Surface Engineering of Perovskite Oxide LaCo_0.67Cu_0.33O₃ for Improved Overall Water Splitting Activity

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Perovskite oxides exhibit limited electrocatalytic performance for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to low activity, poor conductivity, and few active sites.
• Defect engineering is a key strategy to improve reaction kinetics and catalytic efficiency.

Purpose of the Study:

• To enhance the bifunctional electrocatalytic activity of LaCo_0.67Cu_0.33O₃ (LCCO) perovskite for water splitting through defect engineering.
• To investigate the impact of oxygen defects and surface area on catalytic performance.

Main Methods:

• Synthesis of LCCO perovskite using a sol-gel method.
• Defect engineering via acid etching for varying durations (LCCO-x, x=6, 12, 24, 30 hours).
• Electrocatalytic testing for OER and HER in alkaline media and for overall water splitting.

Main Results:

• LCCO-24 demonstrated significantly enhanced activity and reaction kinetics for both OER and HER.
• The catalyst achieved a low full-cell voltage of 1.49 V at 10 mA·cm^-2 for overall water splitting.
• Enhanced bifunctional activity correlated with increased oxygen defects and surface area.

Conclusions:

• Defect engineering is an effective strategy to boost the electrocatalytic performance of perovskite oxides for water splitting.
• The modified LCCO catalyst shows potential as a cost-effective alternative to noble metal catalysts.