阅读说明：本技术 一种可见光吸收增强石墨相氮化碳材料的制备方法 (Preparation method of visible light absorption enhanced graphite phase carbon nitride material ) 是由 张宪民 孔凡 秦高梧 于 2019-10-23 设计创作，主要内容包括：一种可见光吸收增强石墨相氮化碳材料的制备方法,按以下步骤进行：(1)将三聚氰胺置于坩埚中,密封后盖上坩埚盖,置于加热炉内；(2)先升温至300±2℃时,升温速度4±0.1℃/min；(3)继续升温至400±2℃,升温速度在2±0.1℃/min；(4)继续升温至500～600℃,控制升温速度在4±0.1℃/min；(5)在500～600℃保温2～4h,随炉冷却,取出后研磨。本发明的方法不需要进行二次高温刻蚀处理,也没使用任何有机溶剂或强酸等,所制备的氮化碳纳米片可见光吸收性能强,光催化性能优越。(A preparation method of a graphite-phase carbon nitride material with enhanced visible light absorption comprises the following steps: (1) placing melamine in a crucible, sealing, covering a crucible cover, and placing in a heating furnace; (2) firstly, heating to 300 +/-2 ℃, wherein the heating speed is 4 +/-0.1 ℃/min; (3) continuously heating to 400 +/-2 ℃, wherein the heating speed is 2 +/-0.1 ℃/min; (4) continuously heating to 500-600 ℃, and controlling the heating speed to be 4 +/-0.1 ℃/min; (5) preserving heat for 2-4 h at 500-600 ℃, cooling along with the furnace, taking out and grinding. The method does not need secondary high-temperature etching treatment, does not use any organic solvent or strong acid and the like, and the prepared carbon nitride nanosheet is high in visible light absorption performance and excellent in photocatalytic performance.)

1. A preparation method of a graphite-phase carbon nitride material with enhanced visible light absorption is characterized by comprising the following steps:

(1) placing melamine in a crucible, sealing, covering a crucible cover, and placing in a heating furnace;

(2) heating the materials in the crucible to 300 +/-2 ℃ by a heating furnace, and controlling the heating speed to be 4 +/-0.1 ℃/min;

(3) continuously heating the materials in the crucible to 400 +/-2 ℃, and controlling the heating speed to be 2 +/-0.1 ℃/min;

(4) continuously heating the materials in the crucible to 500-600 ℃, and controlling the heating speed to be 4 +/-0.1 ℃/min;

(5) and (3) preserving the heat of the materials in the crucible at 500-600 ℃ for 2-4 h, then cooling the materials to the normal temperature along with the furnace, taking out the materials, and grinding the materials in the crucible to prepare the visible light absorption enhanced graphite phase carbon nitride material.

2. The method for preparing a graphite-phase carbon nitride material with enhanced visible light absorption according to claim 1, wherein in the step (1), the sealing is performed by wrapping with tin foil.

3. The method for producing a graphite-phase carbon nitride material enhanced in visible light absorption according to claim 1, wherein in the step (5), the grinding means crushing the agglomerated particles.

4. The method according to claim 1, wherein the graphite-phase carbon nitride material having enhanced visible light absorption has a yellow appearance.

5. A method of using the visible light absorption enhanced graphite phase carbon nitride material of claim 1 for organic dye degradation.

Technical Field

The invention belongs to the technical field of modification of graphite-like carbon nitride, and particularly relates to a preparation method of a visible light absorption enhanced graphite-phase carbon nitride material.

Background

To date, a variety of conventional semiconductors have been extensively studied for photocatalytic degradation of organic contaminants, such as TiO₂And ZnO; however, the application of the above mentioned photocatalysts is practically limited only by the absorption of the ultraviolet components in the solar spectrum and their rapid e-h + recombination; with respect to the problems of conventional semiconductor photocatalysts, despite great progress,photocatalytic technology is still limited by the lack of efficient and practical photocatalysts; this has prompted a great deal of research into the pursuit of efficient, stable, low cost and environmentally friendly photocatalysts.

Among many semiconductor photocatalysts, the polymer graphite carbon nitride (g-C)₃N₄) Due to its extraordinary chemical stability, no metal component, 2D structure, visible light response, considerable research interest has been aroused; however, due to the smaller specific surface area and the original g-C₃N₄The fast recombination rate of the charge carriers of (a) results in a low photocatalytic efficiency; to date, several strategies have been proposed to address g-C₃N₄Including metal deposition (Pd, Pt and Au), doping with non-metal elements (B, I and P), defect control, and g-C based₃N₄Of (e.g. with TiO)₂，Cu₂O and ZnO).

For lamellar g-C₃N₄Materials, g-C due to exposed edges, limited boundaries, severe clustering and re-stacking between sheets₃N₄The large number of photocatalytically active sites in the material remains restricted, resulting in poor photocatalytic performance; enhancing the absorption of visible light to promote the efficiency of photogenerated electron-hole separation has proven to be an effective way to ameliorate the above disadvantages; therefore, it is necessary to develop a simple, efficient and environmentally friendly method for preparing graphite-phase carbon nitride material with enhanced red shift of absorption band edge and high activity.

Disclosure of Invention

Aiming at the existing g-C₃N₄The present invention is directed to providing a graphite phase carbon nitride (g-C) with enhanced visible light absorption₃N₄) The preparation method of the material simplifies the process under the environment-friendly condition and enhances the visible light absorption performance of the product by controlling the heating rate and the reaction temperature when the melamine is calcined.

