CN109848439B

CN109848439B - Preparation method of silver nanosheet

Info

Publication number: CN109848439B
Application number: CN201910280707.5A
Authority: CN
Inventors: 赖跃坤; 董秀丽; 高寿伟; 黄剑莹
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2019-04-09
Filing date: 2019-04-09
Publication date: 2022-03-15
Anticipated expiration: 2039-04-09
Also published as: CN109848439A

Abstract

The invention discloses a preparation method of silver nanosheets, which comprises the following steps: dissolving dopamine, copper sulfate and hydrogen peroxide in a Tris buffer solution in sequence, mechanically stirring for a certain time, and centrifuging to obtain polydopamine; and finally, dripping the polydopamine solution into a mixed solution of silver nitrate and copper sulfate, and mechanically stirring and reacting for a period of time to obtain the silver nanosheet. The method has the advantages of simple process, mild reaction conditions, low cost, good repeatability and good application prospect.

Description

Preparation method of silver nanosheet

Technical Field

The invention relates to a preparation method of a silver nanosheet.

Background

Since the nano material has unique small-size effect, surface effect, quantum size effect and macroscopic quantum tunneling effect, it exhibits characteristics different from conventional materials in various aspects of light, electricity, magnetism, heat, and the like. The silver nano material not only retains the inherent characteristics of the nano material, but also has the characteristics of good conductivity, chemical stability, high plasticity, oxidation resistance and the like, and is widely applied to various fields of chemical catalysis, detection, energy, printing, biology, even photoelectricity and the like. Due to the tunable spectral peak and very high optical efficiency of silver nanoplates, also known as silver flake nanoparticles, methods have been developed to make silver nanoplates by photo-conversion, pH controlled photo-conversion, thermal growth, templated growth, and the like. But the preparation process is relatively complex, the reaction conditions are harsh, the cost is high, the environment is not protected, and the repeatability is poor.

Therefore, it is necessary to provide a further solution to the above problems.

Disclosure of Invention

The invention aims to provide a preparation method of silver nanosheets, and solves the problems.

The technical scheme of the invention is as follows:

a preparation method of silver nanosheets comprises the following steps:

(1) preparation of polydopamine solution: sequentially dissolving dopamine, copper sulfate and hydrogen peroxide in a Tris buffer solution, mechanically stirring, and centrifuging to obtain a polydopamine solution;

(2) preparing silver nanosheets: and (3) dripping the polydopamine solution into a mixed solution of silver nitrate and copper sulfate, and mechanically stirring to obtain the silver nanosheet.

Further, in the step (1), the dopamine is dopamine hydrochloride, and the concentration of the dopamine is 1-5 mg/mL.

Further, the copper sulfate in the step (1) is copper sulfate pentahydrate, and the concentration of the copper sulfate is 3-8 mmol/L.

Further, the concentration of the hydrogen peroxide in the step (1) is 15-20 mmol/L.

Further, in the step (1), the pH value of the Tris buffer solution is 7-10.

Further, the rotation speed of the centrifugation in the step (1) is 8000rpm, and the time is 10 min.

Further, the mechanical stirring time in the steps (1) and (2) is 30-120 min.

Further, the concentration of the polydopamine solution in the step (2) is 10-20 mg/mL.

Further, in the step (2), the concentration of the silver nitrate is 0.1-1 mmol/L, and the concentration of the copper sulfate is 0.02-4 mmol/L.

Further, the thickness of the silver nanosheet in the step (2) is 5-20 nm.

