Zeolitic Imidazolate Framework-Derived Co₃S₄@NiFe-LDH Core-Shell Heterostructure as Efficient Bifunctional...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for sustainable hydrogen production via water splitting.
• Developing bifunctional catalysts that perform both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is a key challenge.

Purpose of the Study:

• To synthesize and characterize a novel Co3S4@NiFe-LDH core-shell heterostructure for overall water splitting.
• To investigate the electrocatalytic performance and stability of the synthesized material for OER and HER.

Main Methods:

• Electrodeposition of ultrathin NiFe-LDH nanosheets on Co3S4 nanosheet arrays derived from zeolitic imidazolium frameworks.
• Electrochemical testing in 1 M KOH for OER and HER performance evaluation.
• Density Functional Theory (DFT) calculations to understand interfacial electronic interactions.

Main Results:

• The Co3S4@NiFe-LDH/NF exhibited low overpotentials for OER (235 mV at 100 mA cm-2) and HER (95 mV at 10 mA cm-2).
• An assembled overall water splitting cell using the catalyst showed low voltages (1.595 V at 10 mA cm-2) and remarkable stability (>500 h).
• DFT calculations revealed strong electron interaction at the interface, facilitating electron transfer and reducing OER energy barriers.

Conclusions:

• The Co3S4@NiFe-LDH core-shell heterostructure is a highly promising bifunctional electrocatalyst for efficient and stable overall water splitting.
• Constructing heterojunction interfaces is an effective strategy for designing advanced electrocatalysts.
• The synergistic electronic effects at the interface significantly enhance catalytic activity.