Modifying Microenvironment in Van der Waals Gap by Cu/N Co-Doping Strategy for Highly Efficient Nitrite Reduction to...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nitrite electroreduction to ammonia (NO2RR) is crucial for sustainable ammonia synthesis and wastewater remediation.
• Developing highly active and durable electrocatalysts is essential for efficient NO2RR.

Purpose of the Study:

• To design and synthesize a novel sulfur vacancies rich Cu-N co-doped SnS2 nanosheet catalyst for enhanced nitrite electroreduction to ammonia.
• To investigate the catalytic performance, stability, and reaction mechanism of the designed catalyst.

Main Methods:

• Synthesis of Cu-N co-doped SnS2 nanosheets with sulfur vacancies.
• Electrochemical characterization including cyclic voltammetry and chronoamperometry.
• In situ FT-IR and in situ XPS for mechanistic studies.
• Density functional theory (DFT) calculations for theoretical insights.

Main Results:

• The Cu/N-SnS2-x catalyst achieved a high NH3 yield rate of 18.15 mg h-1 mgcat-1 at -0.935 V (vs RHE).
• Excellent Faradaic Efficiency of 95.73% for NH3 was observed at -0.835 V (vs RHE).
• In situ studies and theoretical calculations confirmed enhanced atomic hydrogen generation and efficient nitrite adsorption, facilitating the NO2RR process with structural stability.

Conclusions:

• The Cu-N co-doped SnS2-x nanosheet with sulfur vacancies is a highly active and durable electrocatalyst for nitrite electroreduction to ammonia.
• The synergistic effects of Cu-N doping and sulfur vacancies significantly improve catalytic performance by optimizing electronic structure and intermediate adsorption.
• This work offers new avenues for designing advanced electrocatalysts for ammonia electrosynthesis and environmental applications.