CN109535421B

CN109535421B - Oxazinyl carbon nitrogen polymer, preparation method and application thereof

Info

Publication number: CN109535421B
Application number: CN201811645199.8A
Authority: CN
Inventors: 霍宇凝; 李蕙帆; 杨玉萍; 丁梦娜; 罗柳林; 邹泉; 张子平; 裴文凯; 李和兴
Original assignee: Shanghai Normal University
Current assignee: Shanghai Normal University
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2021-06-18
Anticipated expiration: 2038-12-29
Also published as: CN109535421A

Abstract

The invention relates to the field of semiconductor photocatalytic materials, in particular to an oxazinyl carbon nitrogen polymer, a preparation method thereof and application of the oxazinyl carbon nitrogen polymer as a photocatalyst. The oxazine-based carbon nitrogen polymer is a rod-like heptazine-triazine-based carbon nitrogen polymer formed by spontaneous oriented growth of a lamellar heptazine-based carbon nitrogen polymer. The charge carrier recombination rate of the oxazinyl carbon-nitrogen polymer is low, the rod-shaped structure can effectively capture light energy and bacteria, the photocatalytic activity and the stability are excellent, the cyclic use is realized, and the practical application prospect is good.

Description

Oxazinyl carbon nitrogen polymer, preparation method and application thereof

Technical Field

The invention relates to the field of semiconductor photocatalytic materials, in particular to an oxazinyl carbon nitrogen polymer, a preparation method thereof and application of the oxazinyl carbon nitrogen polymer as a photocatalyst.

Background

The problem of treating environmental pollutants by using semiconductor photocatalysts is increasingly favored by scientists. As a new sterilization technology, compared with the sterilization by ultraviolet rays, ozone, disinfectors and the like which are widely used at present, the photocatalytic sterilization can effectively prevent the introduction of the ultraviolet rays and toxic gases from damaging human bodies, and prevent the formation of toxic byproducts and the harm to the environment and the human bodies. Meanwhile, the photocatalytic sterilization utilizes sunlight to provide energy, and has the advantages of high efficiency, broad spectrum, difficult generation of drug resistance, difficult secondary pollution and the like. However, P25 TiO which is widely researched and applied at present₂The ultraviolet light can only be excited by ultraviolet light due to wide forbidden band width, but the ultraviolet light only occupies a small part (less than 5%) of sunlight, and simultaneously, the quantum efficiency of the ultraviolet light is very low due to high recombination rate of photon-generated carriers. Therefore, how to obtain a visible-light-driven photocatalyst which can fully utilize sunlight and has high carrier mobility has become an important research field.

The currently graphitized C₃N₄(g-C₃N₄) As a nonmetal photocatalyst, the photocatalyst has the advantages of simple preparation method, cheap and easily-obtained raw materials, capability of absorbing visible light and no secondary pollution, thereby becoming a research hotspot. However, such a high degree of polymerization of g-C₃N₄The surface active sites are few, the carrier recombination rate is high, and the quantum efficiency is low. At the same time, most of g-C is currently available₃N₄Being a lamellar structure, it is difficult to effectively absorb sunlight and trap bacteria. The carbon-nitrogen polymer with low polymerization degree can effectively promote the photocatalytic activity because more catalytic active sites are exposed on the surface. However, the current knowledge on the growth control of the oligomeric carbon nitrogen polymer is still relatively shallow, and particularly, the spontaneously oriented polymerized azinyl oligomeric carbon nitrogen polymer is not reported.

Disclosure of Invention

The invention aims to provide a heptazine-triazine-based carbon nitrogen copolymer with a rod-like structure, which is formed by spontaneous oriented growth of a lamellar structure heptazine-based carbon nitrogen polymer.

The invention also provides a preparation method of the self-oriented polymerized oxazinyl carbon nitrogen polymer, and the oxazinyl carbon nitrogen polymer with remarkably improved photocatalytic bactericidal activity can be obtained by the method.

