阅读说明：本技术 多孔氧化石墨烯变色复合薄膜及其制备方法 (Porous graphene oxide color-changing composite film and preparation method thereof ) 是由 张瑞秀 于 2020-05-22 设计创作，主要内容包括：本发明涉及一种多孔氧化石墨烯变色复合薄膜,包括多孔泡沫镍基底,负载于多孔泡沫镍基底表面的多孔氧化石墨烯,偶联接枝在多孔氧化石墨烯上的氨基硅烷,以及修饰在氨基硅烷上的2,6-二(2-吡啶基)异烟酸基团。以泡沫镍为基底,将原料纳米石墨粉通过超声振动的方式渗透到其多孔结构中,然后再进行原位氧化,使得氧化得到的氧化石墨烯稳定地负载在多孔泡沫镍基底表面,并得到相应的多孔氧化石墨烯结构,该多孔氧化石墨烯结构稳定、可靠,能够提供丰富、稳定的多孔结构。同时,配合氨基硅烷的偶联接枝和2,6-二(2-吡啶基)异烟酸基团的表面修饰,可以得到性能稳定的电化学发光传感器用石墨烯基复合薄膜。(The invention relates to a porous graphene oxide color-changing composite film which comprises a porous foam nickel substrate, porous graphene oxide loaded on the surface of the porous foam nickel substrate, aminosilane coupled and grafted on the porous graphene oxide, and 2, 6-di (2-pyridyl) isonicotinic acid group modified on the aminosilane. The method comprises the steps of taking foamed nickel as a substrate, permeating raw material nano graphite powder into a porous structure of the foamed nickel in an ultrasonic vibration mode, and then carrying out in-situ oxidation, so that oxidized graphene obtained by oxidation is stably loaded on the surface of the porous foamed nickel substrate, and a corresponding porous oxidized graphene structure is obtained. Meanwhile, the graphene-based composite film for the electrochemical luminescence sensor with stable performance can be obtained by matching with the coupling grafting of aminosilane and the surface modification of 2, 6-di (2-pyridyl) isonicotinic acid group.)

1. A porous graphene oxide color-changing composite film comprises a porous foam nickel substrate, porous graphene oxide loaded on the surface of the porous foam nickel substrate, aminosilane coupled and grafted on the porous graphene oxide, and 2, 6-di (2-pyridyl) isonicotinic acid group modified on the aminosilane.

2. The preparation method of the porous graphene oxide color-changing composite film according to claim 1, comprising the following steps:

(1) cleaning the porous foam nickel substrate, removing an oxide film on the surface, then embedding the cleaned porous foam nickel substrate into nano graphite powder, and ultrasonically vibrating to enable the nano graphite powder to permeate into pores of the porous foam nickel substrate for later use;

(2) immersing the porous foam nickel substrate permeated with the nano graphite powder into 200ml of concentrated sulfuric acid solution, then adding 20-50ml of potassium permanganate solution, uniformly stirring, heating to 80-90 ℃, dropwise adding hydrogen peroxide and simultaneously applying ultrasonic vibration to perform oxidation reaction to obtain graphite oxide, then performing ultrasonic cleaning with deionized water to remove unreacted graphite powder precipitate, and obtaining porous graphene oxide stably loaded on the surface of the porous foam nickel substrate;

(3) immersing the prepared porous foam nickel substrate with the surface loaded with the porous graphene oxide into an ethanol solution of an aminosilane coupling agent, and carrying out coupling grafting reaction at the temperature of 60-80 ℃;

(4) immersing the porous foam nickel substrate subjected to silane coupling and grafting reaction into a tetrahydrofuran solution of 2, 6-di (2-pyridyl) isonicotinic acid, then adding tripropylamine, and carrying out heating reaction so as to stably modify 2, 6-di (2-pyridyl) isonicotinic acid groups on the surface of the porous graphene oxide.

3. The method of claim 2, wherein: in the step (1), the size of the porous foam nickel substrate is 2cm multiplied by 2cm, the thickness is 0.1-1mm, and the particle size of the nano graphite powder is 20-500 nm.

4. The method of claim 2, wherein: in the step (1), the pore diameter of the porous foam nickel substrate is 1-100 um.

5. The method of claim 2, wherein: in the step (2), the concentrated sulfuric acid is 98% concentrated sulfuric acid by mass percent.

Technical Field

The invention belongs to the field of graphene oxide composite film preparation, and particularly relates to a porous graphene oxide color-changing composite film and a preparation method thereof.

Background

The graphene has excellent optical, electrical and mechanical properties, has important application prospects in the aspects of materials science, micro-nano processing, energy, sensing detection, biomedicine, drug delivery and the like, and is considered to be a revolutionary material in the future.

Particularly, in the aspect of sensing detection, the ruthenium-doped zinc oxide is often matched with terpyridyl ruthenium and is widely applied to the preparation of an electrochemical luminescence sensor. Wherein, terpyridyl ruthenium ([ Ru (bpy) 3)²⁺]) Is a commonly used material for an electrochemiluminescence probe, and has easy operation and high flexibilitySensitivity and the like, and can be used in various fields of detection analysis, environmental analysis and the like of medical drugs. However, in the current terpyridyl ruthenium electrochemiluminescence sensor, a dispersion liquid of graphene is generally used as a base, and in the dispersion liquid, the graphene is easily subjected to strong interaction to form a thin film structure on the surface of an electrode, so that a pore structure on the surface of the electrode is covered, and the effect of the electrochemical sensor is finally influenced.

