CN113036164A

CN113036164A - Preparation method and application of composite electrode based on mesoporous carbon foam

Info

Publication number: CN113036164A
Application number: CN201911344995.2A
Authority: CN
Inventors: 孙晶; 曹厚勇; 郎明非
Original assignee: Dalian University
Current assignee: Dalian University
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-06-25
Anticipated expiration: 2039-12-24
Also published as: CN113036164B

Abstract

A preparation method and application of a composite electrode based on mesoporous carbon foam belong to the field of fuel cells. The mesoporous foam carbon composite electrode firstly treats MFC, then carries out flower-shaped nano-gold deposition, and finally carries out the preparation of the Ni-Au/MFC composite electrode. The motor is applied to a three-electrode system which is formed by taking a NiNPs/AuNPs/MFC electrode as a working electrode, an Ag/AgCl electrode as a reference electrode and a platinum wire as an auxiliary electrode, placing the three-electrode system in a maltose solution and a supporting electrolyte, setting the potential to be-0.2-1.3V, recording a cyclic voltammetry curve of 10mmol/L maltose with the scanning speed range of 20-100 mV/S, and analyzing the control process of the electrode electrocatalytic oxidation of the maltose solution by using a standard curve method. The electrode with high sensitivity to maltose is prepared by utilizing the good conductivity of MFC, and has the advantages of good catalytic effect, high sensitivity, good selectivity, stable structure and the like when maltose is used as a base solution.

Description

Preparation method and application of composite electrode based on mesoporous carbon foam

Technical Field

The invention belongs to the field of fuel cells, and particularly relates to a preparation method and application of a composite electrode based on mesoporous carbon foam.

Background

With the development of society, the demand for fossil fuels is rapidly increasing, and the exhaustion of fossil fuels and the serious pollution to the environment are accelerated, thereby limiting the development of human society and seriously affecting human health. To mitigate the environmental pollution and human health impact of fossil fuels, it is important to find alternatives to fossil fuels. The technical research and development and utilization of renewable energy resources are actively and widely carried out all over the world at present. At present, main substitutes of fossil fuels include biodiesel, liquid hydrogen, solar energy, wind energy and the like, and fuel cells are also substitutes of fossil fuels. However, the conductivity of the substrate material of the current fuel cell is poor, and the sensitivity of the fuel cell is affected.

MFC, More foam carbon, is a material having a mesoporous structure with a high specific surface area like a trumpet flower inside, and is as soft as a foam.

Disclosure of Invention

In order to overcome the defects, the invention provides a preparation method and application of a composite electrode based on mesoporous carbon foam.

The preparation method of the mesoporous carbon foam composite electrode comprises the following steps:

(1) MFC treatment;

(2) depositing flower-shaped nano gold;

(3) and (3) preparing the Ni-Au/MFC composite electrode.

The method comprises the steps of taking a NiNPs/AuNPs/MFC electrode as a working electrode, an Ag/AgCl electrode as a reference electrode and a platinum wire as an auxiliary electrode to form a three-electrode system, placing the three-electrode system in a maltose solution and a supporting electrolyte, setting the potential to be-0.2-1.3V, recording a cyclic voltammetry curve of 10mmol/L maltose with the scanning speed range of 20-100 mV/S, and analyzing the control process of the electrode in the electrocatalytic oxidation of the maltose solution by using a standard curve method.

Further, the supporting electrolyte is 1mol/LKOH, and the pH is 14.

Further, the NiNPs/AuNPs/MFC electrode includes: mesoporous Foam Carbon (MFC) is used as a substrate and a conducting layer, nano nickel-gold particles are used as an electrochemical deposition layer, the nano nickel particles are deposited on the nano gold particles, and the nano gold particles are deposited on the MFC.

The principle is as follows: the MFC is of a uniform porous structure, has a huge specific surface area and a three-dimensional pore structure, and has good conductivity, so that a large number of uniform nano nickel particles can be deposited, the area of the nano gold attached to the nano nickel is increased, the contact area of the nano gold on maltose is enlarged, the current of the nano gold is increased, the output power of a battery is increased, and the electrode has high sensitivity to maltose. And when maltose is taken as a reference solution, the good catalytic performance and high selectivity can be shown.

