Self-assembled Co_0.85Se/carbon nanowires as a highly effective and stable electrocatalyst for the hydrogen evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) is crucial for clean energy technologies.
• Transition metal selenides are promising HER electrocatalysts but often suffer from aggregation and poor conductivity.

Purpose of the Study:

• To synthesize and characterize a novel self-assembled Co_0.85Se/carbon nanowire (Co_0.85Se@CNW) hybrid material.
• To evaluate the electrocatalytic performance of the Co_0.85Se@CNW hybrid for the HER.
• To elucidate the structure-property relationship contributing to the enhanced HER activity.

Main Methods:

• Facile solvothermal reaction and selenylation process for synthesizing Co_0.85Se@CNW hybrids.
• Electrochemical characterization including cyclic voltammetry and chronoamperometry to assess HER performance.
• Analysis of Tafel slope, onset potential, and cycling stability.

Main Results:

• The Co_0.85Se@CNW hybrid exhibited excellent HER activity with a low onset potential of 138 mV vs. RHE.
• A small Tafel slope of 43.4 mV dec^-1 indicates efficient charge transfer kinetics.
• The hybrid demonstrated remarkable stability, retaining over 95% of its current after 1500 cycles.

Conclusions:

• The unique particle-in-nanowire architecture of Co_0.85Se@CNWs effectively prevents nanoparticle aggregation and enhances charge transfer.
• The Co_0.85Se@CNW hybrid serves as a highly effective and stable electrocatalyst for the HER.
• This work presents a new strategy for designing transition metal-based selenide hybrids for advanced electrocatalytic applications.