阅读说明：本技术 一种铜离子鳌合的石墨相单层c3n4纳米酶及其制备方法 (Graphite phase single layer C chelated with copper ions3N4Nano enzyme and preparation method thereof ) 是由 渠陆陆 方雪娇 杨国海 谷迎秋 张凡利 于 2020-12-23 设计创作，主要内容包括：一种铜离子鳌合的石墨相单层C-3N-4纳米酶的制备方法,包括：将三聚氰胺煅烧4h,得到鲜黄色块状样品a。随后,将大量的a在研钵中研磨成粉末,然后放入燃烧舟中加热1h,所得淡黄色样品b。将样品b再加热1h,最终获得的白色样品c。将样品c溶于水溶液中得到溶液d。超声处理10min,将CuCl-2溶于水中得到溶液e,向溶液d中加入溶液e得到混合溶液f,超声处理4h。接下来,离心分离混合溶液f,并用超纯水洗涤以除去未结合的CuCl-2。最后,将产物干燥得到铜离子鳌合的的石墨相单层C-3N-4纳米酶材料。本发明的方法以三聚氰胺,CuCl-2为前驱体,通过煅烧,超声来构筑铜离子鳌合的的石墨相单层C-3N-4纳米酶材料,改善了C-3N-4纳米酶催化活性。(Graphite phase single layer C chelated with copper ions 3 N 4 The preparation method of the nano enzyme comprises the following steps: the melamine was calcined for 4h to give a bright yellow block sample a. Subsequently, a large amount of a was ground into powder in a mortar and then placed in a combustion boat to be heated for 1h, resulting in a pale yellow sample b. Sample b was heated for an additional 1h to obtain white sample c. The sample c was dissolved in an aqueous solution to obtain a solution d. Sonicating for 10min to remove CuCl 2 Dissolving in water to obtain a solution e, adding the solution e into the solution d to obtain a mixed solution f, and carrying out ultrasonic treatment for 4 h. Next, the mixed solution f was centrifuged, and washed with ultrapure water to remove unbound CuCl 2 . Finally, the product is dried to obtain a copper ion chelated graphite phase monolayer C 3 N 4 And (3) nano enzyme material. The method of the invention uses melamine, CuCl 2 The graphite phase monolayer C chelated with copper ions is constructed by calcination and ultrasound as a precursor 3 N 4 Nano enzyme material, improve C 3 N 4 And (3) catalyzing activity by the nano enzyme.)

1. Graphite phase single layer C chelated with copper ions₃N₄The preparation method of the nano enzyme is characterized by comprising the following steps:

s1: calcining melamine for 4 hours to obtain a fresh yellow massive sample a; grinding a large amount of a into powder in a mortar, and then putting the powder into a combustion boat to heat for 1h to obtain a light yellow sample b; heating the sample b for 1h again to finally obtain a white sample c;

s2: dissolving the sample c in an aqueous solution to obtain a solution d, and carrying out ultrasonic treatment for 10 min; adding CuCl₂Dissolving in water to obtain a solution e;

s3: adding the solution e to the solution d to obtain a mixed solution f, performing ultrasonic treatment for 4h, centrifuging the mixed solution f, and washing with ultrapure water to remove unbound CuCl₂Finally, the product is dried to obtain a copper ion chelated graphite phase monolayer C₃N₄And (3) nano enzyme material.

2. The method according to claim 1, wherein the sample a is heated at 550 ℃ at 2 ℃/min.

3. The method according to claim 1, wherein the sample b is heated at 550 ℃ at 5 ℃/min.

4. The method according to claim 1, wherein the sample c is heated at 550 ℃ at 2 ℃/min.

5. The method according to claim 1, wherein in step S2, the concentration of solution d is 1 mg/mL.

6. The method according to claim 1, wherein in the step S2, the concentration of the solution e is 0.1M/L.

7. The method according to claim 1, wherein the volume ratio of the solution d to the solution e in the mixed solution f is 1: 1.

8. copper ion chelated graphitic phase monolayer C prepared by the method of any preceding claim₃N₄And (3) nano enzyme.

Technical Field

The invention relates to a nano enzyme, in particular to a copper ion doped monolayer C₃N₄Nano enzyme, its preparation method and application.

