Interface engineered Co, Ni, Fe, Cu oxide hybrids with biphasic structures for water splitting with enhanced activity

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient catalysts for water splitting is crucial for clean hydrogen production using renewable energy.
• Metal oxide-based materials are promising candidates for electrocatalytic applications.

Purpose of the Study:

• To rationally design and fabricate a novel metal oxide hybrid catalyst, CoNiFe2O5·2CuO, with unique biphasic microstructures.
• To evaluate the catalyst's performance for electrochemical water splitting, focusing on hydrogen and oxygen evolution reactions.

Main Methods:

• Synthesis of CoNiFe2O5·2CuO metal oxide hybrid catalyst with biphasic microstructures.
• Electrochemical characterization including overpotential measurements for hydrogen and oxygen evolution reactions.
• Fabrication and testing of an electrolyzer cell using the developed catalyst for overall water splitting.

Main Results:

• The CoNiFe2O5·2CuO catalyst exhibited excellent activity for the hydrogen evolution reaction, requiring only a 30 mV overpotential for 10 mA cm⁻².
• It demonstrated a higher turnover frequency (0.3 s⁻¹) than commercial Pt/C (0.1 s⁻¹) at 50 mV overpotential.
• The catalyst also showed good activity for the oxygen evolution reaction with a 264 mV overpotential at 10 mA cm⁻².
• An electrolyzer cell using this catalyst achieved overall water splitting at a low cell voltage of 1.53 V and maintained stability for 100 hours.

Conclusions:

• The biphasic microstructure of CoNiFe2O5·2CuO enhances catalytic activity by creating defects and active sites at interfaces.
• This metal oxide hybrid catalyst presents a promising alternative for efficient and stable electrochemical water splitting.
• The findings suggest significant potential for applications in clean hydrogen production.