Development of Cu₃N electrocatalyst for hydrogen evolution reaction in alkaline medium

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalysts are crucial for efficient hydrogen evolution reaction (HER).
• Developing cost-effective and high-performance electrocatalysts remains a significant challenge.
• Copper-based materials offer potential due to their abundance and tunable properties.

Purpose of the Study:

• To synthesize copper nitride (Cu3N) via nitridation of copper(II) oxide (Cu2O).
• To evaluate Cu3N as a novel electrocatalyst for HER in an alkaline medium.
• To investigate the electrochemical performance and reaction kinetics of Cu3N for HER.

Main Methods:

• Synthesis of Cu3N by nitridation of Cu2O.
• Electrochemical testing including overpotential and Tafel slope measurements.
• Electrochemical impedance spectroscopy (EIS) to determine charge transfer resistance.
• Analysis of reaction kinetics, identifying the Volmer-Heyrovsky mechanism.

Main Results:

• Cu3N exhibited a low overpotential of 149.18 mV and a Tafel slope of 63.28 mV/dec at 10 mA/cm².
• Electrochemical impedance spectroscopy revealed a low charge transfer resistance of 1.44 Ω.
• Enhanced electron transfer rates and accessible active sites were observed due to Cu3N's structure and conductivity.
• The HER kinetics were governed by the Volmer-Heyrovsky mechanism.

Conclusions:

• Cu3N is a promising, low-cost electrocatalyst for HER with excellent electrochemical performance.
• The synthesis method and structural properties of Cu3N contribute to its enhanced catalytic activity.
• This work presents a new pathway for developing efficient electrocatalysts for energy conversion and storage applications.