Background

Most natural enzymes are mainly protein, have catalytic function and are mainly characterized by high efficiency and high specificity to substrates. However, since most natural enzymes are proteins, the reaction needs to be carried out under extremely mild conditions, and when the reaction is subjected to heat, acid, alkali and the like, the structure of the reaction is easily changed, so that the catalytic activity of the reaction is reduced or even lost. In addition, natural enzymes are present in very low amounts in the organism and are difficult to obtain in large quantities, which makes them expensive. Therefore, chemists have been looking for alternatives to natural enzymes that are highly stable and inexpensive. Graphite phase C₃N₄Is a novel visible light response catalyst, can simulate the activity of natural enzymes, and has been researched a lot. The main mechanism is that photo-generated electrons and holes are generated under illumination, and radical molecules with strong oxidizing property are generated by oxidation-reduction reaction of the electrons and the holes to directly or indirectly completely oxidize molecules.

Disclosure of Invention

The invention aims to prepare a graphite phase monolayer C with copper ion chelation₃N₄The nano enzyme is beneficial to the transfer and transfer of photoproduction electrons and inhibits the recombination of photoproduction electron hole pairs, thereby greatly improving the catalytic activity.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

graphite phase single layer C chelated with copper ions₃N₄The preparation method of the nano enzyme comprises the following steps:

s1: calcining melamine for 4 hours to obtain a fresh yellow massive sample a;

grinding a large amount of a into powder in a mortar, and then putting the powder into a combustion boat to heat for 1h to obtain a light yellow sample b;

heating the sample b for 1h again to finally obtain a white sample c;

s2: dissolving the sample c in an aqueous solution to obtain a solution d, and carrying out ultrasonic treatment for 10 min;

adding CuCl₂Dissolving in water to obtain a solution e;

s3: adding the solution e into the solution d to obtain a mixed solution f, and carrying out ultrafiltrationSonicated for 4h, centrifuged to separate the mixed solution f, and washed with ultrapure water to remove unbound CuCl₂Finally, the product is dried to obtain a copper ion chelated graphite phase monolayer C₃N₄And (3) nano enzyme material.

As a preferable technical scheme, the heating condition of the sample a is 550 ℃ and 2 ℃/min.

As a preferable technical scheme, the heating condition of the sample b is 550 ℃ and 5 ℃/min.

As a preferable technical scheme, the heating condition of the sample c is 550 ℃ and 2 ℃/min.

Preferably, in step S2, the concentration of solution d is 1 mg/mL.

Preferably, in step S2, the concentration of solution e is 0.1M/L.

As a preferable technical scheme, the volume ratio of the solution d to the solution e in the mixed solution f is 1: 1.

the invention also provides a graphite phase monolayer C with copper ion chelation prepared by the method₃N₄And (3) nano enzyme.

Compared with the prior art, the invention has the beneficial effects that:

the method uses melamine and copper chloride as precursors, and constructs the graphite phase single layer C chelated with copper ions by in-situ calcination and ultrasound₃N₄And (3) nano enzyme. The transfer and transfer of photoproduction electrons are improved through copper ion chelation, and the recombination of photoproduction electron hole pairs is inhibited, so that the catalytic activity is improved;

the method of the invention is to chelate copper ions to the graphite phase monolayer C₃N₄Surface, lowering C₃N₄The band gap accelerates the transfer and the transportation of a photon-generated carrier, inhibits the recombination rate of photon-generated electron hole pairs, promotes the generation of more catalytic active species, and is favorable for enhancing the catalytic efficiency.

Drawings

FIG. 1(A) copper ion chelated graphite phase monolayer C₃N₄Low power Transmission Electron Micrographs (TEM) of nanoenzyme material; (B) copper ion chelated graphitePhase monolayer C₃N₄High power transmission electron microscopy (HRTEM) of nanoenzyme material;

FIG. 2(A) copper ion chelated graphite phase monolayer C₃N₄Atomic Force Microscopy (AFM) of nanoenzyme materials; (B) copper ion chelated graphite phase monolayer C₃N₄Height map of nanoenzyme;

FIG. 3 copper ion chelated graphite phase monolayer C₃N₄An X-ray photoelectron spectrum (XPS) of the nano enzyme material;

FIG. 4 copper ion chelated graphite phase monolayer C₃N₄A catalytic activity diagram of the nano enzyme material under different pH (A) and temperature (B);

FIG. 5 copper ion chelated graphite phase monolayer C₃N₄The nano enzyme material has a glucose oxidase activity diagram;

FIG. 6 copper ion chelated graphite phase monolayer C₃N₄The nano enzyme material has a peroxidase activity pattern.

