Carbon-Encapsulated Nickel via Cellulose Acetate Coordination for Efficient Hydrogen Evolution Reactions

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Efficient and stable electrocatalysts are crucial for sustainable green hydrogen production via hydrogen evolution reactions (HERs).
• Carbon-coated metal materials show promise for HERs due to their conductivity, stability, and catalytic sites, but synthesis can be costly and yield non-uniform coatings.
• Challenges exist in developing affordable and uniform carbon-coated electrocatalysts for large-scale hydrogen production.

Purpose of the Study:

• To develop a straightforward and cost-effective method for synthesizing self-supported carbon-coated nickel nanoparticle electrocatalysts.
• To investigate the hydrogen evolution reaction (HER) performance of the synthesized electrocatalyst in an alkaline electrolyte.
• To demonstrate the potential industrial applicability of the developed electrocatalyst for green hydrogen production.

Main Methods:

• A synergistic chelation effect between cellulose acetate and cotton fabric was used to coordinate nickel ions.
• Self-supported carbon-coated nickel nanoparticle (CF-C/Ni_x-y) electrocatalysts were synthesized via a one-step pyrolysis process.
• Electrocatalytic HER performance was evaluated in a 1 M KOH electrolyte, including overpotential, Tafel slope, and long-term stability tests.

Main Results:

• The CF-C/Ni₂-900 electrocatalyst, pyrolyzed at 900 °C, demonstrated optimal HER performance.
• An overpotential of 292 mV at 100 mA cm^-2 and a Tafel slope of 126.4 mV dec^-1 were achieved.
• Sustained high activity was observed for 50 hours at 100 mA cm^-2, indicating excellent stability.

Conclusions:

• A rational and feasible strategy for designing self-supported carbon-coated nickel nanoparticle electrocatalysts was proposed.
• The developed CF-C/Ni₂-900 electrocatalyst exhibits promising performance for hydrogen evolution reactions.
• The findings offer valuable insights for the industrial application of these electrocatalysts in hydrogen production.