Cu- and S-Doped Heteropolyacid Co₂Mo₁₀ as Electrocatalysts for Efficient Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts is crucial for hydrogen evolution reactions (HER).
• Polyoxometalate precursors offer versatile routes for novel material synthesis.
• Controlling material morphology impacts catalytic performance.

Purpose of the Study:

• To synthesize and characterize carbon cloth-supported Cu$_{}$S-CoS$_{2}$-MoS$_{2}$ nanomaterials.
• To investigate the effect of reducing gas atmosphere during synthesis on material morphology and catalytic activity.
• To evaluate the electrocatalytic performance of the synthesized materials for HER.

Main Methods:

• Two-step synthesis using polyoxometalate Co$_{2}$Mo$_{10}$ precursor.
• Characterization via X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM).
• Electrochemical testing for hydrogen evolution reaction (HER) in alkaline and acidic media.

Main Results:

• Calcination atmosphere (NH$_{3}$ vs. H$_{2}$-Ar) significantly altered material morphology and catalytic activity.
• Cu$_{}$S-CoS$_{2}$-MoS$_{2}$ synthesized under NH$_{3}$ exhibited enhanced HER activity (overpotentials of 108 mV in alkaline, 196 mV in acidic at 10 mA cm$^{-2}$).
• The NH$_{3}$-derived materials demonstrated excellent long-term durability.

Conclusions:

• Ammonia atmosphere during calcination is key to achieving optimal morphology and enhanced HER performance.
• The synthesized Cu$_{}$S-CoS$_{2}$-MoS$_{2}$ nanomaterials represent promising electrocatalysts for efficient hydrogen production.
• This work provides a method for designing multicomponent electrocatalysts with tunable properties.