Preparation and Electrocatalytic Hydrogen Evolution Performance of CoS₂:Mo Microrods

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Cobalt disulfide (CoS₂) is a promising non-precious metal catalyst for hydrogen evolution.
• Developing efficient and cost-effective electrocatalysts is crucial for energy applications.

Purpose of the Study:

• To synthesize and characterize molybdenum-doped cobalt disulfide (CoS₂:Mo) via a hydrothermal method.
• To evaluate the electrocatalytic performance of CoS₂:Mo for hydrogen evolution in alkaline media.

Main Methods:

• Hydrothermal synthesis of CoS₂:Mo.
• X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Energy-Dispersive X-ray Spectroscopy (EDS) for material characterization.
• Electrochemical measurements including overpotential, Tafel slope, and double-layer capacitance (C_dl).

Main Results:

• CoS₂:Mo crystallizes in a cubic pyrite structure with microrod morphology.
• Mo is uniformly doped into the CoS₂ lattice, enhancing conductivity and active sites.
• CoS₂:Mo exhibits a low overpotential (122 mV) and Tafel slope (128 mV dec^-1), outperforming pure CoS₂ and MoS₂.
• Enhanced double-layer capacitance (C_dl = 2.72 mF cm^-2) for CoS₂:Mo compared to CoS₂ (1.63 mF cm^-2) and MoS₂ (0.31 mF cm^-2).

Conclusions:

• Molybdenum doping is an effective strategy to enhance the electrocatalytic activity of cobalt disulfide for hydrogen evolution.
• CoS₂:Mo demonstrates superior performance compared to pure CoS₂ and MoS₂, making it a promising non-precious metal electrocatalyst.
• This research offers a viable approach for developing cost-efficient, high-performance electrocatalysts for hydrogen production.