The invention provides a preparation method of silver nanosheets, which is characterized in that the silver nanosheets are prepared by a two-step method, and silver nitrate is reduced by dopamine. The method has the advantages of extremely simple process and equipment required by production, mild reaction conditions, low cost and good repeatability, and can be directly applied to large-scale industrial production. The silver nanosheet prepared by the method has excellent photo-thermal conversion performance and electrocatalysis performance.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein the content of the first and second substances,

FIG. 1 is a desktop electron microscope image and a silver element distribution diagram of a silver nanosheet prepared by the method for preparing the silver nanosheet of the present invention;

fig. 2 is an absorption spectrum of a dispersion solution prepared using one silver nanosheet of the present invention;

fig. 3 is a TEM image of polydopamine prepared in example 1 in a method of preparing silver nanoplates according to the present invention;

fig. 4 is a TEM image of silver nanoplates prepared in example 1 in a method of preparing silver nanoplates according to the present invention;

fig. 5 is a TEM image of silver nanoplates prepared in example 2 in a method of preparing silver nanoplates according to the present invention;

fig. 6 is a TEM image of the silver nanosheet prepared in example 3 of the method for preparing silver nanosheets of the present invention.

Detailed Description

The invention provides a preparation method of a silver nanosheet, which comprises the following steps:

(1) preparing a polydopamine solution;

(2) and (4) preparing silver nano sheets.

The present invention will be described in further detail with reference to specific embodiments in order to make the above objects, features and advantages more apparent and understandable.

The method comprises the following steps: preparation of polydopamine particles

In one embodiment, this step may be specifically performed as follows: sequentially dissolving 2-5 g of dopamine, 0.1-0.3 g of copper sulfate and 0.2-0.5 mL of hydrogen peroxide in 100-200 mL of Tris buffer solution with pH value of 7-10, mechanically stirring for 30-120 min, and centrifuging for multiple times to prepare polydopamine particles;

step two: preparation of silver nanoplates

In one embodiment, this step may be specifically performed as follows: dissolving 0.017-0.17 g of silver nitrate and 0.06-0.6 g of copper sulfate in 50-100 mL of deionized water, then dropwise adding 1-4 mL of polydopamine solution in the first step, and mechanically stirring for 30-120 min to obtain the silver nanosheets.

Referring to fig. 1, fig. 1 is a desktop electron microscope image and a silver element distribution diagram of a silver nanosheet prepared by the method for preparing a silver nanosheet of the present invention. As shown in fig. 1, after scanning of the prepared silver nanosheet by a desktop electron microscope, the blocks are distributed as silver elements, so that the poly-dopamine layer on the surface of the substrate can successfully reduce silver ions to obtain the silver nanomaterial. Referring to fig. 2, fig. 2 is a light absorption spectrum of a dispersion solution prepared by using silver nano-sheets according to the present invention. As can be seen from fig. 2, the silver nanomaterial is dispersed in the reacted solution and conforms to the absorption spectrum of silver.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are further described below. The invention is not limited to the embodiments listed but also comprises any other known variations within the scope of the invention as claimed.

First, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

The present invention is described in detail by using the schematic structural diagrams, etc., and for convenience of illustration, the schematic diagrams are not enlarged partially according to the general scale when describing the embodiments of the present invention, and the schematic diagrams are only examples, which should not limit the scope of the present invention. In addition, the actual fabrication process should include three-dimensional space of length, width and depth.

In addition, the acronyms referred to in the invention are all fixed acronyms in the field, wherein part of the letters are explained as follows: tris (Tris): tris (hydroxymethyl) aminomethane; TEM image: transmission electron scanning image display.

Example 1

The embodiment shows a preparation method of silver nanosheets according to the following steps:

(1) preparation of polydopamine solution: dissolving 2g of dopamine, 0.1g of copper sulfate and 0.2mL of hydrogen peroxide in 100mL of Tris buffer solution in sequence, mechanically stirring for 45min, and centrifuging for multiple times to obtain the polydopamine solution.

(2) Preparing silver nanosheets: and (2) dissolving 0.05g of silver nitrate and 0.1g of copper sulfate in 50mL of deionized water, then dropwise adding 1mL of polydopamine solution obtained in the step (1), and mechanically stirring to react for 30min to obtain the silver nanosheets.

