Electrocatalyst with cobalt-based multi-stage nano-composite structure for oxygen production by electrolysis of water and preparation method of electrocatalyst

Abstract

The invention provides an electrocatalyst with a cobalt-based multi-stage nano-composite structure for oxygen production by electrolysis of water and a preparation method of the electrocatalyst. The preparation method comprises the following steps: dissolving cobalt nitrate hexahydrate, urea and ammonium fluoride in deionized water to obtain a precursor solution; transferring the precursor solution into a hydrothermal reactor; adding carbon fiber paper; enabling basic cobalt carbonate nanowires to grow on the carbon fiber paper through solvothermal reaction; after finish of reaction, naturally cooling; then taking out a product; washing and drying to obtain a carbon fiver paper loaded basic cobalt carbonate nanowire composite structure; by taking powdered sulfur as the raw material, preparing a carbon fiber paper loaded cobalt sulfide nanowire composite structure through low-temperature sulfuration reaction under the condition of an inert gas; and finally, electroplating the surface of the carbon fiber paper loaded cobalt sulfide nanowire composite structure with a layer of cobalt hydroxide nanosheets by use of the electrochemical deposition method so as to obtain the electrocatalyst with the cobalt-based multi-stage nano-composite structure for oxygen production by electrolysis of water. As the sulfide and the hydroxide of transition metal cobalt are adopted as the catalyst, in comparison with noble metals, the cost of the catalyst is lowered.

Description

technical field

[0001] The invention relates to a cobalt-based multilevel nanocomposite structure electrolyzed water oxygen production electrocatalyst and a preparation method thereof, belonging to the field of energy and catalytic materials. Background technique

[0002] The sustainable development of human beings is facing severe energy crisis and environmental pollution problems. The production of hydrogen and oxygen by photo- or electrolysis of water is an effective way to solve the current crisis. However, in the process of electrocatalytic water splitting, the kinetic hindrance of the oxygen evolution reaction seriously restricts the improvement of water splitting efficiency, so finding an efficient oxygen evolution electrocatalyst becomes the key to improving the efficiency. At present, noble metal oxides such as iridium dioxide, ruthenium dioxide, and platinum dioxide are recognized as the most efficient electrocatalysts for oxygen evolution. However, these noble met...

Examples

Embodiment 1

[0030] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 7 hours, cool it naturally, take it out, wash it, and dry it to get the composite structure of basic cobalt carbonate nanowires loaded on carbon fiber paper.

[0031] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0032] Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure as the working electrode, platinum as the auxi...

Embodiment 2

[0034] The difference from Example 1 is:

[0035] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 10 hours, cool it naturally, take it out, wash it, and dry it to get a carbon fiber paper-loaded basic cobalt carbonate nanowire composite structure.

[0036] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0037] Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure as the wor...

Embodiment 3

[0039] The difference from Example 1 is:

[0040] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 12 hours, cool it naturally, take it out, wash it, and dry it to get the carbon fiber paper-loaded basic cobalt carbonate nanowire composite structure.

[0041] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0042]Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure rice wire...

technical field

[0001] The invention relates to a cobalt-based multilevel nanocomposite structure electrolyzed water oxygen production electrocatalyst and a preparation method thereof, belonging to the field of energy and catalytic materials. Background technique

[0002] The sustainable development of human beings is facing severe energy crisis and environmental pollution problems. The production of hydrogen and oxygen by photo- or electrolysis of water is an effective way to solve the current crisis. However, in the process of electrocatalytic water splitting, the kinetic hindrance of the oxygen evolution reaction seriously restricts the improvement of water splitting efficiency, so finding an efficient oxygen evolution electrocatalyst becomes the key to improving the efficiency. At present, noble metal oxides such as iridium dioxide, ruthenium dioxide, and platinum dioxide are recognized as the most efficient electrocatalysts for oxygen evolution. However, these noble met...

Examples

Embodiment 1

[0030] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 7 hours, cool it naturally, take it out, wash it, and dry it to get the composite structure of basic cobalt carbonate nanowires loaded on carbon fiber paper.

[0031] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0032] Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure as the working electrode, platinum as the auxi...

Embodiment 2

[0034] The difference from Example 1 is:

[0035] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 10 hours, cool it naturally, take it out, wash it, and dry it to get a carbon fiber paper-loaded basic cobalt carbonate nanowire composite structure.

[0036] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0037] Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure as the wor...

Embodiment 3

[0039] The difference from Example 1 is:

[0040] Solvothermal reaction: dissolve 0.87g cobalt nitrate hexahydrate, 0.90g urea, and 0.22g ammonium fluoride in 80mL water, put them into a 100mL hydrothermal kettle, and put washed 2×6cm 2 carbon fiber paper, and then put the hydrothermal kettle into a constant temperature oven at 120°C, keep it warm for 12 hours, cool it naturally, take it out, wash it, and dry it to get the carbon fiber paper-loaded basic cobalt carbonate nanowire composite structure.

[0041] Low-temperature vulcanization reaction: use 2g of sulfur powder as the sulfur source, raise the temperature at 8°C / min to 450°C under nitrogen (flow rate 100sccm), keep it warm for 60min and then cool naturally. The carbon fiber paper supported cobalt sulfide nanowire composite structure was obtained.

[0042]Electrochemical deposition by cyclic voltammetry: using a three-electrode system, carbon fiber paper supported cobalt sulfide nanowire composite structure rice wire...

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