Sulfur Vacancy-Engineered Co₃S₄/MoS₂-Interfaced Nanosheet Array for Enhanced Alkaline Overall Water Splitting

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical water splitting is vital for renewable energy storage.
• Catalyst efficiency and stability are crucial for water splitting.
• Defect and interface engineering enhance electrocatalytic performance.

Purpose of the Study:

• To develop sulfur vacancy-engineered Co3S4/MoS2-interfaced nanosheet arrays.
• To modulate the interface electronic structure for improved catalysis.
• To investigate the electrocatalytic properties for hydrogen and oxygen evolution reactions.

Main Methods:

• Facile synthesis of sulfur vacancy (S_v)-engineered Co3S4/MoS2 nanosheet arrays.
• In situ reduction using sodium borohydride (NaBH4).
• Electrochemical characterization in an alkaline medium.

Main Results:

• S_v-Co3S4/MoS2 demonstrated excellent electrocatalytic activity for HER and OER.
• Low overpotentials of 156 mV (HER) and 209 mV (OER) at 10 mA cm-2 were achieved.
• A low cell voltage of 1.67 V at 10 mA cm-2 for overall water splitting was observed.
• Sustained catalytic activity for over 20 hours confirmed long-term stability.

Conclusions:

• Sulfur vacancy engineering and interface modulation in Co3S4/MoS2 significantly enhance electrocatalytic water splitting.
• The developed catalyst shows bifunctional activity and long-term stability.
• This work presents a novel strategy for creating advanced electrocatalysts for efficient energy storage applications.