Utilizing ion leaching effects for achieving high oxygen-evolving performance on hybrid nanocomposite with...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ion leaching is a common issue in pure-phase oxygen-evolving electrocatalysts, leading to structural collapse.
• Perovskite catalysts are promising for oxygen evolution reactions but suffer from instability.

Purpose of the Study:

• To develop a novel strategy to mitigate ion leaching and enhance the stability of perovskite electrocatalysts.
• To investigate the effect of introducing soluble salts on the crystalline structure and catalytic performance.

Main Methods:

• A self-assembly process was employed to introduce soluble BaCl2 and SrCl2 into perovskite structures.
• Operando spectroscopic techniques were used to analyze the catalyst structure and ion leaching behavior.
• Electrochemical performance was evaluated by measuring overpotential at a specific current density.

Main Results:

• The self-assembled hybrid Ba0.35Sr0.65Co0.8Fe0.2O3-δ (BSCF) nanocomposite demonstrated a low overpotential of 260 mV at 10 mA cm⁻².
• Pre-leaching of soluble compounds facilitated the formation of stable surface structures with edge/face-sharing.
• The optimized structures exhibited stable lattice oxygen active sites and facilitated OH⁻ adsorption.

Conclusions:

• Introducing soluble salts via self-assembly is an effective strategy to protect the perovskite crystalline matrix from ion leaching.
• The hybrid BSCF nanocomposite shows enhanced stability and catalytic activity for oxygen evolution reactions.
• The study provides insights into designing robust perovskite electrocatalysts by controlling interfacial ion concentrations.