In order to achieve the purpose, the invention adopts a technical scheme as follows:

an oxazinyl carbon nitrogen polymer which is a rod-like heptazine-triazine based carbon nitrogen polymer grown spontaneously and directionally from a lamellar heptazine-based carbon nitrogen polymer.

The oxazinyl carbon nitrogen polymer carrier has low recombination rate, the rod-shaped structure can effectively capture light energy and bacteria, and the oxazinyl carbon nitrogen polymer carrier has excellent photocatalytic activity and stability, can be recycled and has good practical application prospect.

Preferably, the lamellar structure heptazinyl carbon nitrogen polymer has a thickness of 5-15 microns and a carbon-nitrogen ratio of 0.67; the length of the heptazine-triazine carbon nitrogen polymer with the rod-shaped structure is 10-20 micrometers, and the diameter of the heptazine-triazine carbon nitrogen polymer is 50-75 nanometers.

Further, the thickness of the heptazinyl carbon nitrogen polymer of the lamellar structure is preferably 10 micrometers.

Further, the length of the heptazine-triazine-based carbon nitrogen polymer with the rod-like structure is preferably 12-16 micrometers, and the diameter of the heptazine-triazine-based carbon nitrogen polymer is preferably 55 nanometers.

Preferably, the preparation method of the oxazinyl carbon nitrogen polymer comprises the following steps:

step 1: fully dissolving melamine and water to obtain suspension;

step 2: roasting the suspension to obtain solid particles;

and step 3: and cooling the solid particles to room temperature and grinding to obtain the catalyst.

The preparation method is very simple and convenient, the used raw materials are simple and easy to obtain, the price is low, the generation of polluting byproducts can be effectively avoided, no secondary pollution is caused in the sterilization process, and no external energy supply is required. The oxazinyl carbon-nitrogen polymer is simply and rapidly prepared by taking melamine as a precursor through a high-temperature roasting method. The water used in the present invention is preferably deionized water.

Preferably, the feeding mass ratio of the melamine to the water in the step 1 is 3: 2-8; the dissolving temperature of melamine and water is 15-75 ℃; the dissolving time of the melamine and the water is preferably 10 to 50 minutes.

Further, in the step 1, the feeding mass ratio of melamine to water is preferably 3:4, 3:5, 1:2, and most preferably 1:2, and in the ratio range, the prepared oxazinyl carbon nitrogen polymer has no impurities or very little impurities.

Further, in the step 1, the dissolving temperature of the melamine and the water is preferably 15-30 ℃, and most preferably 25 ℃. The self-oriented polymerized oxazinyl carbon nitrogen polymer can be obtained by controlling the temperature in the preferred temperature range.

Further, in the step 1, the dissolving time of the melamine and the water is preferably 30 minutes.

Further, in the step 2, the baking temperature of the suspension is 400-500 ℃, and preferably the baking temperature is 450 ℃.

Further, in the step 2, the baking time of the suspension is 2 to 6 hours, preferably 4 hours.

Further, in the step 2, the heating rate of the suspension liquid in the baking process is 3-8 ℃/min, and preferably the heating rate is 5 ℃/min.

The method takes melamine as a precursor, and the oxazinyl carbon nitrogen polymer is simply and rapidly prepared by a high-temperature roasting method. The prepared carbon-nitrogen polymer is compared with the traditional C₃N₄More functional groups can be exposed on the surface, obvious defects also exist in chain segment terminals, catalytic active sites of the catalyst are increased, and in addition, the separation of photon-generated carriers can be effectively improved by a flaky and rodlike coexisting nano structure. In addition, the rodlike structure of the carbon-nitrogen oligomer can effectively capture light energy and bacteria, so that the light energy utilization rate can be improved, the conduction rate of photo-generated electrons can be increased, the carbon-nitrogen oligomer can effectively contact with the bacteria, and the photocatalytic activity can be enhanced.

Preferably, the oxazinyl carbon nitrogen polymer has photocatalytic activity in a visible light band, and can be used as a photocatalyst for photocatalytic sterilization.

The oxazinyl carbon nitrogen polymer prepared by the method has low carbon nitrogen ratio, is a spontaneously oriented polymerized oxazinyl carbon nitrogen polymer, and has excellent photocatalytic activity in a visible light waveband.

The photocatalytic sterilization process adopts visible light, and the bacteria are escherichia coli.

Advantageous effects

Due to the implementation of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the preparation method is very simple and convenient, the used raw materials are simple and easy to obtain, the price is low, the generation of polluting byproducts can be effectively avoided, no secondary pollution is caused in the sterilization process, and no external energy supply is required. The prepared oxazinyl carbon nitrogen polymer photocatalyst is low in carrier recombination rate, the rod-shaped structure can effectively capture light energy, and the photocatalyst has excellent photocatalytic activity and stability, can be recycled, and has a good practical application prospect.

2. The method takes melamine as a precursor, and the oxazinyl carbon nitrogen polymer is simply and rapidly prepared by a high-temperature roasting method. The prepared carbon-nitrogen polymer is compared with the traditional C₃N₄More functional groups can be exposed on the surface, obvious defects also exist in chain segment terminals, catalytic active sites of the catalyst are increased, and in addition, the separation of photon-generated carriers can be effectively improved by a flaky and rodlike coexisting nano structure. In addition, the rodlike structure of the carbon-nitrogen oligomer can effectively capture light energy and bacteria, so that the light energy utilization rate can be improved, the conduction rate of photo-generated electrons can be increased, the carbon-nitrogen oligomer can effectively contact with the bacteria, and the photocatalytic activity can be enhanced.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1a is an X-ray diffraction (XRD) pattern of samples prepared in example 1 and comparative examples 1-2;

FIG. 1b is an X-ray diffraction (XRD) pattern of a sample prepared in examples 1-3;

FIG. 2a is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 1;

FIG. 2b is an enlarged partial photograph of FIG. 2 a;

FIG. 2c is an enlarged partial photograph of FIG. 2 b;

FIG. 2d is a Scanning Electron Microscope (SEM) photograph of the sample prepared in comparative example 1;

FIG. 2e is a Scanning Electron Microscope (SEM) photograph of the sample prepared in comparative example 2;

FIG. 2f is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 2;

FIG. 2g is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 3;

FIG. 3a is a high resolution Transmission Electron Microscope (TEM) photograph of the sample prepared in example 1;

FIG. 3b is an enlarged partial photograph of FIG. 3 a;

FIG. 4a is a 13C solid nuclear magnetic resonance (13CNMR) carbon spectrum of the samples prepared in example 1, comparative example 1 and comparative example 2;

FIG. 4b is a fluorescence spectrum of the samples prepared in example 1 and comparative example 1;

FIG. 5a is an infrared spectroscopic analysis of samples prepared in example 1, comparative example 1 and comparative example 2;

FIG. 5b is an infrared spectroscopic analysis of samples prepared in examples 1 to 3;

FIG. 5c is an infrared spectroscopic analysis of samples prepared in examples 6-8;

FIG. 6a is a UV-VIS absorption spectrum of samples prepared in example 1 and comparative example 1;

FIG. 6b is a graph showing UV-visible absorption spectra of samples prepared in examples 1-3;

FIG. 7 is a comparison of the photocatalytic activity of example 1 and comparative examples 1 and 2;

FIG. 8 is a comparison of photocatalytic activities of examples 1 to 3;

FIG. 9 is a comparison of the photocatalytic activity of examples 1, 4, 5;

FIG. 10 is a comparison of the photocatalytic activities of examples 1, 6 to 8.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

The invention will now be described in further detail, clearly and completely, with reference to specific examples, which are given by way of illustration only and are not intended to limit the invention:

the oxazinyl carbon nitrogen polymer photocatalyst prepared by the invention is characterized by the following means: analyzing the composition of a sample by adopting a Vario EL cube type element analyzer; performing structural analysis by using a Rigaku D/Max-RB type X-ray diffractometer (XRD); analyzing the morphological structure of the sample by adopting a JEOL JSM-6380LV type Scanning Electron Microscope (SEM) and a JEOL TEM 2011 type high-resolution Transmission Electron Microscope (TEM); analyzing the structure of the sample by AvanceIII HD 600 type solid Nuclear Magnetic Resonance (NMR); performing fluorescence spectrum test on the prepared solid catalyst sample by adopting a Varian Cary-Eclipse 500 type spectrometer; performing infrared spectrum test by using PerkinElmer-Frontier; and performing an ultraviolet visible diffuse reflection test by adopting a spectrophotometer with the model of UV-2450.

The experimental process of killing escherichia coli by the oxazinyl carbon nitrogen polymer under visible light in the embodiment of the invention is as follows: in a thermostatic water bath at 25 ℃, 15mg of photocatalyst was added to 15mL of an E.coli solution with a bacterial concentration of 0.1(OD) and mixed well. Then, a 300W xenon lamp is used as a light source for irradiation, and light with the wavelength less than 420 nanometers is filtered out for carrying out photocatalytic reaction for 90 minutes. 100uL of the solution was evenly spread on an agar plate every 30 minutes, and the plate was incubated in an incubator at 37 ℃ for 24 hours, followed by observing the growth of colonies and counting. In addition, the same prepared solution was put in the dark to perform an antibacterial test, and this solution was used as a control. The higher the bacteria killing rate is, the stronger the photocatalytic activity is, so the photocatalytic activity is obtained from the bacteria killing rate.

Example 1

This example provides an oxazinyl carbon nitrogen polymer prepared by the following steps:

weighing 15.0g of melamine in a crucible, weighing 30mL of distilled water, adding the distilled water into the crucible, placing the crucible at 25 ℃, stirring for 30 minutes to fully dissolve the melamine, roasting at 450 ℃ for 4 hours (the heating rate is 5 ℃/min), naturally cooling to room temperature, and grinding and collecting to obtain a white solid, wherein the white solid is the oxazinyl carbon nitrogen polymer.

The oxazinyl carbon nitrogen polymer prepared from example 1 was rod-like in length of about 20 microns, 55 nm in diameter, 0.67 carbon to nitrogen ratio, and photocatalytic in nature, grown on a lamellar structure.

The results of the elemental analysis are shown in Table 1, where it can be seen that the sample prepared in example 1 has a carbon to nitrogen ratio of 0.67, which is lower than the theoretical C₃N₄0.75, indicating that the polymerization degree of the azinyl carbon nitrogen polymer prepared in example 1 is low, but the nitrogen content is higher than the theoretical C₃N₄The existence of more nitrogen defects is proved to be beneficial to improving the migration of photon-generated carriers so as to improve the photocatalytic activity.

Fig. 1a is an X-ray diffraction (XRD) pattern of the samples prepared in example 1, comparative example 1 and comparative example 2, and as shown in fig. 1a, shows that the diffraction peak of the sample prepared in example 1 is similar to that of melem, indicating that the sample is a carbon-nitrogen oligomer, which can expose more active sites to improve photocatalytic activity.

Fig. 2a is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 1, fig. 2b is a partially enlarged photograph of fig. 2a, and fig. 2c is a partially enlarged photograph of fig. 2b, which shows that the sample prepared in example 1 is a material in which a rod structure is grown on a sheet structure, and the rod length is about 20 μm, as shown in fig. 2a, 2b, and 2 c.

Fig. 3a is a high-resolution Transmission Electron Microscope (TEM) photograph and fig. 3b is a partial enlarged photograph of fig. 3a of the sample prepared in example 1, as shown in fig. 3a and 3b, indicating that the rod-shaped diameter of the sample prepared in example 1 is 55 nm.

FIG. 4a is a graph showing samples prepared in example 1 and comparative examples 1 to 2¹³C solid nuclear magnetic resonance (¹³C NMR) carbon spectrum of example 1 and comparative example 1 from the top down as shown in FIG. 4aComparative example 2¹³C solid nuclear magnetic resonance (¹³CNMR) carbon spectrum. FIG. 4a shows that the sample prepared in example 1 is a carbon-nitrogen polymer based on a triazine structure and the migration of chemical shifts indicates the incorporation of oxygen in the structure.

Fig. 4b shows fluorescence spectra of samples prepared in example 1 and comparative example 1, and as shown in fig. 4b, it is demonstrated that the sample prepared in example 1 has a high carrier separation efficiency and can improve photocatalytic activity.

FIG. 5a is an infrared spectroscopic analysis of the samples prepared in example 1, comparative example 1 and comparative example 2, showing that the sample prepared in example 1 is an oxygen-doped carbon-nitrogen polymer containing hydroxyl groups, carbon-oxygen double bonds and single bonds, as shown in FIG. 5 a.

Fig. 6a is an ultraviolet-visible absorption spectrum of the samples prepared in example 1 and comparative example 1, and as shown in fig. 6a, it indicates that the sample prepared in example 1 is a rod-like structure formed by sheet-like directional polymerization, and has stronger light absorption, higher light energy utilization rate and promotion effect on enhancing photocatalytic activity compared with comparative example 1 with a single sheet structure.

FIG. 7 is a comparison of the photocatalytic activity of example 1 and comparative examples 1 and 2; FIG. 8 is a comparison of photocatalytic activities of examples 1 to 3; FIG. 9 is a comparison of the photocatalytic activity of examples 1, 4, 5; FIG. 10 is a comparison of the photocatalytic activities of examples 1, 6 to 8.

As shown in fig. 7 to 10, this example 1 is shown to have better photocatalytic activity than the other examples.

Comparative example 1

15.0g of melamine was weighed into a crucible, calcined at 450 ℃ for 4 hours (at a rate of 5 ℃/min) and then allowed to cool to room temperature, and ground to collect a white solid which was the oxazinyl carbon nitrogen polymer.

The oxazinyl carbon nitrogen polymer prepared in comparative example 1 had a carbon to nitrogen ratio of 0.66, was lamellar in structure and exhibited photocatalytic activity.

The results of the elemental analysis are shown in Table 1, where it can be seen that comparative example 1 was madeThe prepared sample has a carbon-nitrogen ratio of 0.66 and a carbon-nitrogen ratio lower than theoretical C₃N₄It is shown that the sample prepared in comparative example 1 has a low degree of polymerization and a nitrogen content higher than that of conventional C₃N₄The existence of more nitrogen defects is proved to be beneficial to improving the migration of photon-generated carriers so as to improve the photocatalytic activity.

Fig. 1a x-ray diffraction (XRD) pattern shows that the diffraction peak of the sample prepared in comparative example 1 is similar to that of melem, indicating that the sample prepared in comparative example 1 is a carbon-nitrogen oligomer, which can expose more active sites to improve photocatalytic activity.

Fig. 2d is a Scanning Electron Microscope (SEM) photograph of the sample prepared in comparative example 1, as shown in fig. 2d, indicating that the sample prepared in comparative example 1 has a mainly lamellar structure.

FIG. 4a¹³C solid nuclear magnetic resonance (¹³CNMR) carbon spectrum showed that the sample prepared in comparative example 1 was a carbon-nitrogen polymer based on a triazine structure, and the migration of chemical shifts indicated that oxygen was incorporated in the structure.

Fig. 4b is a fluorescence spectrum illustrating that the sample prepared in comparative example 1 has a low carrier separation efficiency and weak photocatalytic activity.

FIG. 5a is an infrared spectroscopic analysis showing that the sample prepared in comparative example 1 is an oxygen-doped carbon-nitrogen polymer and the main oxygen functional group is a hydroxyl group.

FIG. 6a is a UV-visible absorption spectrum of samples prepared in example 1 and comparative example 1, as shown in FIG. 6a, indicating that the light absorption of the azinyl carbon nitrogen polymer prepared in comparative example 1 with lamellar structure is weaker and less active than the sample prepared in example 1 with rod-like structure formed by lamellar oriented polymerization.

Fig. 7 shows that the sample prepared in comparative example 1 has a certain photocatalytic activity.

Fig. 4b shows fluorescence spectra of the samples prepared in example 1 and comparative example 1, and as shown in fig. 4b, the carrier separation efficiency of the sample prepared in example 1 is higher than that of comparative example 1.

Fig. 6a is a uv-vis absorption spectrum of the samples prepared in example 1 and comparative example 1, as shown in fig. 6a, indicating that the sample prepared in example 1 has stronger light absorption than the sample prepared in comparative example 1.

Comparative example 2

This example provides a carbon nitride polymer prepared by the following steps:

weighing 15.0g of melamine in a crucible, roasting at 550 ℃ for 4 hours (the heating rate is 5 ℃/min), then naturally cooling to room temperature, grinding and collecting white solid to obtain the carbon nitride.

The carbon nitride polymer prepared by comparative example 1 had a carbon to nitrogen ratio of 0.72, a lamellar structure, and low photocatalytic activity.

Elemental analysis results referring to table 1, the sample prepared in comparative example 2 had a carbon to nitrogen ratio of 0.72, indicating that the sample prepared in comparative example 2 was a highly polymerized structure.

FIG. 1 aX-ray diffraction (XRD) pattern showing that the sample prepared in this comparative example 2 is highly polymerized C₃N₄。

Fig. 2e is a Scanning Electron Microscope (SEM) photograph of the sample prepared in comparative example 2, showing that the sample prepared in comparative example 2 has a lamellar structure.

FIG. 4a¹³C solid nuclear magnetic resonance (¹³CNMR) carbon spectrum showed that the sample prepared in comparative example 2 was a highly polymerized carbon nitrogen polymer based on a heptazine structure.

FIG. 5a Infrared Spectroscopy (IR Spectroscopy) shows that the sample prepared in comparative example 2 is a highly polymerized carbon nitride polymer with no significant oxygen structure.

Fig. 7 shows that the photocatalytic activity of the sample prepared in comparative example 2 is significantly lower than that of example 1.

TABLE 1

Table 1 shows the results of elemental analyses of the oxazinyl carbon nitrogen polymers prepared in example 1 and comparative examples 1-2.

As can be seen from table 1, the carbon-nitrogen ratio of the product prepared in comparative example 2 was 0.72, indicating that the product prepared in comparative example 2 is a highly polymerized structure. The carbon-nitrogen ratios of the products prepared in the example 1 and the comparative example 1 are 0.67 and 0.66 respectively, and the carbon-nitrogen ratio is lower than that of the product prepared in the comparative example 2, so that the polymerization degree of the products prepared in the example 1 and the comparative example 1 is lower, but the nitrogen content is higher than that of the product prepared in the comparative example 2, and the products prepared in the example 1 and the comparative example 1 have more nitrogen defects, and are favorable for improving the migration of photo-generated carriers so as to improve the photocatalytic activity.

FIG. 1a is an X-ray diffraction (XRD) pattern of the samples prepared in example 1 and comparative examples 1-2, and as shown in FIG. 1a, the X-ray diffraction (XRD) patterns of the samples prepared in example 1, comparative example 1 and comparative example 2 are sequentially from top to bottom. FIG. 1a shows that the diffraction peaks of the samples prepared in example 1 and comparative example 1 are similar to those of melem, and illustrates that the samples prepared in example 1 and comparative example 1 are carbon-nitrogen oligomers, and the sample prepared in comparative example 2 is a highly polymerized structure.

FIG. 4a is a graph showing samples prepared in example 1 and comparative examples 1 to 2¹³C solid nuclear magnetic resonance (¹³C NMR) carbon spectrum of example 1, comparative example 1 and comparative example 2 from the top to the bottom as shown in FIG. 4a¹³C solid nuclear magnetic resonance (¹³CNMR) carbon spectrum. Fig. 4a shows that the samples prepared in example 1 and comparative example 1 are carbon nitrogen polymers based on a triazine structure and chemical shift migration indicates that oxygen is incorporated in the structure, and the sample prepared in comparative example 2 is a highly polymerized carbon nitrogen polymer based on a heptazine structure.

FIG. 5a is an IR spectrum of samples prepared in example 1, comparative example 1 and comparative example 2, and as shown in FIG. 5a, IR spectra of example 1, comparative example 1 and comparative example 2 are shown from top to bottom. Fig. 5a shows that the samples prepared in example 1 and comparative example 1 are oxygen-doped carbon-nitrogen polymers and the sample prepared in comparative example 2 is a highly polymerized carbon-nitride polymer without a significant oxygen structure.

Fig. 7 is a comparison of the photocatalytic activities of example 1 and comparative examples 1 and 2, and as shown in fig. 7, example 1 has the strongest photocatalytic activity.

Example 2

The calcination time was changed to 2 hours, and the rest of the preparation process was the same as in example 1.

FIG. 1b is an X-ray diffraction (XRD) pattern of the samples prepared in examples 1-3, as shown in FIG. 1b, showing that the diffraction peak of the sample prepared in example 2 is similar to that of melem, indicating that the sample is an oligomeric carbon nitrogen photocatalyst.

FIG. 2f is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 2, as shown in FIG. 2f, which shows that the sample prepared in example 2 is a material with a rod structure grown on a lamellar structure, but the rod length is shorter, about 5 μm.

The IR spectroscopy in FIG. 5b shows that the sample prepared in example 2 also incorporates carbon-oxygen bonds.

FIG. 6b is a graph showing the UV-VIS absorption spectra of the samples prepared in examples 1-3, as shown in FIG. 6b, which shows that the sample prepared in example 2 has a low absorption intensity.

Fig. 8 shows that the sample prepared in example 2 has a certain photocatalytic activity.

Example 3

The calcination time was changed to 6 hours and the procedure was the same as in example 1.

Figure 1 bX-ray diffraction (XRD) pattern shows that the sample prepared in example 3 is an oligomeric carbon nitrogen material.

FIG. 2g is a Scanning Electron Microscope (SEM) photograph of the sample prepared in example 3, as shown in FIG. 2g, indicating that the sample prepared in example 3 has a rod-like structure.

FIG. 5b is an infrared spectrum analysis of a sample prepared in example 3, which shows that the incorporation of carbon-oxygen bonds increases oxygen defects and improves catalytic activity.

FIG. 6b UV-VIS absorption spectrum shows that the absorption intensity of the sample prepared in example 3 is strong.

Fig. 8 shows that the sample prepared in this example 3 has a certain photocatalytic activity.

FIG. 1b is an X-ray diffraction (XRD) pattern of the samples prepared in examples 1 to 3, and as shown in FIG. 1b, X-ray diffraction (XRD) patterns of the samples prepared in examples 1, 2 and 3 are sequentially from top to bottom, showing that diffraction peaks of the samples prepared in examples 1 to 3 are similar to those of melem, and it is explained that all the samples prepared in examples 1 to 3 are carbon-nitrogen oligomers.

FIG. 5b is an IR spectrum of the samples prepared in examples 1 to 3, and as shown in FIG. 5b, the IR spectra of the samples prepared in examples 1, 2 and 3 are shown from top to bottom, which indicates that the structures of the samples prepared in examples 1 to 3 all incorporate carbon-oxygen bonds.

FIG. 6b is an ultraviolet-visible absorption spectrum of the sample prepared in examples 1-3, which shows that the light absorption intensity of example 2 is low, and thus the corresponding photocatalytic activity is weak.

FIG. 8 is a comparison of the photocatalytic activities of examples 1 to 3, which shows that example 1 has the best photocatalytic activity compared with examples 2 to 3.

Example 4

The calcination temperature was changed to 400 ℃, the other preparation processes were the same as in example 1, and fig. 9 shows that the sample prepared in this example 4 has a certain photocatalytic activity.

Example 5

The calcination temperature was changed to 500 ℃, the other preparation processes were the same as in example 1, and fig. 9 shows that the sample prepared in this example 5 has a certain photocatalytic activity.

FIG. 9 is a comparison of the photocatalytic activities of examples 1, 4, and 5, showing that example 1 has the best photocatalytic activity compared to examples 4-5.

Example 6

The amount of water added was changed to 10mL, the rest of the preparation process was the same as in example 1, and fig. 5c is an infrared spectroscopic analysis of the samples prepared in examples 6 to 8, as shown in fig. 5c, indicating that a carbon-oxygen bond exists in the structure of the sample prepared in example 6; fig. 10 shows that the sample prepared in this example 6 has a certain photocatalytic activity.

Example 7

The water addition amount was changed to 20mL, the rest of the preparation process was the same as in example 1, and the IR spectrum analysis chart in FIG. 5c shows that the structure of the sample prepared in example 7 has a carbon-oxygen bond; fig. 10 shows that the sample prepared in example 7 has a certain photocatalytic activity.

Example 8

The water addition amount was changed to 40mL, the rest of the preparation process was the same as in example 1, and the IR spectrum analysis chart in FIG. 5c shows that the structure of the sample prepared in example 8 has a carbon-oxygen bond; fig. 10 shows that example 8 has similar photocatalytic activity to example 1.

FIG. 5c is an IR spectrum of samples prepared in examples 6-8, showing the presence of carbon-oxygen bonds in the structures of the samples prepared in examples 6-8.

FIG. 10 is a comparison of the photocatalytic activities of examples 1 and 6 to 8, which shows that example 1 has the best photocatalytic activity compared with examples 6 to 8.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. An oxazinyl carbon nitrogen polymer characterized by:

the heptazine-triazine-based carbon nitrogen polymer with a rod-shaped structure is formed by spontaneous oriented growth of a heptazine-based carbon nitrogen polymer with a lamellar structure.

2. An oxazinyl carbon nitrogen polymer according to claim 1, wherein:

the thickness of the heptazine-based carbon-nitrogen polymer of the lamellar structure is 5-15 microns, and the carbon-nitrogen ratio is 0.67;

the length of the heptazine-triazine carbon nitrogen polymer with the rod-shaped structure is 10-20 micrometers, and the diameter of the heptazine-triazine carbon nitrogen polymer is 50-75 nanometers.

3. An oxazinyl carbon nitrogen polymer according to claim 1 or 2, characterized in that:

the heptazine-based carbon nitrogen polymer of the lamellar structure is 10 microns thick;

the length of the heptazine-triazine carbon nitrogen polymer with the rod-shaped structure is 12-16 micrometers, and the diameter of the heptazine-triazine carbon nitrogen polymer is 55 nanometers.

4. A method of producing an oxazinyl carbon nitrogen polymer according to any one of claims 1 to 3, comprising:

step 1: fully dissolving melamine and water to obtain suspension;

step 2: roasting the suspension to obtain solid particles;

and step 3: cooling the solid particles to room temperature and grinding to obtain an azinyl carbon nitrogen polymer;

in the step 1, the feeding mass ratio of melamine to water is 3: 2-8; the dissolving temperature of melamine and water is 15-75 ℃; the dissolving time of the melamine and the water is 10-50 minutes;

in the step 2, the roasting temperature of the suspension is 400-500 ℃; the roasting time of the suspension is 2-6 hours; and the heating rate of the suspension liquid roasting is 3-8 ℃/min.

5. The method of producing an oxazinyl carbon nitrogen polymer of claim 4, further comprising:

in the step 1, the feeding mass ratio of melamine to water is 1: 2; the dissolving temperature of the melamine and the water is 25 ℃; the dissolution time of melamine with water was 30 minutes.

6. The method of producing an oxazinyl carbon nitrogen polymer of claim 4, further comprising:

in the step 2, the roasting temperature of the suspension is 450 ℃; the roasting time of the suspension is 4 hours; the heating rate of the suspension liquid roasting is 5 ℃/min.

7. Use of the azinyl carbon nitrogen polymer according to claim 1, characterized in that:

the oxazinyl carbon nitrogen polymer has photocatalytic activity in a visible light wave band, and can be used as a photocatalyst for photocatalytic sterilization.