A cost-effective Co₃O₄@WO₃ hetero-structure derived from WO₃@Co-CoPBA for oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Oxygen evolution reaction (OER) catalysts face challenges like sluggish kinetics, high cost, and poor stability, particularly with noble metals (e.g., RuO2).
• Transition metal oxides often suffer from low atomic utilization and limited active site accessibility.

Purpose of the Study:

• To develop an efficient and stable electrocatalyst for the oxygen evolution reaction (OER).
• To address the limitations of current OER catalysts through novel material design and interface engineering.

Main Methods:

• Hydrothermal synthesis of Co-CoPBA nanocubes followed by WO3 nanorod loading.
• Gradient annealing under N2 atmosphere to form Co3O4@WO3 heterojunction.
• Electrochemical characterization and Density Functional Theory (DFT) calculations.

Main Results:

• The optimized 500 °C annealed catalyst formed a porous Co3O4@WO3 heterojunction with enhanced active sites (3.8 cm2 EASA) and charge transfer (55.12 mV dec-1 Tafel slope).
• Achieved an overpotential of 315 mV at 100 mA cm-2 in 1 M KOH, outperforming RuO2 (372 mV).
• Demonstrated exceptional stability over 100 hours and DFT-confirmed optimized OOH* adsorption via interfacial electronic restructuring.

Conclusions:

• The WO3@Co-CoPBA derived catalyst offers a high-performance, low-cost alternative for OER.
• Interface engineering is a viable strategy for designing advanced transition metal-based electrocatalysts.
• The developed heterostructure significantly boosts OER activity and stability.