Has the advantages that: the electrode with high sensitivity to maltose is prepared by utilizing the good conductivity of the MFC, and has the advantages of good catalytic effect, high sensitivity, good selectivity, stable structure and the like when the maltose is used as a base liquid.

Drawings

FIG. 1 is a surface topography of a nano-Au/nano-Ni composite electrode based on MFC.

FIG. 2 is a comparison of cyclic voltammograms of maltose solution and a blank solution.

FIG. 3 is a plot of cyclic voltammograms of maltose solutions at different sweep rates.

FIG. 4 is a standard curve of maltose at different sweep rates.

FIG. 5 is a NiNPs/AuNPs/MFC electrode anti-poisoning curve.

Detailed Description

The technical solutions of the present invention are further described below with reference to examples, but the present invention is not limited to the contents of the examples in any way. In the examples, unless otherwise specified, the experimental methods are all conventional methods; unless otherwise indicated, the experimental reagents and materials were commercially available.

EXAMPLE 1 preparation of NiNPs/AuNPs/MFC electrodes

(4) MFC processing

And taking a piece of MFC for standby, ultrasonically cleaning MFC glass for 30 minutes by using deionized water, taking out, washing by using the deionized water, and drying by using nitrogen for standby.

(2) Flower-like nano gold deposition

Using a three-electrode system, with MFC electrode immersionInto H₂SO₄(0.5M) and KAuCl₄(1mg/m L) in the mixture, a platinum electrode was used as a counter electrode and Ag/Ag Cl as a reference electrode. Setting electrodeposition parameters of an electrochemical workstation by adopting square wave voltammetry: initial voltage-0.2V, end point potential: -0.9V, potential increment: 0.05V, amplitude 0.025V, frequency 20 HZ. And (5) carrying out nitrogen protection on the electrode after deposition, and standing for standby after three days.

(3) Preparation of Ni-Au/MFC composite electrode

A three-electrode system is adopted, AuNPs/MFC with a nano structure is used as a working electrode, an Ag/AgCl electrode and a platinum wire electrode are used as reference electrodes, and a counter electrode is placed in an electrolytic cell filled with nickel sulfate solution. Setting electrodeposition parameters of an electrochemical workstation by adopting a potentiostatic method: voltage-1V, time 300 s. And immediately taking out the electrode, washing the electrode with deionized water for multiple times, and standing the electrode for later use under the protection of nitrogen after deposition.

Based on the MFC/nano nickel-gold composite electrode surface topography as shown in figure 1, the nano-particle size and distribution on the electrode are uniform, and the electrocatalytic performance is particularly outstanding.

Example 2 comparison of cyclic voltammograms of maltose solution and blank solution

Firstly, placing a three-electrode system in a KOH solution with the pH of 14 and the concentration of 1mol/L, scanning within a potential range of-0.2-1.3V by using a cyclic voltammetry method, and recording a cyclic voltammetry curve of a blank solution; then, the three-electrode system is placed in 10mmol/L maltose solution to be detected containing 1mol/L KOH solution with pH of 14 as supporting electrolyte, and scanning is carried out in a potential range of-0.2-1.3V by using cyclic voltammetry, and the cyclic voltammetry curve of maltose is recorded. As shown in fig. 2: the catalytic effect of the Au-Ni electrode at 10mmol/L maltose was tested at a scan rate of 100 mV/s. From the figure, it can be seen that the Au-Ni electrode has a good catalytic activity for maltose. The fuel composed of the Ni-Au/MFC electrode can convert the biological energy into the electric energy with high efficiency.

