Core-Shell CoS₂@MoS₂ with Hollow Heterostructure as an Efficient Electrocatalyst for Boosting Oxygen Evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts are crucial for electrochemical water splitting.
• Developing advanced electrocatalysts reduces energy barriers for water decomposition.

Purpose of the Study:

• To synthesize and evaluate a core-shell electrocatalyst for the oxygen evolution reaction (OER).
• To investigate the structural and chemical properties of the CoS₂@MoS₂ heterostructure for enhanced catalytic activity.

Main Methods:

• Synthesis of a core-shell structure using cobalt sulfides (CoS₂) as the core and molybdenum disulfide (MoS₂) nanosheets as the shell.
• Characterization of the CoS₂@MoS₂ heterostructure and evaluation of its electrocatalytic performance in an alkaline electrolyte.

Main Results:

• The CoS₂@MoS₂ core-shell catalyst demonstrated excellent OER performance, requiring only 254 mV overpotential for 10 mA cm^-2.
• The catalyst exhibited a low Tafel slope (86.9 mV dec^-1) and low charge transfer resistance (47 Ω), indicating fast reaction kinetics.
• Exceptional stability was confirmed through 1000 cycles of cyclic voltammetry and a 10-hour chronoamperometry test.

Conclusions:

• The core-shell structure effectively prevents MoS₂ agglomeration, exposes active sites, and improves ion diffusion.
• The formation of the CoS₂/MoS₂ heterostructure enhances catalytic activity and stability for the OER.
• This study provides a design strategy for developing efficient core-shell heterostructure catalysts for OER.