The method of the invention is carried out according to the following steps:

1. placing melamine in a crucible, sealing, covering a crucible cover, and placing in a heating furnace;

2. heating the materials in the crucible to 300 +/-2 ℃ by a heating furnace, and controlling the heating speed to be 4 +/-0.1 ℃/min;

3. continuously heating the materials in the crucible to 400 +/-2 ℃, and controlling the heating speed to be 2 +/-0.1 ℃/min;

4. continuously heating the materials in the crucible to 500-600 ℃, and controlling the heating speed to be 4 +/-0.1 ℃/min;

5. and (3) preserving the heat of the materials in the crucible at 500-600 ℃ for 2-4 h, then cooling the materials to the normal temperature along with the furnace, taking out the materials, and grinding the materials in the crucible to prepare the visible light absorption enhanced graphite phase carbon nitride material.

The sealing is performed by wrapping with tin foil.

The above-mentioned grinding means to break up agglomerated particles.

The visible light absorption enhanced graphite phase carbon nitride material has a yellow appearance.

The visible light absorption enhanced graphite-phase carbon nitride material is used as a catalyst for degrading organic dye.

The method directly prepares graphite-phase carbon nitride (g-C) by directly thermally treating raw material melamine and performing thermal polymerization₃N₄) A material; in the temperature rising process, the temperature rising rate is reduced within 300-400 ℃, in the thermal shrinkage process of melamine, the temperature is within 300-400 ℃ which is an important condensation stage, and the melamine can be fully condensed in the slow temperature rising process; in addition, the method does not need secondary high-temperature etching treatment, and does not use any organic solvent or strong acid and the like, so the method has the advantages of environmental friendliness, simplicity, convenience and high efficiency; meanwhile, the carbon nitride nanosheet prepared by the method is high in visible light absorption performance, excellent in photocatalytic performance and wide in application prospect.

Drawings

FIG. 1 is an X-ray diffraction pattern of a visible light absorption enhanced graphitic carbon nitride material according to an embodiment of the present invention; in the figure, CN-500, CN-550 and CN-600 are respectively embodiment 1, embodiment 2 and embodiment 3;

FIG. 2 is a TEM image of a visible light absorption enhanced graphitic carbon nitride material according to an embodiment of the present invention; in the figure, (a) is example 1, (b) is example 3;

FIG. 3 is a fluorescence spectrum of a visible light absorption enhanced graphite phase carbon nitride material in an example of the present invention; in the figure, CN-500, CN-550 and CN-600 are respectively embodiment 1, embodiment 2 and embodiment 3;

FIG. 4 is a graph of the UV-VIS diffuse reflectance spectrum of a visible light absorption enhanced graphite phase carbon nitride material in an example of the present invention; in the figure, N-500, CN-550 and CN-600 are respectively embodiment 1, embodiment 2 and embodiment 3;

FIG. 5 is a Fourier transform infrared spectrum of a visible light absorption enhanced graphite phase carbon nitride material in an embodiment of the present invention; in the figure, N-500, CN-550 and CN-600 are respectively embodiment 1, embodiment 2 and embodiment 3;

FIG. 6 is a graph of photocatalytic time-degradation rate for photocatalytic degradation of rhodamine B in a visible light absorption enhanced graphite-phase carbon nitride material in an embodiment of the present invention; in the figure, N-500, CN-550 and CN-600 are respectively example 1, example 2 and example 3.

Detailed Description

The applicant shall now describe the technical solutions of the present invention in detail with reference to specific embodiments so as to enable those skilled in the art to further understand the present invention, but the following embodiments shall not be construed as limiting the scope of the present invention in any way.

In the examples of the present invention, XRD measurements were carried out on the samples using an X-ray diffractometer model Bruker-D8, Germany (Cu K α, λ 0.154nm), with a step size of 0.02 °. s^-1The operating voltage and the operating current were 15kV and 30mA, respectively).

In the embodiment of the invention, the American Bruker IFS 66V S is adopted^-1The type infrared spectrometer performs an FT-IR test on the sample.

In the examples of the present invention, the morphology of the sample was observed by using a transmission electron microscope (TEM, Tecnai G20 model) of FEI corporation, usa.

In the embodiment of the invention, a Lambda 750S type ultraviolet-visible spectrophotometer is adopted to carry out ultraviolet-visible solid diffuse reflection spectrum test on a sample (barium sulfate is used as a standard reflection reference in the test, and the scanning wavelength is 200-800 nm).

In the embodiment of the invention, an LS-55 fluorescence spectrophotometer is adopted to carry out fluorescence spectrum test on the sample.

In the embodiment of the invention, the graphite-phase carbon nitride material with enhanced visible light absorption is used as a catalyst, the photoactivity of the graphite-phase carbon nitride material is evaluated by degrading rhodamine B through visible light catalysis, and the experimental process is as follows: weighing 0.05g of catalyst, and preparing 50ml of rhodamine B solution with the concentration of 10 mg/L; under the condition of magnetic stirring, placing the catalyst in a rhodamine B solution, and carrying out dark treatment on the mixed solution for 30min to achieve adsorption-desorption balance; and (3) irradiating the mixed solution by using a 350W xenon lamp as a light source, filtering light with the wavelength of below 420nm by using a 420nm filter, taking 4ml of the rhodamine B solution subjected to catalytic degradation every 10min until 1h, and respectively carrying out an ultraviolet-visible absorption test on each taken solution to evaluate the degradation performance.