Please refer to fig. 3 to 4 for the morphology structure of the polydopamine prepared in this embodiment, fig. 3 is a TEM image of the polydopamine prepared in example 1 in the preparation method of silver nanosheets, and fig. 4 is a TEM image of the silver nanosheets prepared in example 1 in the preparation method of silver nanosheets. As shown in fig. 3, the polydopamine obtained by the step (1) of the method is successfully prepared, and the prepared polydopamine is granular aggregate. As shown in fig. 4, the size of the prepared silver nanoplatelets is about 500 nm.

Example 2

(1) preparation of polydopamine solution: 3g of dopamine, 0.15g of copper sulfate and 0.3mL of hydrogen peroxide are sequentially dissolved in 150mL of Tris buffer solution, mechanically stirred for 60min and centrifuged for multiple times to prepare the polydopamine solution.

(2) Preparing silver nanosheets: and (3) dissolving 0.1g of silver nitrate and 0.15g of copper sulfate in 75mL of deionized water, then dropwise adding 2mL of polydopamine solution obtained in the step (1), and mechanically stirring to react for 45min to obtain the silver nanosheets.

Please refer to fig. 5 for a morphology structure of polydopamine prepared in this embodiment, wherein fig. 5 is a TEM image of a silver nanosheet prepared in example 2 of the preparation method of a silver nanosheet according to the present invention. As shown in fig. 5, the size of the prepared silver nanoplatelets is about 200 nm.

Example 3

(1) preparation of polydopamine solution: dissolving 4g of dopamine, 0.2g of copper sulfate and 0.4mL of hydrogen peroxide in 200mL of Tris buffer solution in sequence, mechanically stirring for 60min, and centrifuging for multiple times to obtain the polydopamine solution.

(2) Preparing silver nanosheets: 0.15g of silver nitrate and 0.21g of copper sulfate were dissolved in 100mL of deionized water, and then 3mL of the polydopamine solution in step (1) was added dropwise.

And (3) dripping the prepared polydopamine solution into a mixed solution of silver nitrate and copper sulfate, and reacting for 60min by mechanical stirring to obtain the silver nanosheet.

Please refer to fig. 6 for the morphology structure of polydopamine prepared in this embodiment, and fig. 6 is a TEM image of silver nanosheets prepared in embodiment 3 of the method for preparing silver nanosheets of the present invention. As shown in fig. 6, the size of the prepared silver nanoplatelets is about 1000 nm.

It can be seen that in the above three examples, silver nanoplates with uniform thickness can be prepared by the method.

Compared with the prior art, the invention has the beneficial effects that: the preparation method of the silver nanosheet is simple in process, mild in reaction condition, low in raw material cost, green and environment-friendly, does not need to add a surfactant or a stabilizer, and is good in repeatability. The prepared silver nanosheet has excellent photo-thermal conversion performance and electro-catalysis performance, and has a good application prospect.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. A preparation method of silver nanosheets is characterized by comprising the following steps:

(1) preparation of polydopamine solution: sequentially dissolving dopamine, copper sulfate and hydrogen peroxide in a Tris buffer solution, mechanically stirring, and centrifuging to obtain a polydopamine solution, wherein the dopamine is dopamine hydrochloride, the concentration of the dopamine is 1-5 mg/mL, the copper sulfate is copper sulfate pentahydrate, the concentration of the copper sulfate is 3-8 mmol/L, the concentration of the hydrogen peroxide is 15-20 mmol/L, the pH value of the Tris buffer solution is 7-10, the rotation speed of centrifugation is 8000rpm, the time is 10min, and the time of mechanical stirring is 30-120 min;

(2) preparing silver nanosheets: and dropping the polydopamine solution into a mixed solution of silver nitrate and copper sulfate, and mechanically stirring to obtain silver nanosheets, wherein the mechanical stirring time is 30-120 min, the concentration of the polydopamine solution is 10-20 mg/mL, the concentration of the silver nitrate is 0.1-1 mmol/L, the concentration of the copper sulfate is 0.02-4 mmol/L, and the thickness of the silver nanosheets is 5-20 nm.