CN114774977A - A kind of sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, preparation method and application thereof - Google Patents

Abstract

The invention relates to the technical field of electrocatalysis, in particular to a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, a preparation method and an application thereof, wherein nickel nitrate, cerium nitrate and sodium thiosulfate are used as precursors, In situ growth of sulfur-doped nickel hydroxide-ceria composite nanorod arrays on nickel foam substrates by one-step hydrothermal method, this sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst has excellent The electrocatalytic water desorption oxygen reaction catalytic activity requires only an overpotential of 200mV at a current density of 10mA/ ^cm2 , and has good stability, meeting the requirements of large-scale industrial applications.

Description

A kind of sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, preparation method and application thereof

technical field

The invention relates to the technical field of electrocatalysis, in particular to a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, a preparation method and an application thereof.

Background technique

Energy and environmental issues have prompted people to demand a renewable clean energy technology. As a renewable clean energy with high energy density, hydrogen energy has broad application prospects.

Electrocatalytic water splitting for hydrogen production is an effective technology for obtaining hydrogen energy. However, the oxygen evolution half-reaction (OER) involves the transfer process of four electrons, and the reaction process is slow, which restricts the efficiency of water electrolysis for hydrogen production. The catalytic efficiency of reactive electrocatalysts is the key to realizing efficient water electrolysis for hydrogen production.

At present, most commercial oxygen evolution electrocatalysts are ruthenium dioxide and iridium dioxide based on precious metals. However, they are expensive and the earth's reserves are scarce. Therefore, it is necessary to develop and design non-precious metal-based oxygen evolution electrocatalysts to meet the large-scale industrialization of hydrogen production by electrolysis of water. Application requirements.

In view of the above-mentioned defects, the creator of the present invention finally obtained the present invention after a long period of research and practice.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of poor oxygen evolution performance and stability of the existing electrocatalyst, and provides a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, a preparation method and an application thereof.

In order to achieve the above purpose, the present invention discloses a preparation method of a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, comprising the following steps:

S1: Weigh nickel nitrate, cerium nitrate and sodium thiosulfate respectively;

S2: adding the precursor reagent weighed in step S1 into a reactor containing deionized water and a substrate, and heating;

S3: After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

In the step S1, the mass of nickel nitrate is 45-360 mg, the mass of cerium nitrate is 20-180 mg, and the mass of sodium thiosulfate is 10-60 mg.

In the step S2, deionized water is 60 mL.

In the step S2, the heating temperature is 120°C, and the heating is maintained for 12 hours.

In the step S2, the substrate is any one of foamed nickel, foamed iron, carbon cloth and conductive glass.

The invention also discloses the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst prepared by the above preparation method and the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst in electrocatalysis Application of Moisture Analysis Oxygen.

Compared with the prior art, the beneficial effects of the present invention are: the present invention uses nickel nitrate, cerium nitrate and sodium thiosulfate as raw materials, and grows sulfur-doped nickel hydroxide-dihydroxide-dioxide in situ on the foam nickel substrate by a one-step hydrothermal method. Cerium oxide composite nanorod arrays. The electrocatalyst of the invention has a simple preparation process, and simultaneously exhibits excellent electrocatalytic activity and stability for the electrocatalytic water desorption oxygen reaction;

The sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst prepared by the invention has excellent catalytic performance when applied to electrocatalytic oxygen evolution reaction, and only needs 200mV overpotential when the current density is 10mA/ ^cm2 . 10mA/cm ² , 20mA/cm ² , 50mA/cm ² , 100mA/cm ² , 300mA/cm ² , 10mA were applied to the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst prepared by the method of the present invention, respectively The electrocatalytic oxygen evolution performance of the electrocatalyst remains stable at a current of 25 hours per cm ² . Therefore, the electrocatalyst of the present invention has excellent electrocatalytic activity and stability for the water decomposition oxygen reaction, and meets the requirements of large-scale industrial application.

Description of drawings

1 is a SEM image of the sulfur-doped nickel hydroxide-ceria composite nanorod array prepared in Example 3;

2 is the XRD pattern of the sulfur-doped nickel hydroxide-ceria composite nanorod array prepared in Example 3;

Fig. 3 is the linear sweep voltammetry curve of the sample electrocatalytic oxygen evolution reaction prepared by different embodiments;

4 is the linear sweep voltammetry curve of the oxygen evolution reaction of the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst prepared in Example 3, the electrocatalyst composited with undoped S and CeO ₂ and commercial RuO ₂ ;

Figure 5 is a graph showing the overpotentials of sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalysts at different current densities;

Figure 6 shows the stability test results of the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst.

Detailed ways

The above and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings.

Example 1

This embodiment provides a method for preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, including the following steps:

(1) Weigh an appropriate amount of 180 mg of nickel nitrate and 40 mg of sodium thiosulfate respectively.

(2) The above precursor reagents were placed in a 100 mL reaction kettle containing 60 mL of deionized water and nickel foam.

(3) The reaction kettle was heated to 120°C and kept for 12h.

(4) After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

Example 2

This embodiment provides a method for preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, including the following steps:

(1) Weigh an appropriate amount of 180mg nickel nitrate, 45mg cerium nitrate and 40mg sodium thiosulfate respectively.

(2) The above precursor reagents were placed in a 100 mL reaction kettle containing 60 mL of deionized water and nickel foam.

(3) The reaction kettle was heated to 120°C and kept for 12h.

