Interface Enables Faster Surface Reconstruction in a Heterostructured CuSe/NiSe Electrocatalyst for Realizing Urea...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient and affordable electrocatalysts is essential for advancing urea-based technologies.
• Understanding the real-time catalytic mechanisms of the urea oxidation reaction (UOR) is critical for optimizing performance.

Purpose of the Study:

• To synthesize and characterize a novel Cu-Ni based selenide electrocatalyst (CuSe/NiSe/NF) for the urea oxidation reaction.
• To investigate the catalytic performance, stability, and reaction mechanism of the synthesized electrocatalyst.
• To elucidate the role of the heterogeneous interface and synergistic effects between CuSe and NiSe in enhancing UOR.

Main Methods:

• Hydrothermal synthesis and selenization treatment were employed to create the CuSe/NiSe/NF electrocatalyst.
• In-situ Raman spectroscopy and ex-situ characterizations (e.g., XPS) were used to study the catalyst's structural and chemical evolution during UOR.
• Electrochemical techniques, including cyclic voltammetry and chronoamperometry, were utilized to evaluate the electrocatalytic performance and stability.

Main Results:

• The CuSe/NiSe/NF electrocatalyst exhibited outstanding UOR performance, achieving 10 mA cm⁻² at 1.31 V and maintaining stability for 96 hours.
• In-situ Raman spectroscopy revealed the formation of NiOOH through surface reconstruction, with high-valence Ni identified as the active site for UOR.
• Electrochemical analysis and XPS studies demonstrated that electron transfer from CuSe to NiSe enhances UOR kinetics and that CuSe facilitates NiSe surface reconstruction, creating more active sites.

Conclusions:

• The Cu-Ni based selenide electrocatalyst (CuSe/NiSe/NF) serves as an effective "precatalyst" for highly efficient UOR.
• The study provides a deep understanding of the mechanism behind electrocatalyst structural changes and identifies the true active sites during UOR.
• Synergistic effects between CuSe and NiSe, including electron transfer and facilitated surface reconstruction, are key to the enhanced UOR performance.