化合物为原料,首先称取计量的氰尿酸和小分子含氮化合物,研磨混合均匀后,放入带盖坩埚中,并将坩埚置于马弗炉中进行焙烧,马弗炉以3～10℃/min的速率升温540～560℃,保温3～5h,自然冷却后得到多孔氮化碳材料；氰尿酸和小分子含氮化合物之间的质量比为1：(1～6)。该方法可简化制备过程、降低生产成本和对环境的污染、提高产品收率；制备的多孔氮化碳材料的比较面积大,能有效催化光降解罗丹明B,具有较高的催化活性和较好的重复性,在污水处理方面具有潜在的利用价值。(The invention relates to a preparation method of a porous carbon nitride material, the porous carbon nitride material and application thereof. The method comprises the steps of taking cyanuric acid and a small-molecule nitrogen-containing compound as raw materials, firstly weighing metered cyanuric acid and the small-molecule nitrogen-containing compound, grinding and mixing uniformly, putting the mixture into a crucible with a cover, putting the crucible into a muffle furnace for roasting, heating the muffle furnace to 540-560 ℃ at the speed of 3-10 ℃/min, preserving heat for 3-5 h, and naturally cooling to obtain the porous carbon nitride material; the mass ratio of the cyanuric acid to the small-molecule nitrogen-containing compound is 1: (1-6). The method can simplify the preparation process, reduce the production cost and the pollution to the environment, and improve the product yield; the prepared porous carbon nitride material has large comparative area, can effectively catalyze and photodegrade rhodamine B, has high catalytic activity and good repeatability, and has potential utilization value in the aspect of sewage treatment.)

1. A preparation method of a porous carbon nitride material is characterized by comprising the following preparation steps: grinding the metered cyanuric acid and the small molecular nitrogen-containing compound in a mortar, transferring the obtained solid mixture into a crucible with a cover, placing the crucible in a muffle furnace for roasting, heating the muffle furnace to 540-560 ℃ at the speed of 3-10 ℃/min, preserving the temperature for 3-5 h, and naturally cooling to obtain the porous carbon nitride material; the mass ratio of the cyanuric acid to the small molecular nitrogen-containing compound is 1: (1-6).

2. The method for preparing the porous carbon nitride material as claimed in claim 1, wherein the small molecular nitrogen-containing compound is one or more of urea, thiourea, dicyandiamide and cyanamide.

3. The method for preparing a porous carbon nitride material according to claim 1 or 2, wherein the mass ratio of the cyanuric acid to the small molecular nitrogen-containing compound is 1: 3.

4. The method for preparing a porous carbon nitride material according to claim 1 or 2, wherein the muffle furnace is heated to 550 ℃ at a rate of 6 ℃/min and is kept for 4 h.

5. A porous carbon nitride material produced by the production method according to any one of claims 1 to 4.

6. The use of the porous carbon nitride material according to claim 5 in catalyzing photodegradation of rhodamine B.

Technical Field

the invention belongs to the technical field of preparation and application of materials, and particularly relates to a preparation method of a porous carbon nitride material, the porous carbon nitride material and application of the porous carbon nitride material.

Background

The carbon nitride is a novel photocatalytic material and has the advantages of high stability, low price, environmental protection and the like. The band gap width of the carbon nitride is about 2.7eV, the carbon nitride can absorb more visible light and has stronger oxidation-reduction capability, so the carbon nitride has wide application prospects in the aspects of photocatalytic degradation of organic pollutants, photocatalytic decomposition of water for hydrogen production, photocatalytic reduction of carbon dioxide and the like. The carbon nitride is prepared by thermal polymerization of melamine or dicyandiamide generally, but the carbon nitride prepared by the method has small specific surface area and lower activity. The carbon nitride prepared by thermal polymerization of urea or thiourea has a large specific surface area, but the yield of the product is about 5% and the yield of the carbon nitride is very low. Therefore, how to efficiently prepare carbon nitride with large specific surface area has been the focus of research.

