Constructing a interfacial electric field for efficient reduction of nitrogen to ammonia

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical nitrogen reduction (eNRR) offers a sustainable route for ammonia synthesis.
• Molybdenum disulfide (MoS2) shows promise as an eNRR electrocatalyst but has limitations in active sites and electron transfer.
• Tin dioxide (SnO2) is an n-type semiconductor with potential applications in catalysis.

Purpose of the Study:

• To enhance the performance of MoS2-based electrocatalysts for eNRR.
• To investigate the effect of a SnO2/MoS2 heterostructure on catalytic activity and selectivity.
• To understand the role of interfacial electric fields in facilitating N2 adsorption and activation.

Main Methods:

• Fabrication of a SnO2/MoS2 heterostructure by depositing SnO2 nanoparticles onto MoS2.
• Characterization of the heterostructure's interfacial properties and electronic structure.
• Theoretical calculations to elucidate the mechanism of N2 adsorption and NN bond activation.
• Electrochemical testing to evaluate ammonia yield and Faraday efficiency.

Main Results:

• The SnO2/MoS2 heterostructure created abundant interfacial contacts and an interfacial electric field.
• Theoretical calculations confirmed the electric field enhances active electrons, N2 adsorption, and NN bond activation.
• The catalyst achieved an ammonia yield of 47.1 µg h⁻¹ mg⁻¹ and a Faraday efficiency of 19.3%.

Conclusions:

• The SnO2/MoS2 heterostructure effectively leverages interfacial electric field effects for improved eNRR.
• This novel catalyst design significantly enhances catalytic activity and selectivity for ammonia production.
• The findings present a promising strategy for developing advanced electrocatalysts for sustainable ammonia synthesis.