The specific implementation mode is as follows:

the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

1. Graphite phase single layer C chelated with copper ions₃N₄The preparation method of the nano enzyme material comprises the following steps:

melamine (2g) was calcined at 550 ℃ for 4h at a heating rate of 2 ℃/min to give a bright yellow block sample a. Subsequently, a large amount of a (500mg) was pulverized in a mortar and then put into a combustion boat to be heated at 550 ℃ for 1 hour at a heating rate of 5 ℃/min, resulting in a pale yellow sample b. B is heated at 550 ℃ for 1h at a heating rate of 2 ℃/min to finally obtain a white sample c. 10mg of c was dissolved in 10mL of an aqueous solution to form a solution d, and sonicated for 10 min. Adding CuCl₂Dissolved in water to formSolution e at a concentration of 0.1M/L. Subsequently, 10mL of solution e was added to solution d to form a mixed solution f, and sonicated at 50 ℃ for 4 h. Next, the mixed solution f was centrifuged, and washed four times with ultrapure water to remove unbound CuCl₂. Finally, the product is dried to obtain a graphite phase monolayer C chelated with copper ions₃N₄And (3) nano enzyme material. Fig. 1 is TEM (fig. 1A) and HRTEM (fig. 1B) of the product obtained by solvothermal under the experimental conditions described above. It can be seen from the TEM image that the graphite phase C chelated with copper ions₃N₄The nano enzyme material is separated, and no aggregation phenomenon exists, which shows that the dispersibility is better. From the height profile of fig. 2A along the solid line in the AFM image (fig. 2B), it can be seen that the thickness of MXene nanoplatelets is about 0.5 nm, indicating a graphitic monolayer C with copper ion chelation₃N₄The nanoenzyme material is a monolayer. As can be seen from the XPS plot of FIG. 3, successful copper ion sequestration to O-g-C is achieved₃N₄Graphite phase single layer C with copper ion chelating formed therein₃N₄And (3) nano enzyme material. FIG. 4 shows that the prepared copper ion chelated graphite phase monolayer C can be seen under different conditions of pH and temperature₃N₄The nano enzyme material has better catalytic activity under the conditions of heat, acid and alkali.

2. The above-mentioned copper ion chelated graphite phase single layer C₃N₄Catalytic activity of nano enzyme material:

copper ion chelated graphite phase monolayer C₃N₄The nano enzyme material has the activity of glucose oxidase. Accurately taking 2mL of Hcl-Tris buffer solution with pH value of 7, glucose with different concentrations and 100 mu L of graphite phase monolayer C chelated with copper ions₃N₄(1mg/mL) nanoenzyme material in a reactor. Reacting for 1h under the condition of illumination and oxygen introduction, taking 600 mu L of reaction liquid, adding 10 mu L of DPD (0.1M), reacting for 10min, observing the color change, and measuring the absorbance by using an ultraviolet-visible spectrophotometer. As shown in FIG. 5, the solution exhibited a red color and the UV spectrum responded at 551nm, indicating that the prepared copper ion chelated graphitic monolayer C₃N₄The nano enzyme material has the performance of glucose oxidase.

Copper ion chelated graphite phase monolayerC₃N₄The nano enzyme material has the activity of peroxidase. Accurately, 470. mu.L of pH 7 acetate buffer solution and 30. mu.L of copper ion chelated graphite phase monolayer C were taken₃N₄(1mg/mL) nanoenzyme material, 33.5. mu.L of 25mM TMB, 133.5. mu.L of 300mM H₂O₂In reactor No. 6. 470. mu.L of pH 7 acetate buffer, 33.5. mu.L of 25mM TMB, 133.5. mu.L of 300mM H were determined₂O₂In reactor No. 5. The reaction vessels No. 1, No. 2, No. 3 and No. 4 were charged with 470. mu.L of pH 7 acetic acid buffer solution and the corresponding reaction solution, 133.5. mu.L of H with a concentration of 300mM, respectively₂O₂33.5 μ L of 25mM TMB, 30 μ L of copper ion chelated graphitic phase monolayer C₃N₄(1mg/mL) of the nanoenzyme material and reacted for 10min, the color change thereof was observed, and the absorbance thereof was measured with an ultraviolet-visible spectrophotometer. As shown in FIG. 6, only the solution in reactor No. 6 exhibited a blue color and the UV spectrum responded at 652nm, indicating that the prepared copper ion chelated graphitic monolayer C₃N₄The nano enzyme material has the performance of peroxidase.