New Simultaneous Exfoliation and Doping Process for Generating MX₂ Nanosheets for Electrocatalytic Hydrogen Evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nonmetal atom doping in transition metal dichalcogenides (MX2) enhances catalytic activity for hydrogen evolution.
• Developing efficient and scalable methods for producing doped MX2 nanosheets is crucial.

Purpose of the Study:

• To develop a novel, one-step plasma-induced doping and exfoliation method for MX2 materials.
• To investigate the catalytic performance of nitrogen-doped Molybdenum Disulfide (N-doped MoS2) nanosheets for the hydrogen evolution reaction (HER).

Main Methods:

• A one-step plasma-induced doping and exfoliation technique at low temperature (ca. 80 °C).
• Utilizing active plasma generated by an asymmetric electrical field during electrochemical reaction.
• Doping nitrogen atoms from electrolytes into MX2 structures (MoSe2, WSe2, MoS2, WS2) during exfoliation.

Main Results:

• Achieved simultaneous doping and exfoliation of MX2 bulk into nanosheets.
• N-doped MoS2 nanosheets with 5.2 atom % nitrogen showed excellent HER catalytic activity.
• Demonstrated a low overpotential (164 mV at 10 mA cm-2) and Tafel slope (71 mV dec-1) for N-doped MoS2.
• Exhibited extraordinary long-term stability (>25 h) in 0.5 M H2SO4.

Conclusions:

• The developed plasma-assisted method efficiently produces N-doped MX2 nanosheets with enhanced HER performance.
• Synergistic effects of nitrogen doping and nanosheet structure significantly improve electronic and transport properties for catalysis.
• N-doped MoS2 nanosheets represent a promising electrocatalyst for efficient and stable hydrogen production.