Hydrogen evolution boosted by moderate Co₃ZnC with current densities beyond 1000 mA cm^-2

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for hydrogen evolution is crucial for renewable energy technologies.
• Co@N,O co-doped carbons show promise but require further optimization for enhanced activity.

Purpose of the Study:

• To investigate the role of Cobalt Zinc Carbide (Co3ZnC) in boosting the catalytic activity of Co@N,O co-doped carbons for hydrogen evolution.
• To understand the structure-activity relationship influenced by moderate Co3ZnC content.

Main Methods:

• Electrochemical synthesis and characterization of Co@N,O co-doped carbon materials with varying Co3ZnC content.
• Hydrogen evolution reaction (HER) performance testing using techniques like cyclic voltammetry and linear sweep voltammetry.
• Analysis of electronic structure and surface properties using X-ray photoelectron spectroscopy (XPS) and electrochemical surface area (ECSA) measurements.

Main Results:

• Moderate Co3ZnC content was found to be critical for optimizing the catalytic performance.
• Co3ZnC facilitates an appropriate weighted Co 3d band center, enhancing charge transfer kinetics.
• The optimized catalyst achieved a low overpotential of approximately 219 mV to drive a high current density of 1000 mA cm-2.

Conclusions:

• Co3ZnC acts as a key promoter in Co@N,O co-doped carbon electrocatalysts for hydrogen evolution.
• The presence of moderate Co3ZnC significantly enhances charge transfer and electrochemical active surface area, leading to superior catalytic efficiency.
• This study highlights a promising strategy for designing advanced electrocatalysts for efficient hydrogen production.