The preparation of porous carbon nitride by a template method is a common method. The patent with publication number CN108654672A discloses a preparation method and application of a formic acid hydrogen production catalyst, which uses mesoporous silicon as a hard template, carbon tetrachloride as a carbon source and ethylenediamine as a nitrogen source to synthesize mesoporous carbon nitride, and then uses hydrofluoric acid to etch and remove the template, and uses strong corrosive hydrofluoric acid in the preparation process, which is not beneficial to environmental protection. Wang and Wang, etc. adopt a block copolymer and a nonionic surfactant as a soft template to prepare the nano-porous carbon nitride (WangY, Wang X, Antoniettim, Zhang Y. ChemSusChem,2010,3(4): 435-439), but the soft template has higher price and is not beneficial to large-scale production. The patent with publication number CN107758635A discloses a controlled synthesis method of graphene-like carbon nitride ultrathin nanosheets, which is to obtain carbon nitride nanosheets by taking melamine, cyanuric acid and dicyandiamide as raw materials and boric acid or boron oxide as a form control agent through hydrothermal and microwave radiation. The patent with publication number CN105664835A discloses a method for batch preparation of porous carbon nitride material assisted by organic carboxylic acid, which uses melamine as raw material, and organic carboxylic acid such as acetic acid, oxalic acid, benzoic acid or salicylic acid as auxiliary raw material, and adopts a hydrothermal-calcination two-step method to obtain porous carbon nitride material. However, the organic acid or the inorganic acid is only used as a pore-forming agent, which causes a certain waste, not only pollutes the environment, but also increases the production cost. Therefore, the development of a method for efficiently preparing carbon nitride, which has low cost, environmental friendliness and simple process, is of great significance.

Disclosure of Invention

The invention aims to provide a preparation method of a porous carbon nitride material, the porous carbon nitride material and application thereof, wherein the method can simplify the preparation process, reduce the production cost and the pollution to the environment and improve the product yield; the prepared porous carbon nitride material has large comparative area and can effectively catalyze photodegradation of rhodamine B.

In order to achieve the aim, the preparation method of the porous carbon nitride material comprises the following steps:

Grinding the metered cyanuric acid and the small molecular nitrogen-containing compound in a mortar, transferring the obtained solid mixture into a crucible with a cover, placing the crucible in a muffle furnace for roasting, heating the muffle furnace to 540-560 ℃ at the speed of 3-10 ℃/min, preserving the temperature for 3-5 h, and naturally cooling to obtain the porous carbon nitride material; the mass ratio of the cyanuric acid to the small molecular nitrogen-containing compound is 1: (1-6).

preferably, the small molecular nitrogen-containing compound is one or more of urea, thiourea, dicyandiamide and cyanamide;

Preferably, the mass ratio between the cyanuric acid and the small molecule nitrogen-containing compound is 1: 3.

preferably, the temperature of the muffle furnace is increased to 550 ℃ at the speed of 6 ℃/min, and the temperature is kept for 4 h.

A porous carbon nitride material is prepared by the preparation method.

The porous carbon nitride material prepared by the preparation method is applied to catalytic photodegradation of rhodamine B.

The invention takes cheap cyanuric acid and small molecular nitrogen-containing compounds as raw materials, and adopts a one-step thermal polymerization method to prepare the porous carbon nitride. By changing the types and the adding amount of the small molecular nitrogen-containing compounds, a plurality of porous carbon nitride materials with different morphological structures and specific surface areas are prepared. In the preparation process, the alkaline small molecule nitrogen-containing compound and cyanuric acid are subjected to acid-base neutralization reaction to generate cyanurate, the cyanurate is further dehydrated and deaminated along with the temperature rise to form a multi-membered ring, and small molecules such as water, ammonia and the like escape in a gas form to play a pore-forming role, so that the porous carbon nitride material is formed finally.

Compared with the prior art, the method takes low-cost and nontoxic small-molecule nitrogen-containing compounds such as cyanuric acid, urea and the like as raw materials to prepare the porous carbon nitride, so that the production cost can be obviously reduced; the porous carbon nitride is directly obtained after calcination, no post-treatment is needed, the reaction is completed in one step, the production process is simplified, and the pollution to the environment is reduced; in addition, the yield of the porous carbon nitride material prepared by the method is up to 45%, and the product yield is improved. The method is carried out under normal pressure, does not need to use complex equipment, and is easy for industrial production. The porous carbon nitride material prepared by the preparation method has large specific surface area, has higher catalytic activity and better repeatability when being used as a catalyst for photodegradation of rhodamine B, and has potential utilization value in the aspect of sewage treatment.

Drawings

FIG. 1 is an X-ray diffraction pattern of a porous carbon nitride material prepared in accordance with example one of the present invention;

FIG. 2 is an infrared spectrum of a porous carbon nitride material prepared according to the first embodiment of the present invention;

FIG. 3 is an isothermal adsorption-desorption curve of the porous carbon nitride material prepared in the first embodiment of the present invention;

FIG. 4 is a TEM image of the porous carbon nitride material prepared in the first example of the present invention;

FIG. 5 is an activity diagram of the porous carbon nitride material prepared in the first embodiment of the invention catalyzing photodegradation of rhodamine B solution;

FIG. 6 is a repeated diagram of the porous carbon nitride material prepared in the first embodiment of the invention catalyzing photodegradation of rhodamine B solution.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples.