Edible fungus residue carbon nanomaterial as well as preparation method and application thereof

Abstract

The invention discloses an edible fungus residue carbon nanomaterial as well as a preparation method and application thereof, and aims to provide a material which has high activity and high stability, can be used for detecting and identifying phenols in a water body in combination with reagents such as 4-AAP, TMB and the like in an extremely small dosage, and is used for detecting phenolic pollutants. The material is prepared by the following method: (1) heating mushroom dreg powder to 250-300 DEG C, keeping the temperature for 2-3 hours, and grinding the mushroom dreg powder into powder after the reaction is finished to obtain pre-carbonized product powder; (2) adding water into the pre-carbonized product powder and NaOH for dissolving, stirring at 60-80 DEG C to obtain gel, and drying to obtain powder; (3) heating the powder to 700-800 DEG C, keeping the temperature for 1-3 hours, and after the reaction is finished, grinding the powder into powder by using a mortar to obtain crude biochar; (4) carrying out acid pickling and water washing on the crude biochar until the crude biochar is neutral, and grinding to obtain activated biochar powder; (6) adding ethanol into the activated charcoal powder for dissolving; and then carrying out hydrothermal treatment at 160-200 DEG C for 16-18 hours, cooling, then sequentially carrying out centrifugation and suction filtration, collecting filter residues, and carrying out centrifugal drying, thereby obtaining the product. Belongs to the technical field of compound detection.

Description

Technical Field

[0001] The present invention relates to the technical field of detection, and particularly to an edible mushroom residue carbon nanomaterial. The present invention also relates to a preparation method of the edible mushroom residue carbon nanomaterial and its application in the detection of phenolic compounds. Background Art

[0002] With the progress of technology and the development of society, people's quality of life has been gradually improved, and food safety issues have gradually come into the public eye. Endogenous and exogenous pollution in food is harming people's health. Among them, phenolic pollutants, as one of the most harmful pollutants to the human body among exogenous pollutants, are gradually coming into the public view.

[0003] Phenolic pollutants are widely used in the production of industry and agriculture. Due to improper treatment and discharge, it is extremely easy to pollute surface water, and accumulate through the food chain, ultimately endangering the health of animals and humans. Most of the drinking water in life uses surface water as raw water and is obtained through purification. Therefore, the detection of phenolic pollutants in water is of crucial significance.

[0004] At present, the methods for detecting phenols mainly include chromatography and electroanalysis. Although these methods can detect phenols well, there are still some drawbacks hindering their development in some fields. Chromatographic analysis has the advantages of fast analysis speed, high detection sensitivity, and good selectivity. However, the analysis process takes a relatively long time, and for problems such as complex sample matrix and too low sample concentration, chromatographic analysis cannot accurately analyze them; Electrochemical analysis has the advantages of wide measurement range, high stability, good reproducibility, and high accuracy. However, in the process of detecting phenolic compounds by electrochemical methods, there is often a problem of poor selectivity, and it can only detect the content of total phenols, and cannot achieve the detection of single phenolic pollutants.

[0005] To overcome the above limitations, a colorimetric sensor array will be a new strategy to solve the above problems: on the one hand, analytes with similar structures and properties in the sensor array can generate their respective unique response patterns through different reactions, and then further use multivariate statistical analysis methods to achieve high-throughput detection and identification of multiple targets; on the other hand, the colorimetric sensor array is relatively simple and flexible to operate, can avoid using heavy and expensive instruments, and greatly saves the detection cost. These advantages make it a portable tool for on-site analysis.

[0006] Nanozymes (abbreviated as nanozymes, Nanozyme) are a class of nanomaterials with enzyme-like catalytic properties, which have attracted extensive attention due to their high stability and low cost compared with natural enzymes. At present, a large number of experiments have shown that the size and morphology of nanomaterials have a certain impact on the catalytic activity of the reaction system. When the size of a specific substance is reduced to the nanoscale, its surface area increases greatly, which helps to increase the active sites on the surface and improve its catalytic activity.

[0007] In the past few decades, carbon nanomaterials have received extensive attention. They have a variety of structures, such as three-dimensional diamond and graphene foams, two-dimensional graphene and graphyne, one-dimensional carbon nanotubes (CNTs), and zero-dimensional fullerenes and carbon quantum dots. Carbon nanomaterials have the following advantages: (1) They have high strength and high toughness and can be used to prepare high-strength and lightweight materials; (2) They have good thermal stability and can be applied to high-temperature environments, refractory fields, etc.; (3) They have excellent electrical properties and have great potential in the fields of electronic devices and materials; (4) They have good biocompatibility and can be applied to biosensors and drug delivery, etc. Because of these advantages, carbon nanomaterials have broad application prospects in catalysis, energy storage and conversion, environmental science, and biomedicine. Due to their good surface characteristics and wide adaptability, carbon nanomaterials have attracted much attention and have become a new type of inorganic and organic pollutant detection material.

[0008] The carbon nanomaterials / carbon nanoparticles used in this experiment are prepared from materials such as crop residues and waste biomass. First, the raw material edible mushroom residue is processed into catalytically active edible mushroom residue biochar by alkali activation and high-temperature co-thermal carbonization method. Then, the relatively large biochar is transformed into relatively fine carbon nanomaterials through hydrothermal and centrifugal ultrasonic methods. At the same time, its surface morphology and properties also change to a certain extent. After experimental verification, it has great application prospects in the detection of organic pollutants, and also has better surface activity and catalytic activity. It is a nanozyme material with broad application prospects. Summary of the Invention

[0009] Aiming at the deficiencies of the existing technology, the present invention provides a preparation method of edible mushroom residue carbon nanomaterials. Specifically, taking edible mushroom residue as a carbon source and a nitrogen source, activated edible mushroom residue biochar is obtained by high-temperature co-thermal carbonization, and then the biochar is further processed into carbon nanomaterials through hydrothermal and centrifugal drying methods. This preparation method is simple to operate and low in cost.

[0010] The second object of the present invention is to provide an edible mushroom residue carbon nanomaterial, which can detect and identify phenols in water with a very small amount (1-5 mg) in combination with reagents such as 4-AAP and TMB. Due to its advantages of high activity, high stability and low cost, during the detection process, phenolic pollutants can directly or indirectly interact with it, change its catalytic activity, and cause the color of the reaction system to change, so as to achieve the purpose of detecting phenolic pollutants.

[0011] The last object of the present invention is to provide the application of the above-mentioned edible mushroom residue carbon nanomaterial in detecting phenols in water under the conditions of 4-AAP and TMB.

[0012] To achieve the above object, the present invention provides the following technical solutions:

[0013] A preparation method of an edible mushroom residue carbon nanomaterial successively includes the following steps:

[0014] (1) Wash, dry and crush the edible mushroom residue to obtain mushroom residue powder;

[0015] (2) Transfer the mushroom residue powder in step (1) to a calcination dish of a tube furnace after drying, and then transfer it to the tube furnace. In a nitrogen atmosphere, heat it to 200-300 °C and keep it for 1-3 h. After the reaction is completed, cool it to room temperature under nitrogen protection to obtain a pre-carbonized product and grind it into powder with a mortar to obtain pre-carbonized product powder;

[0016] (3) Weigh the pre-carbonized product powder prepared in step (2) and NaOH according to a mass ratio of 1:5-7, add water to dissolve it, and then continue to stir vigorously at 70-90 °C until it becomes gel-like and dry it for standby;

[0017] (4) Transfer the powder in (3) to a calcination dish of a tube furnace, and then transfer it to the tube furnace. Heat it to 700-900 °C in a nitrogen atmosphere and keep it at a constant temperature for 1-3 h. After the reaction is completed, cool it to room temperature under nitrogen protection to obtain a high-temperature carbonized product and grind it into powder with a mortar to obtain crude biochar;

[0018] (5) Acid-wash the crude biochar obtained in (4), then wash it with ionized water until it is neutral and grind it into activated biochar powder;

[0019] (6) Add an ethanol solution to the activated biochar powder prepared in step (5) and stir well to dissolve it; then transfer it to a reaction kettle, carry out hydrothermal treatment at 160-200 °C for 16-18 h, take it out after cooling, carry out centrifugation and suction filtration in sequence, collect the filter residue, and dry it by centrifugation to obtain the mushroom residue carbon nanomaterial.

[0020] Further, in the preparation method of the edible mushroom residue carbon nanomaterial described above, the heating rate in step (2) is 10 ± 1 °C / min; the heating rate in step (4) is 5 ± 1 °C / min.

[0021] Further, in the preparation method of the activated edible mushroom residue biochar described above, the amount of added dewatered water during dissolution in step (3) is 4 - 5 times the total mass of the pre-carbonized product powder and NaOH.

[0022] Further, in the preparation method of the edible mushroom residue carbon nanomaterial described above, the pickling in step (5) is to fully wash with 2 - 4M hydrochloric acid for 6 - 12 h.

[0023] Further, in the preparation method of the edible mushroom residue carbon nanomaterial described above, the ethanol solution in step (6) is composed of anhydrous ethanol and deionized water mixed in a volume ratio of 1:1.

[0024] Further, in the preparation method of the activated edible mushroom residue carbon nanomaterial described above, the centrifugation speed in step (6) is 8000 rpm / min, and the centrifugation time is 10 - 30 min; the filter membrane used for suction filtration is 0.22 μm; the drying time of the filter residue is 24 h.

[0025] The second technical solution of the present invention provides an edible mushroom residue carbon nanomaterial prepared by the method described in the first technical solution.

[0026] Another technical solution of the present invention is to provide the application of the above-mentioned edible mushroom residue carbon nanomaterial in detecting and identifying phenolic compounds in water.

[0027] Another technical solution of the present invention is to provide a colorimetric sensor array. Using the edible mushroom residue carbon nanomaterial described in the second technical solution as a catalyst, under non-illuminated conditions, the edible mushroom residue carbon nanomaterial described in claim 7 and a color developer are added to the water sample to be treated containing phenols, and left to stand until the reaction is completed. Record the color development result. At the same time, use a UV-visible spectrophotometer (UV-3600Plus) to measure the absorbance of each reaction group at the corresponding wavelength, and use Matlab and Originlab to draw a linear discriminant analysis (LDA) graph and a hierarchical clustering analysis (HCA) graph of the colorimetric results. Then, combined with the color development results obtained from the colorimetric plate, a 6-channel colorimetric sensor array is constructed (2 enzyme-mimicking activities × 3 time points = 6 sensing channels), and 6 kinds of phenols are identified and analyzed. According to the differences presented by the spectra and colorimetric results, the effect of quickly identifying and differentiating different phenolic compounds is achieved.

[0028] The color developer is one of 4-AAP and TMB.

[0029] Compared with the prior art, the technical solution provided by the present invention has the following technical advantages:

[0030] 1. The edible mushroom residue carbon nanomaterial provided by the present invention uses edible mushroom residue as the raw material, and obtains the edible mushroom residue carbon nanomaterial by means of high-temperature co-thermal carbonization and centrifugal drying. This preparation method is simple to operate and the material source is simple. Compared with metal catalysts, it has a high cost advantage. On the other hand, the raw material edible mushroom residue is widely sourced as agricultural waste, achieving the effect of turning waste into useful materials, and the operation process during the preparation of the modified biochar is simple and safe.

[0031] 2. When the edible mushroom residue carbon nanomaterial provided by the present invention is used to synthesize biochar at high temperature, various vacancies are left due to the overflow of heteroatoms, thus creating more microscopic defects, which is beneficial for the material to combine with the chromogenic substrate to exhibit its nanozyme activity. At the same time, under the catalytic action of the nanozyme, the chromogenic substrate can undergo oxidative coupling with phenolic compounds, thereby realizing the colorimetric detection of phenolic compounds. During the detection process, phenolic pollutants can directly or indirectly interact with the nanozyme, changing its catalytic activity and causing a change in the color of the reaction system, thus achieving the purpose of detecting phenolic pollutants.

[0032] 3. The method for preparing edible mushroom residue carbon quantum dots with peroxidase-like activity under high-temperature co-thermal carbonization and high-temperature hydrothermal conditions provided by the present invention and the application of this edible mushroom residue carbon nanomaterial are based on the promoting effect of carbon quantum dots on the oxidation of 4-AAP and TMB, and construct a nanozyme colorimetric sensor and a sensing detection principle for detecting various phenols. This nanozyme colorimetric sensing detection method has significant advantages such as high sensitivity, wide linear range, low cost, and easy operation. Description of the Drawings

[0033] Figure 1 Photograph of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention;

[0034] Figure 2 TEM image of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention;

[0035] Figure 3 XPS image of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention;

[0036] Figure 4 XRD image of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention;

[0037] Figure 5 UV-visible absorption spectra of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention in different reaction systems;

[0038] Figure 6 Graph of the change in absorbance of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention with time in the reaction system

[0039] Figure 7 Working curve diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP under different concentrations of p-chlorophenol;

[0040] Figure 8 Fingerprint spectrum of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP under different types of phenols;

[0041] Figure 9 Ultraviolet absorbance error spectrum diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP in different water bodies containing p-chlorophenol;

[0042] Figure 10 Response of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention in a colorimetric sensor to different substances;

[0043] Figure 11 LDA diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP and TMB under different phenols;

[0044] Figure 12 HCA diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP and TMB under different phenols;

[0045] Figure 13 LDA diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP and TMB under different types of substituted phenols;

[0046] Figure 14 HCA diagram of the carbon nanomaterial from edible mushroom residue prepared in the embodiment of the present invention and 4-AAP and TMB under different types of substituted phenols. Detailed implementation manners

[0047] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments and the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] The edible mushroom residue mentioned below refers to the edible mushrooms being Lentinula edodes and Auricularia auricula (mass ratio 1:1) as described therein.

[0049] Example 1

[0050] A carbon nanomaterial from edible mushroom residue provided by the present invention is prepared through the following steps:

[0051] (1) Pretreatment of the crude biochar of the mushroom residue

[0052] The edible mushroom residue is crushed and then repeatedly rinsed with deionized water and ethanol, and then dried. The dried sample is placed in a tubular furnace and heated to 300 °C at a rate of 10 °C / min and held at a constant temperature for 2 h. At the same time, nitrogen is introduced to ensure that the tube is filled with nitrogen. After cooling, the sample is taken out, ground into fine powder, and the soluble impurities of the material are repeatedly rinsed with deionized water and ethanol. Finally, the solid material is filtered out by suction and dried (60 - 80 °C, 12 h) to obtain the crude biochar of the mushroom residue;

[0053] (2) Activation treatment of the crude biochar of the mushroom residue

[0054] The crude biochar material of the mushroom residue after pre-carbonization is mixed with NaOH in a mass ratio of 1:6 and placed in a container. Deionized water 4 times the mass of the solid is added, and it is continuously stirred vigorously at 70 °C until a gel-like mucus is formed. Then it is placed in an oven and dried at 80 °C to obtain the activated biochar of the mushroom residue;

[0055] (3) Synthesis of the activated edible mushroom residue biochar

[0056] The activated biochar of the mushroom residue obtained in step (2) is evenly mixed by grinding, transferred to a special calcination dish for the tubular furnace, and then transferred to the tubular furnace. It is held at a constant temperature of 800 °C for 2 h. After cooling, it is taken out, washed thoroughly with 3M hydrochloric acid for 12 h, repeatedly washed with deionized water until neutral and filtered by suction, dried, and finally the biochar is ground to pass through a 200-mesh sieve. The obtained product is the activated edible mushroom residue biochar;

[0057] (4) Synthesis of the edible mushroom residue carbon nanomaterial

[0058] After the activated edible mushroom residue biochar powder obtained in step (3) is passed through a 100-mesh sieve, an ethanol solution 3 times the mass of the activated edible mushroom residue biochar powder (the ethanol solution is composed of deionized water and absolute ethanol with a volume ratio of 1:1) is added and mixed thoroughly to obtain a mixed product;

[0059] The treated mixed product is transferred to a reaction kettle, hydrothermally treated at 160 °C for 16 h, taken out after cooling to room temperature, centrifuged and filtered by suction in sequence, the filter residue is collected, centrifugally dried, the centrifugal speed is 10000 rpm / min, and the centrifugal time is 30 min; the filter membrane used for suction filtration is 0.22 μm; the drying time of the filter residue is 4 h, and the edible mushroom residue carbon nanomaterial (BC-NP S ) is obtained.

[0060] In order to verify the physicochemical properties of the edible mushroom residue carbon nanomaterial provided by this application, the following detection chromatograms of the edible mushroom residue carbon nanomaterial provided by the examples are given:

[0061] Refer to the photograph of the edible mushroom residue carbon nanomaterial Figure 1 , through Figure 1It can be seen that the carbon nanomaterial from edible mushroom residue is in the form of black powder, with extremely fine particles and a slightly black gloss on the surface.

[0062] Refer to the TEM image Figure 2 , through Figure 2 It can be seen that the carbon nanomaterial from edible mushroom residue has an obvious pore structure, is evenly dispersed, and there is no obvious agglomeration phenomenon. The gaps help increase the specific surface area of the material, thereby improving its adsorption performance and reaction activity, and providing a structural basis for its good adsorption performance. It can also be seen that the particle size distribution of the spherical solid particles is relatively uniform, indicating that the preparation method has good controllability and repeatability.

[0063] Refer to the XPS image Figure 3 , through Figure 3 It can be seen that the surface elements of the carbon nanomaterial from edible mushroom residue are mainly composed of C, N, and O, indicating that the material surface contains rich functional groups. These functional groups are beneficial to enhancing the catalytic activity of the material. Specifically, the C peak has the highest intensity, indicating that the content of carbon element in the sample is relatively high; the O peak intensity is the second, indicating that the oxygen element content is the second; the N peak intensity is the lowest, meaning that the content of nitrogen element in the sample is relatively small.

[0064] Refer to the XRD image Figure 4 , through Figure 4 It can be seen that a series of diffraction peaks appear in the XRD pattern of the carbon nanomaterial from edible mushroom residue. These diffraction peaks all belong to the face-centered cubic structure. Several obvious diffraction peaks can be seen in the figure, located at about 20°, 26°, 30°, 35°, 42°, etc. These angles correspond to the diffraction angles of different crystal planes, corresponding to the (111), (211), (220), (311), (400), etc. planes in the figure respectively; indicating that the carbon nanomaterial from edible mushroom residue has good crystallinity and its crystal structure is stable.

[0065] Example 2

[0066] A carbon nanomaterial from edible mushroom residue provided by the present invention is prepared through the following steps:

[0067] (1) Pretreatment of crude biochar from mushroom residue

[0068] After the edible mushroom residue is crushed, it is repeatedly rinsed with deionized water and ethanol and then dried. The dried sample is placed in a tube furnace, heated to 250°C at a rate of 10°C / min and kept at a constant temperature for 2 h. At the same time, nitrogen is introduced to ensure that the tube is filled with nitrogen. After cooling, the sample is taken out, ground into fine powder, and the soluble impurities of the material are repeatedly rinsed with deionized water and ethanol. Finally, the solid material is filtered out by suction and dried (60 - 80°C) to obtain crude biochar from mushroom residue.

[0069] (2) Activation treatment of crude mushroom residue biochar

[0070] After pre-carbonization, the crude mushroom residue biochar material is mixed with NaOH at a mass ratio of 1:8 and placed in a container. Deionized water 4 times the mass of the solid is added, and vigorous stirring is continued at 80 °C until a gel-like mucus is formed. Then it is placed in an oven and dried at 80 °C for later use.

[0071] (3) Synthesis of activated edible mushroom residue biochar

[0072] The activated mushroom residue biochar obtained in step (2) is ground and mixed evenly, transferred to a special calcination dish for a tube furnace, and then transferred to the tube furnace. It is reacted at a constant temperature of 700 °C for 2 h. After cooling, it is taken out, washed thoroughly with 3M hydrochloric acid for 12 h, repeatedly washed with deionized water until neutral and filtered by suction, dried, and finally the biochar is ground to pass through a 200-mesh sieve. The obtained product is the activated edible mushroom residue biochar.

[0073] (4) Synthesis of edible mushroom residue carbon nanomaterials

[0074] The activated edible mushroom residue biochar powder obtained in step (3) is passed through a 100-mesh sieve, and deionized water and absolute ethanol are added in a 1:1 ratio and mixed thoroughly. The amount of deionized water and absolute ethanol added during mixing is 4 times the total mass of the mixture;

[0075] The treated mixed product is transferred to a reaction kettle, hydrothermally treated at 200 °C for 16 h, taken out after cooling to room temperature, centrifuged and filtered by suction in turn, the filter residue is collected, centrifugally dried, the centrifugal speed is 10000 rpm / min, and the centrifugal time is 30 min; the filter membrane used for suction filtration is 0.22 μm; the drying time of the filter residue is 4 h, and the edible mushroom residue carbon nanomaterials are obtained.

[0076] Example 3

[0077] A preparation method of edible mushroom residue carbon nanomaterials provided by the present invention, the preparation steps are as follows:

[0078] (1) Pretreatment of crude mushroom residue biochar

[0079] The edible mushroom residue is crushed and repeatedly rinsed with deionized water and ethanol in turn and then dried. The dried sample is placed in a tube furnace, heated to 250 °C at a rate of 10 °C / min and kept at a constant temperature for 3 h. At the same time, nitrogen is introduced to ensure that the inside of the tube is filled with nitrogen. After cooling, the sample is taken out, ground into fine powder, and the soluble impurities of the material are repeatedly rinsed with deionized water and ethanol. Finally, the solid material is filtered by suction and dried (60-80 °C) to obtain the crude mushroom residue biochar.

[0080] (2) Activation treatment of crude mushroom residue biochar

[0081] The pre-carbonized crude biochar material of mushroom residue and NaOH are mixed in a mass ratio of 1:8 and placed in a container. Deionized water with a volume 5 times the mass of the solid is added, and the mixture is continuously stirred vigorously at 80 °C until a gel-like mucus is formed. Then it is placed in an oven and dried at 80 °C for later use.

[0082] (3) Synthesis of activated mushroom residue biochar

[0083] The activated mushroom residue biochar obtained in step (2) is ground and mixed evenly, transferred to a special calcination dish for a tube furnace, and then transferred to the tube furnace. It is reacted at a constant temperature of 700 °C for 3 h, taken out after cooling, washed thoroughly with 3M hydrochloric acid for 12 h, repeatedly washed with deionized water until neutral and then filtered by suction, dried, and finally the biochar is ground to pass through a 200-mesh sieve. The obtained product is the activated mushroom residue biochar.

[0084] (4) Synthesis of mushroom residue carbon nanomaterials

[0085] The activated mushroom residue biochar powder obtained in step (3) is passed through a 100-mesh sieve, and deionized water and absolute ethanol are added in a ratio of 1:1 and mixed thoroughly. The amount of deionized water and absolute ethanol added during mixing is 4 times the total mass of the mixture.

[0086] The treated mixed product is transferred to a reaction kettle, hydrothermally treated at 200 °C for 18 h, taken out after cooling to room temperature, centrifuged and filtered by suction in sequence. The filter residue is collected, centrifugally dried. The centrifugation speed is 10000 rpm / min and the centrifugation time is 30 min; the filter membrane used for suction filtration is 0.22 μm; the drying time of the filter residue is 4 h, and the mushroom residue carbon nanomaterials are obtained.

[0087] The following gives specific application examples of the mushroom residue carbon nanomaterial composite non-metallic catalyst provided by this application:

[0088] The carbon nanomaterial suspension described in the following application examples is composed of carbon nanomaterials and deionized water. The ratio of the carbon nanomaterials to deionized water is 0.5 mg: 1 mL. The carbon nanomaterials are dispersed in deionized water for subsequent reactions.

[0089] Application Example 1 Research on the catalytic activity of mushroom residue carbon nanomaterials

[0090] The specific experimental method is as follows: 1) Take 1 mL of sodium acetate - acetic acid (NaAc - HAc) buffer solution (0.2 M, pH 4.0), and successively add 900 μL of 4 - aminoantipyrine (4 - AAP) (8 mM), 900 μL of 4 - chlorophenol (4 - CP, 4 mM), 100 μL of the carbon nanomaterial suspension prepared in Example 1, and 100 μL of hydrogen peroxide (H 2 O 2)(10 mM) to obtain the experimental group mixture (BC-NP S +H 2 O 2 + 4-CP + 4-AAP); the control group does not contain the carbon nanomaterial prepared in Example 1, and the other substances and their contents remain unchanged, denoted as the control group 1 mixture (H 2 O 2 + 4-CP + 4-AAP); the control group 2 does not contain hydrogen peroxide (H 2 O 2 ), and the other substances and their contents remain unchanged, denoted as the control group 2 mixture (BC-NP S + 4-CP + 4-AAP); after the above mixed solutions are reacted at room temperature for 30 minutes respectively, the absorbance values of the reaction systems at 515 nm are detected by a UV-visible spectrophotometer.

[0091] 2) Take 1 mL of sodium acetate - acetic acid (NaAc-HAc) buffer solution (0.2 M, pH 4.0), and sequentially add 900 μL of 4-aminoantipyrine (4-AAP) (8 mM), 900 μL of p-chlorophenol (4 mM), and 100 μL of the carbon nanomaterial suspension prepared in Example 1 to the solution. After the above mixed solution is reacted at room temperature for 30 minutes, the absorbance value of the reaction system at 515 nm is detected by a UV-visible spectrophotometer.

[0092] The results are as Figure 5 , Figure 6 shown. It can be seen from Figure 5 that when there is no H 2 O 2 in the solution, the absorption peak at 515 nm in the UV-visible absorption spectrum does not change significantly. When there is no carbon nanomaterial in the solution, the intensity of the absorption peak at 515 nm in the UV-visible absorption spectrum slightly increases. This change is mainly attributed to the fact that in the presence of a higher concentration of H 2 O 2 , it can promote the interaction between phenol and 4-AAP and cause its oxidation, resulting in a change in the color of the solution. When there are carbon nanomaterials, 4-AAP, and H2O2 in the solution at the same time, an obvious absorption peak appears at 515 nm in the UV-visible absorption spectrum. This phenomenon indicates that the carbon nanomaterial indeed has the catalytic effect of peroxidase and can catalyze the decomposition of H 2 O 2 , promoting the oxidative coupling of p-chlorophenol and 4-AAP to produce a red product. It can be seen from the change of the absorbance value at 515 nm with time in Figure 6 that with the change of time, carbon nanomaterials + H 2 O 2The absorbance value of the reaction system of p-chlorophenol + 4-AAP continuously increases, indicating that the carbon nanomaterial has good peroxidase catalytic activity.

[0093] Application Example 2 Quantitative Detection of Phenols by Carbon Nanomaterials from Edible Mushroom Residue

[0094] Take 1.15 mL of NaAc-HAc buffer solution (0.2 M, pH 4.0), and successively add 750 μL of 4-AAP (4-aminoantipyrine) (8 mM), 100 μL of H 2 O 2 (1 M), 100 μL of the carbon nanomaterial suspension prepared in Example 1, and 900 μL of phenol at different concentrations (5 nM, 6 nM, 7 nM, 8 nM, 9 nM, 10 nM, 11 nM, 12 nM, 13 nM, 14 nM, 15 nM, 16 nM). After reacting the above mixed solution at room temperature for 30 minutes, measure the reaction system with a UV-visible spectrophotometer, record and analyze the experimental results. The results are as Figure 7 shown. Through Figure 7 it can be seen that y = 0.27089 + 0.00533; R 2 = 0.96569, A 515 and the concentration of p-chlorophenol show a good linear relationship with the absorbance value in the range of 5 mM - 16 mM. The linear correlation coefficient is 0.96569, and the corresponding fitting equation is A 515 = 0.27089 [p-chlorophenol] (mM) + 0.00533; proving that this method has good reproducibility and accuracy.

[0095] Application Example 3 Study on the Effect of Phenolic Pollutants on the Activity of Carbon Nanomaterials from Edible Mushroom Residue

[0096] The specific experimental method is as follows: Take 1.15 mL of NaAc-HAc (pH 4.0) buffer solution, and successively add 100 μL of the carbon nanomaterial suspension prepared in Example 2, 100 μL of H 2 O 2 (1 M), and 750 μL of 4-AAP (8 mM). After mixing the above solution evenly, add 900 μL of 4 mM phenol, p-chlorophenol (4-CP), p-nitrophenol (4-NP), p-aminophenol (4-AP), 2,4-dichlorophenol (2,4-2CP), and hydroquinone. Immediately measure the mixed solution with a UV-visible spectrophotometer, record the absorbance value at 515 nm after 30 minutes, and conduct 6 repeated experiments, recording a total of 36 groups of data.

[0097] The results are shown in Figure 8 , through Figure 8 it can be seen that, throughFigure 8 It can be seen that compared with phenol, the absorbance value of 4-AP at 515 nm increases significantly, indicating that 4-AP plays a positive promoting role in the color change of the system, while 4-CP and 4-NP inhibit the reaction system to varying degrees. This phenomenon is mainly caused by the substituent effect. Compared with phenol, the newly introduced substituents (-Cl, -NH 2 and -NO 2 ) will have a certain impact on the original substituent (-OH) on the benzene ring and further lead to changes in the reactivity of the analyte.

[0098] Detection effect in actual water bodies of Application Example 4

[0099] To verify the detection effect of this material in actual water bodies, different water bodies containing 4-chlorophenol were selected (deionized water

[0100] tap water, Lake Water 1 (from the inner lake of the school), Lake Water 2 (from the central lake of the university town), River Water 1 (from the outer river of the university town)) for experiments.

[0101] The specific experimental method is as follows: Prepare 4-chlorophenol solutions with a concentration of 4 mM from the above 5 water samples. Take 900 μL of the 4-chlorophenol solution containing each water sample (4 mM) and place it in different centrifuge tubes. Then add 1.15 mL of NaAc-HAc buffer solution (0.2 M, pH 4.0) to each centrifuge tube, and add 750 μL of 4-AAP (8 mM), 100 μL of the suspension of the carbon nanomaterial prepared in Example 2 (the suspension of the carbon nanomaterial is composed of the carbon nanomaterial and deionized water, and the ratio of the carbon nanomaterial to deionized water is 0.5 mg: 1 mL) and 100 μL of H 2 O 2 (1 M). After reacting the above mixed solution at room temperature for 30 minutes, use a UV-visible spectrophotometer to detect the absorbance value of the reaction system at 515 nm.

[0102] The experimental results are shown in Figure 9 , and it can be seen through Figure 9 that the carbon nanomaterial prepared from edible mushroom residues in Example 1 shows good stability and accuracy in different water bodies, and the UV absorbance error is small, indicating that the system can achieve almost the same detection effect regardless of the type of water body when detecting 4-chlorophenol.

[0103] Application Example 5

[0104] Response of the carbon nanomaterial prepared from edible mushroom residues in the embodiments of the present invention to different substances in the colorimetric sensor

[0105] The specific experimental method is as follows: Prepare p-chlorophenol solution (4 mM), phenol solution (4 mM), ethanol solution (4 mM), acetone solution (4 mM), cyclohexane solution (4 mM) and 1-methylimidazole solution (4 mM) with deionized water respectively. Take 900 μL and place them in different centrifuge tubes. Then add 1.15 mL of NaAc-HAc buffer solution (0.2 M, pH 4.0), 750 μL of 4-AAP (8 mM) and 100 μL of carbon nanomaterial suspension into each centrifuge tube. After reacting the above mixed solution at room temperature for 30 minutes, use a UV-visible spectrophotometer to detect the absorbance value of the reaction system at 515 nm.

[0106] Through Figure 10 It can be seen that the results show that only p-chlorophenol and phenol exist in the carbon nanomaterial + 4-AAP + H 2 O 2 reaction system, which will significantly enhance the absorbance value. In addition, the presence of cyclohexane will also cause a relatively obvious change in the absorbance value. The addition of other substances does not cause an obvious change in the reaction system, indicating that the influence of these substances on the detection of phenols can be ignored, indicating that this phenol detection colorimetric sensor has good anti-interference performance.

[0107] Application Example 6 Colorimetric Sensor Array

[0108] The preparation method of the colorimetric sensor based on carbon nanomaterials is as follows: First, add 100 μL of carbon nanomaterial suspension, 100 μL of H 2 O 2 (1 M) and 750 μL of 4-AAP (8 mM) to 1.15 mL of NaAc-HAc (pH 4.0) buffer solution for mixing, and then add 900 μL of 6 phenolic pollutants with different concentrations (phenol, 4-CP, 4-NP, 4-AP, 2,4-2CP and hydroquinone) to the above solution. After incubating at room temperature for 30 min, use a UV-visible spectrophotometer to measure the reaction system, and record the absorbance value at 515 nm for identifying 6 phenolic pollutants.

[0109] Then add 100 μL of carbon nanomaterial suspension (the carbon nanomaterial suspension is composed of carbon nanomaterials and deionized water, and the ratio of the carbon nanomaterials to deionized water is 0.5 mg: 1 mL), 25 μL of H 2 O 2(1 M) and 25 μL TMB (5 mM in DMSO) were added to 1.15 mL of NaAc-HAc (pH 4.0) buffer solution for mixing, and then 900 μL of 6 phenolic pollutants with different concentrations (phenol, 4-CP, 4-NP, 4-AP, 2,4-2CP, and hydroquinone) were added to the above solution. The obtained original data was converted into a training matrix, and linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA) were used for calculation and analysis, and a two-dimensional score plot was output on OriginLab. The analysis results are as Figures 11 - 14 shown.

[0110] The LDA diagram of the edible mushroom residue carbon nanomaterial prepared in Example 1 of the present invention with 4-AAP and TMB under different phenols is referred to Figure 11 , and through Figure 11 it can be seen that each phenolic compound was completely divided into 6 independent clusters without overlap with each other, proving that the sensor array can be well used to distinguish different phenolic compounds.

[0111] The HCA diagram of the edible mushroom residue carbon nanomaterial prepared in the embodiment of the present invention with 4-AAP and TMB under different phenols is referred to Figure 12 , and through Figure 12 it can be seen that the six phenolic compounds can be roughly divided into three different clusters: hydroquinone is a cluster, and such analytes can quickly react with the chromogenic substrates 4-AAP and TMB under the catalysis of the edible mushroom residue carbon nanomaterial; phenol, 4-CP, 4-NP, and 2,4-2CP belong to the same cluster, and the reaction process of such analytes is relatively mild; 4-AP forms a separate cluster, which can inhibit the catalytic activity of the edible mushroom residue carbon nanomaterial, resulting in a relatively slow reaction process and an unclear color change.

[0112] The LDA diagram of the edible mushroom residue carbon nanomaterial prepared in the embodiment of the present invention with 4-AAP and TMB under different substituents of phenolic compounds is referred to Figure 13 , and through Figure 13 it can be seen that each phenolic compound was completely divided into 6 independent clusters without overlap with each other, proving that the sensor array can be well used to distinguish phenolic compounds with different substituents.

[0113] The HCA diagram of the edible mushroom residue carbon nanomaterial prepared in the embodiment of the present invention with 4-AAP and TMB under different substituents of phenolic compounds is referred to Figure 14 , and through Figure 14It can be seen that the six phenolic compounds can be roughly divided into three different clusters: 2-CP forms one cluster, which can rapidly react with the chromogenic substrates 4-AAP and TMB under the catalysis of carbon nanomaterials from edible mushroom residues; 3-CP, 4-CP, 2-NP, and 3-NP belong to the same cluster, and the reaction process of these analytes is relatively mild; 4-NP forms a separate cluster, which can inhibit the catalytic activity of carbon nanomaterials from edible mushroom residues, resulting in a relatively slow reaction process and an insignificant color change.

Claims

1. A method for preparing edible mushroom residue carbon nanomaterials, characterized in that: The steps are as follows: (1) washing, drying and crushing edible mushroom residue to obtain mushroom residue powder; (2) drying the slag powder in step (1) and transferring it to a tubular furnace calcining dish, and then transferring it to a tubular furnace, heating it to 250-300° C. in a nitrogen atmosphere and maintaining it for 2-3 hours. After the reaction is completed, cooling it to room temperature under nitrogen protection to obtain a pre-carbonized product, and grinding it into powder with a mortar to obtain a pre-carbonized product powder; (3) Weigh the pre-carbonized product powder prepared in step (2) and NaOH in a mass ratio of 1:6-8, add water to dissolve, continue to vigorously stir at 60-80°C until it becomes a gel-like state, and dry it into powder; (4) The powder prepared in step (3) is transferred to a calcining dish of a tubular furnace, and then transferred to a tubular furnace, and heated to 700-800° C. in a nitrogen atmosphere and kept at a constant temperature for 1-3 hours. After the reaction is completed, the powder is cooled to room temperature under nitrogen protection to obtain a high-temperature carbonized product, which is then ground into powder with a mortar to obtain crude biochar; (5) washing the crude biochar prepared in step (4) with acid, then washing with ionized water until neutral, and grinding to obtain activated biochar powder; (6) Add ethanol solution to the activated biochar powder prepared in step (5), and stir thoroughly to mix and dissolve; then transfer to a reactor, hydrothermally heat at 160-200° C. for 16-18 h, take out after cooling, centrifuge and filter in sequence, collect the filter residue, and centrifuge and dry to obtain the biochar residue carbon nanomaterial.

2. The method for preparing edible fungus residue carbon nanomaterial according to claim 1, characterized in that: The heating rate of step (2) is 10±1°C / min; the heating rate of step (4) is 5±1°C / min.

3. The method for preparing activated edible fungus residue biochar according to claim 1, characterized in that: During the dissolution in step (3), water is added in an amount of 3 to 4 times the total mass of the pre-carbonized product powder and NaOH.

4. The method for preparing edible fungus residue carbon nanomaterial according to claim 1, characterized in that: The acid washing in step (5) is performed by using 2-4M hydrochloric acid for 6-12 hours.

5. The method for preparing edible fungus residue carbon nanomaterial according to claim 1, characterized in that: The ethanol solution described in step (6) is prepared by mixing anhydrous ethanol and deionized water in a volume ratio of 1:

1.

6. The method for preparing activated edible fungus residue carbon nanomaterial according to claim 1, characterized in that: In step (6), the centrifugal speed is 8000 rpm / min, the centrifugal time is 10-30 min, the filter membrane used for filtration is 0.22 μm, and the filter residue is dried for 24 h.

7. An edible mushroom residue carbon nanomaterial, characterized in that: Prepared by the method described in any one of claims 1 to 6.

8. Use of the edible fungus residue carbon nanomaterial according to claim 7 in detecting and identifying phenolic compounds in water.

9. A colorimetric sensor array, characterized in that: The activated edible mushroom residue carbon nanomaterial described in claim 7 is used as a catalyst. Under non-light conditions, the edible mushroom residue carbon nanomaterial described in claim 7 and a color developer are added to a water sample to be treated containing phenols, and the sample is allowed to stand for the reaction to be completed. The color development result is recorded, and an ultraviolet spectrophotometer is used to measure the absorbance of each reaction group at the corresponding wavelength. A linear discriminant analysis diagram and a hierarchical clustering analysis diagram of the colorimetric results are drawn using Matlab and Originlab. A 6-channel colorimetric sensor array is constructed in combination with the color development results obtained by a colorimetric plate, and 6 phenols are identified and analyzed. Different phenolic compounds can be identified and analyzed based on the differences in the spectra and the colorimetric results.

10. The colorimetric sensor array according to claim 9, characterized in that The color developer is one of 4-AAP and TMB.

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