Zn-Doped CoS₂ Nanoarrays for an Efficient Oxygen Evolution Reaction: Understanding the Doping Effect for a...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is critical for energy conversion and storage.
• Low-cost, durable, and highly active catalysts are needed to advance technologies like water splitting and metal-air batteries.

Purpose of the Study:

• To synthesize and characterize a novel Zn-doped CoS2 nanoarray catalyst supported on carbon cloth (Co(Zn)S2/CC).
• To evaluate the electrocatalytic performance and durability of the Co(Zn)S2/CC for the OER.
• To investigate the mechanism of OER and the role of Zn doping.

Main Methods:

• Facile sulfidization of CoZn metal-organic frameworks to form Co(Zn)S2 nanoarrays on carbon cloth.
• Electrochemical testing in 1 M KOH to assess OER activity and durability.
• X-ray photoelectron spectroscopy (XPS) and *in situ* Raman spectroscopy to study surface reconstruction and electronic structure.

Main Results:

• The Co(Zn)S2/CC catalyst exhibited excellent OER activity with a low overpotential (η = 248 mV at 10 mA/cm2).
• The catalyst demonstrated long-term durability under OER conditions.
• Spectroscopic studies revealed surface reconstruction to Co(Zn)OOH with adsorbed SO4(2-) and indicated that Zn doping modifies the electronic structure of Co species.

Conclusions:

• Zn-doped CoS2 nanoarrays on carbon cloth are effective electrocatalysts for the OER.
• The study provides insights into the doping effect of Zn on the OER performance of transition metal sulfides.
• The facile synthesis method offers a new route for preparing bimetallic sulfides for energy applications.