N-Doped amorphous MoS_x for the hydrogen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Crystalline MoS₂ (c-MoS₂) doping with nitrogen (N) for hydrogen evolution reaction (HER) is known.
• Amorphous MoS_x (a-MoS_x) is a more active HER catalyst, but N-doping effects are unexplored.

Purpose of the Study:

• To fabricate N-doped a-MoS_x for the first time.
• To investigate the role of N dopants in a-MoS_x for HER performance.

Main Methods:

• Simple fabrication method for N-doped a-MoS_x.
• X-ray photoelectron spectroscopy (XPS) for material characterization.
• First-principles calculations for theoretical analysis.

Main Results:

• N doping in basal plane S^2- sites is crucial for HER enhancement and stability.
• N-doped a-MoS_x shows increased active sites and improved conductivity.
• Calculations confirm improved hydrogen adsorption free energy at unsaturated Mo^V sites.

Conclusions:

• N-doped a-MoS_x is a highly effective HER catalyst.
• N doping in basal plane S^2- sites is key to improved HER activity.
• This work offers insights for developing nonmetal-doped MoS_x catalysts for HER.