Therefore, a researcher proposes that porous graphene can be used as a basis, even if strong interaction exists in the dispersion liquid, the graphene can further form a film, the porous structure on the surface of the electrode can not be completely covered, the effect of the electrochemical sensor cannot be affected, the porous structure can provide a larger specific surface area, and the sensing effect of the electrochemical sensor can be enhanced. However, the existing method for preparing the liquid nitrogen frozen graphene dispersion liquid of the porous graphene is not stable in pore structure, so that the prepared electrochemical sensor is insufficient in stability.

Furthermore, based on graphene quantum dots, researchers try to modify the surfaces of the graphene quantum dots with silane and then modify the surfaces with terpyridine groups, so that the ion interference resistance of the sensor can be improved, and the application range of the sensor in the aspects of spectrometry and colorimetric sensing is widened. However, the prepared graphene quantum dots are dispersed particles, and the physical size of the finally obtained terpyridine modified graphene quantum dot composite material is limited, so that the actual application is limited, and the graphene quantum dot composite material is only suitable for laboratories.

Therefore, a graphene oxide color-changing composite film which is simple and convenient in preparation method, stable in performance and suitable for large-scale practical application needs to be developed.

Disclosure of Invention

In order to solve the defects of the existing graphene-based electrochemical luminescence sensor, the invention provides a porous graphene oxide color-changing composite film and a preparation method thereof.

A porous graphene oxide color-changing composite film comprises a porous foam nickel substrate, porous graphene oxide loaded on the surface of the porous foam nickel substrate, aminosilane coupled and grafted on the porous graphene oxide, and 2, 6-di (2-pyridyl) isonicotinic acid group modified on the aminosilane.

The preparation method of the porous graphene oxide color-changing composite film comprises the following steps:

(1) cleaning the porous foam nickel substrate, removing an oxide film on the surface, then embedding the cleaned porous foam nickel substrate into nano graphite powder, and ultrasonically vibrating to enable the nano graphite powder to permeate into pores of the porous foam nickel substrate for later use;

(2) immersing the porous foam nickel substrate permeated with the nano graphite powder into 200ml of concentrated sulfuric acid solution, then adding 20-50ml of potassium permanganate solution, uniformly stirring, heating to 80-90 ℃, dropwise adding hydrogen peroxide and simultaneously applying ultrasonic vibration to perform oxidation reaction to obtain graphite oxide, then performing ultrasonic cleaning with deionized water to remove unreacted graphite powder precipitate, and obtaining porous graphene oxide stably loaded on the surface of the porous foam nickel substrate;

(3) immersing the prepared porous foam nickel substrate with the surface loaded with the porous graphene oxide into an ethanol solution of an aminosilane coupling agent, and carrying out coupling grafting reaction at the temperature of 60-80 ℃;

(4) immersing the porous foam nickel substrate subjected to silane coupling and grafting reaction into a tetrahydrofuran solution of 2, 6-di (2-pyridyl) isonicotinic acid, then adding tripropylamine, and carrying out heating reaction so as to stably modify 2, 6-di (2-pyridyl) isonicotinic acid groups on the surface of the porous graphene oxide.

Further, in the step (1), the size of the porous foamed nickel substrate is 2cm multiplied by 2cm, the thickness is 0.1-1mm, and the particle size of the nano graphite powder is 20-500 nm.

Further, in the step (1), the pore diameter of the porous foam nickel substrate is 1-100 um.

Further, in the step (2), the concentrated sulfuric acid is a concentrated sulfuric acid with a mass percentage concentration of 98%.

The content of the invention also comprises the step of applying the prepared porous graphene oxide color-changing composite film to an electrochemical luminescence sensor, and the porous graphene oxide color-changing composite film is particularly used in detection and analysis of medical drugs or environmental detection and analysis.

Compared with the graphene-based composite film used in the existing electrochemical luminescence sensor, the porous graphene oxide color-changing composite film has the following advantages:

1. according to the invention, foam nickel is used as a substrate, raw material nano graphite powder permeates into a porous structure of the foam nickel in an ultrasonic vibration mode, and then in-situ oxidation is carried out, so that oxidized graphene obtained by oxidation is stably loaded on the surface of the porous foam nickel substrate, and a corresponding porous oxidized graphene structure is obtained.

2. In the invention, the foamed nickel is directly used as a substrate to provide guarantee for preparing the graphene-based composite film with a certain size and scale. Meanwhile, the foam nickel substrate can be directly used as an electrode, the adhesion performance between the graphene oxide and the foam nickel substrate used as the electrode is stable, and a guarantee is provided for preparing an electrochemical sensor with stable performance.

3. According to the invention, the surface of the graphene oxide is subjected to coupling grafting of the silane coupling agent, so that an amino group is primarily modified on the surface of the graphene oxide, the subsequent stable modification of the 2, 6-bis (2-pyridyl) isonicotinic acid group on the surface of the porous graphene oxide is ensured, and the stability of the electrochemical luminescence sensor is improved.

4. The porous graphene oxide color-changing composite film can be directly applied to an electrochemical luminescence sensor, and is simple to prepare and stable in performance.

Detailed Description

In order to explain the technical solution of the present invention in detail, the following provides a preferred embodiment of the present invention.