Enhanced Electrocatalytic Activity of Amorphized LaCoO₃ for Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Amorphous inorganic perovskites are promising electrocatalysts due to structural flexibility.
• Disordered structures and oxygen vacancies enhance catalytic activity in amorphous oxides.

Purpose of the Study:

• To synthesize and characterize amorphous LaCoO3 for oxygen evolution reaction (OER) electrocatalysis.
• To investigate the effect of amorphization temperature on LaCoO3's catalytic performance.

Main Methods:

• Synthesis of LaCoO3 followed by amorphization via urea reduction.
• Electrochemical testing for OER performance, including overpotential and current density measurements.
• Characterization of catalyst properties such as surface area and Tafel slope.

Main Results:

• Amorphous LaCoO3 synthesized at 450°C (LCO-4) demonstrated exceptional OER activity.
• LCO-4 achieved 10 mA/cm² at 310 mV and 1 A/cm² at 460 mV overpotential.
• LCO-4 exhibited higher electrochemically active surface area, lower Tafel slope (70 mV/dec), and superior long-term stability.

Conclusions:

• Amorphization significantly enhances LaCoO3's OER performance.
• The superior activity of LCO-4 is linked to its disordered structure, small crystallite size, and oxygen vacancies.
• Amorphous LaCoO3 presents a highly efficient and stable electrocatalyst for OER.