B-doped MoS₂ for nitrate electroreduction to ammonia.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic nitrate-to-ammonia conversion (NO3RR) offers a dual solution for ammonia electrosynthesis and wastewater treatment.
• Developing efficient and selective catalysts is crucial for advancing NO3RR technology.

Purpose of the Study:

• To develop an efficient electrocatalyst for NO3RR using boron-doped molybdenum disulfide (B-MoS2) nanosheet arrays.
• To investigate the catalytic performance and mechanism of B-MoS2 for nitrate reduction.

Main Methods:

• Synthesis of B-MoS2 nanosheet arrays.
• Electrochemical characterization of the catalyst for NO3RR.
• Theoretical computations (e.g., DFT) to elucidate the reaction mechanism and active sites.

Main Results:

• B-MoS2 nanosheet arrays demonstrated high NH3-Faradaic efficiency (92.3%) and NH3 yield (10.8 mg h-1 cm-2) at -0.7 V (RHE).
• Theoretical calculations confirmed that B-dopants are key active sites, enhancing nitrate activation and optimizing reaction intermediates.
• The catalyst exhibited suppressed hydrogen evolution, leading to superior NO3RR selectivity.

Conclusions:

• B-doped MoS2 nanosheet arrays are highly effective electrocatalysts for NO3RR.
• Boron doping significantly enhances catalytic activity and selectivity by optimizing the electronic structure and reaction pathways.
• This work provides a promising pathway for sustainable ammonia production and effective nitrate removal from wastewater.