Cytosine-Co assemblies derived CoN_x rich Co-NCNT as efficient tri-functional electrocatalyst

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Carbon-metal composites are promising for catalysis but challenging to synthesize with controlled structures and strong interactions.
• Developing multifunctional electrocatalysts is crucial for energy conversion technologies.

Purpose of the Study:

• To present a novel gas-foaming assembly strategy for preparing tunable carbon-metal composites.
• To investigate the structure-property relationships of cobalt and nitrogen-codoped carbon nanotubes (Co-NCNTs) as electrocatalysts.

Main Methods:

• A unique gas-foaming assembly strategy using cytosine-Co chelate was employed.
• The structure of Co-NCNTs was controlled by adjusting cytosine-Co coordination and carbonization temperature.
• Electrochemical performance was evaluated for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER).

Main Results:

• The optimal Co-NCNT featured homogeneous NCNTs, CoO_x, and CoN_x moieties with a mesoporous nanosheet architecture.
• Co-NCNT demonstrated remarkable ORR onset potential (0.93 V in 0.1 M KOH) and significant OER/HER activity.
• Cobalt-nitrogen (CoN_x) moieties were identified as the key active sites responsible for the enhanced electrocatalytic activity.

Conclusions:

• The gas-foaming assembly strategy provides a pathway for designing advanced multifunctional electrocatalysts with tunable structures.
• CoN_x moieties play a critical role in enhancing metal-carbon synergy, reducing resistance, and improving the stability of the composite electrocatalysts.
• This work offers insights into the rational design of high-performance multifunctional electrocatalysts for energy applications.