Example 3 Cyclic voltammetric response of NiNPs/AuNPs/MFC electrodes to maltose of the same concentration at different sweep rates

Sequentially placing the three-electrode system in a 10mm maltose solution to be detected containing 1mol/L KOH solution with the pH value of 14 as a supporting electrolyte, testing the maltose solutions with different sweep rates at the same concentration, wherein the sweep rates are respectively 20m V/s, 40m V/s, 60m V/s, 80mV/s and 100m V/s, and scanning within a potential range of-0.2-1.3V by using a cyclic voltammetry. Cyclic voltammograms of maltose at the same concentration and different sweep rates were recorded. As shown in the attached figures 3 and 4: as can be seen from the figure, with the continuous increase of the sweep rate, the oxidation current of the nano electrode in the maltose solution is also continuously increased, the oxidation peak is also continuously increased, and a good linear response for catalyzing maltose is presented, so that the Au-Ni electrode can be proved to be used for catalyzing maltose to be diffusion control.

Example 4 NiNPs/AuNPs/MFC electrode anti-poisoning Curve

First, a three-electrode system was placed in a 10mm maltose test solution containing 1mol/L KOH solution having a pH of 14 as a supporting electrolyte, and a time-current curve of maltose was recorded at a potential of 0.6V by the time-current method. However, as shown in fig. 5, the current density drops sharply at the beginning. At the beginning of the reaction, it is a fast kinetic reaction, so the active site does not contain adsorbed maltose molecules. Thereafter, adsorption of the neomaltose molecules depends on the release of the electrode catalytic sites by oxidation of maltose, or the electrode catalytic active sites are occupied by intermediate species such as CO, CHx, etc. formed in the first few minutes (rate determining step). Therefore, the slight decrease in current density is mainly due to the poisoning of the catalyst. Furthermore, the specific current experienced a rapid drop during the first 300 seconds throughout the test and was still a smooth and gentle change after the end of the test, with a decay of about 9%.

The above description is only for the purpose of creating a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims

1. A composite electrode preparation method based on mesoporous foam carbon is characterized by comprising the following preparation steps:

s1, MFC treatment;

s2, depositing flower-shaped nano gold;

and S3, preparing the Ni-Au/MFC composite electrode.

2. The method for preparing a composite electrode based on mesoporous carbon foam according to claim 1, wherein the step S1 comprises the following steps: and taking a piece of MFC for standby, ultrasonically cleaning MFC glass for 30 minutes by using deionized water, taking out, washing by using the deionized water, and drying by using nitrogen for standby.

3. The method for preparing a composite electrode based on mesoporous carbon foam according to claim 1, wherein the patterned nanogold is deposited by using a three-electrode system in step S2, and is immersed in H through an MFC electrode₂SO₄0.5M and KAuCl₄1mg/m L mixture, using a platinum electrode as the counter electrode and Ag/Ag Cl as the reference electrode; setting electrodeposition parameters of an electrochemical workstation by adopting square wave voltammetry: initial voltage-0.2V, end point potential: -0.9V, potential increment: 0.05V, amplitude 0.025V, frequency 20HZ, electrode nitrogen protection after deposition, standing for three days for later use.

4. The method for preparing a composite electrode based on mesoporous carbon foam according to claim 1, wherein the Ni-Au/MFC composite electrode in step S3 is prepared by using a three-electrode system, using a nano-structured AuNPs/MFC as a working electrode, using an Ag/AgCl electrode and a platinum wire electrode as reference electrodes, and placing the reference electrodes and the counter electrode into an electrolytic cell containing a nickel sulfate solution; setting electrodeposition parameters of an electrochemical workstation by adopting a potentiostatic method: voltage-1V and time 300 s; and immediately taking out the electrode, washing the electrode with deionized water for multiple times, and standing the electrode for later use under the protection of nitrogen after deposition.

5. The application of the mesoporous carbon foam-based composite electrode is characterized in that a NiNPs/AuNPs/MFC electrode is used as a working electrode, an Ag/AgCl electrode is used as a reference electrode, a platinum wire is used as an auxiliary electrode to form a three-electrode system, the three-electrode system is placed in a maltose solution and a supporting electrolyte, the set potential is-0.2-1.3V, a cyclic voltammetry curve of 10mmol/L maltose with the scanning speed range of 20-100 mV/S is recorded, and the control process of the electrode electrocatalytic oxidation of the maltose solution is analyzed by using a standard curve method.

6. The use of a mesoporous carbon foam-based composite electrode according to claim 5, wherein the supporting electrolyte is 1mol/LKOH and the pH is 14.