(4) After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

Example 3

This embodiment provides a method for preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, including the following steps:

(1) Weigh an appropriate amount of 180mg nickel nitrate, 90mg cerium nitrate and 40mg sodium thiosulfate respectively.

(2) The above precursor reagents were placed in a 100 mL reaction kettle containing 60 mL of deionized water and nickel foam.

(3) The reaction kettle was heated to 120°C and kept for 12h.

(4) After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

Example 4

This embodiment provides a method for preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, including the following steps:

(1) Weigh an appropriate amount of 180mg nickel nitrate, 180mg cerium nitrate and 40mg sodium thiosulfate respectively.

(2) The above precursor reagents were placed in a 100 mL reaction kettle containing 60 mL of deionized water and nickel foam.

(3) The reaction kettle was heated to 120°C and kept for 12h.

(4) After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

Example 5

This embodiment provides a method for preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst, including the following steps:

(1) Weigh an appropriate amount of 180mg nickel nitrate, 360mg cerium nitrate and 40mg sodium thiosulfate respectively.

(2) The above precursor reagents were placed in a 100 mL reaction kettle containing 60 mL of deionized water and nickel foam.

(3) The reaction kettle was heated to 120°C and kept for 12h.

(4) After cooling to room temperature, the foamed nickel is removed, and after washing and drying, a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst is obtained.

From the SEM image of the sulfur-doped nickel hydroxide-ceria composite nano-electrocatalyst prepared in Example 3 in Fig. 1, it can be seen that it is a nanorod array structure, and it can be seen from its XRD diagram that its phase composition is nickel hydroxide and ceria.

The electrocatalytic oxygen evolution polarization of nickel foam self-supporting sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst (S-Ni(OH) ₂ /CeO ₂ /NF) prepared in different examples was tested curves to compare its ability to electrocatalytically split water for oxygen evolution with undoped and uncomplexed nickel hydroxide and commercial _RuO2 . The specific process is as follows:

The electrocatalysts prepared in different examples were used as the working electrode, the platinum sheet electrode was used as the counter electrode, the Hg/HgO electrode was used as the reference electrode, and the freshly prepared 1M KOH aqueous solution (PH=13.9) was used as the electrolyte to test the electrocatalysis. Oxygen evolution reaction polarization curve (Fig. 3). It can be seen from Figure 3 that when the amount of cerium nitrate is 90 mg, the electrocatalytic performance of the obtained catalyst is the best.

Ni(OH) ₂ /NF, S-Ni(OH) ₂ /NF, S-Ni(OH) ₂ /CeO ₂ /NF, RuO ₂ /NF were used as working electrodes, and platinum sheet electrodes were used as counter electrodes. The Hg/HgO electrode was used as the reference electrode, and a freshly prepared 1M KOH aqueous solution (PH=13.9) was used as the electrolyte to test the polarization curve of the electrocatalytic oxygen evolution reaction (Fig. 4). _Comparing ^the _{overpotentials ( _ _} Figure 5), it can be seen that the S-Ni(OH) ₂ /CeO ₂ /NF nanorod array structure only needs an overpotential of 200mV at a current density of 10mA/cm ² , and its performance is far superior to that of undoped and uncomplexed Catalyst and electrocatalytic performance of commercial _RuO .

10mA/cm ² , 20mA/cm ² , 50mA/cm ² , 100mA/cm ² , 300mA/cm ² , 10mA/cm ² currents were continuously applied to the S-Ni(OH) ₂ /CeO ₂ /NF nanorod array structure. 25h, the electrocatalytic stability was tested, and the results are shown in Figure 6. The results show that the electrocatalytic oxygen evolution performance of the S-Ni(OH) ₂ /CeO ₂ /NF nanorod array remains stable after 150h of testing, which is suitable for industrial application.

The above descriptions are only preferred embodiments of the present invention, which are merely illustrative rather than limiting for the present invention. Those skilled in the art understand that many changes, modifications and even equivalents can be made within the spirit and scope defined by the claims of the present invention, but all fall within the protection scope of the present invention.

Claims (7)

1. A preparation method of a sulfur-doped nickel hydroxide-cerium dioxide composite nanorod array electrocatalyst is characterized by comprising the following steps of:

s1: respectively weighing nickel nitrate, cerium nitrate and sodium thiosulfate;

s2: adding the precursor reagent weighed in the step S1 into a reaction kettle containing deionized water and a substrate, and heating;

s3: and cooling to room temperature, removing the foamed nickel, washing and airing to obtain the sulfur-doped nickel hydroxide-cerium dioxide composite nanorod array electrocatalyst.

2. The method of claim 1, wherein in step S1, the mass of nickel nitrate is 45-360 mg, the mass of cerium nitrate is 20-180 mg, and the mass of sodium thiosulfate is 10-60 mg.

3. The method of claim 1, wherein the deionized water in the step S2 is 60 mL.

4. The method of claim 1, wherein the heating temperature of step S2 is 120 ℃, and the heating time is 12 hours after heating.

5. The method of preparing a sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst according to claim 1, wherein the substrate in step S2 is any one of nickel foam, iron foam, carbon cloth, and conductive glass.

6. The sulfur-doped nickel hydroxide-cerium dioxide composite nanorod array electrocatalyst prepared by the preparation method of any one of claims 1 to 5.

7. Use of the sulfur-doped nickel hydroxide-ceria composite nanorod array electrocatalyst according to claim 6 for electrocatalytic water decomposition of oxygen.

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