2D Cobalt Chalcogenide Heteronanostructures Enable Efficient Alkaline Hydrogen Evolution Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High-efficiency non-precious metal electrocatalysts are vital for alkaline electrolyte hydrogen evolution reactions (HER) to address fossil fuel limitations and carbon emissions.
• Developing advanced catalysts is key for sustainable energy conversion technologies.

Purpose of the Study:

• To present a highly active electrocatalyst for hydrogen production using 2D CoSe2/Co3S4 heterostructured nanosheets along Co3O4 nanofibers.
• To investigate the roles of different compositions within the heterojunction for optimized HER performance.

Main Methods:

• Fabrication of 2D CoSe2/Co3S4 heterostructured nanosheets on Co3O4 nanofibers.
• Characterization of the 2D/1D heteronanostructures to analyze electrochemical active area, active sites, and hydrogen binding energy.
• Electrochemical testing in 1 m KOH electrolyte to evaluate overpotential, stability, and Faradaic efficiency for HER.

Main Results:

• The 2D/1D heteronanostructures significantly improved electrochemical active area, active sites, and hydrogen binding energy compared to individual cobalt chalcogenides.
• The CoSe2/Co3S4@Co3O4 catalyst demonstrated low overpotentials of 165 mV for 10 mA cm−2 and 393 mV for 200 mA cm−2.
• The catalyst exhibited excellent long-term stability over 55 hours of operation with near 100% Faradaic efficiency for hydrogen production.

Conclusions:

• The developed CoSe2/Co3S4@Co3O4 heterostructure serves as a highly efficient electrocatalyst for alkaline HER.
• This work offers a new design strategy for Co-based catalysts for efficient hydrogen production, contributing to sustainable energy solutions.