Interfacial electron transfer in heterojunction nanofibers for highly efficient oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts for the oxygen evolution reaction (OER) are crucial for electrochemical devices.
• Understanding electron transfer mechanisms in heterogeneous electrocatalysts remains a challenge.

Purpose of the Study:

• To develop and investigate a novel heterostructure electrocatalyst for enhanced OER activity.
• To elucidate the structure-activity relationship and electron transfer mechanisms.

Main Methods:

• Synthesis of Sr_0.9Ce_0.05Fe_0.95Ru_0.05O₃ fibers hybridized with in situ grown RuO₂ nanoparticles (SCFR-RuO₂).
• Experimental characterization and theoretical calculations to study structure and electron transfer.
• Evaluation of OER performance, including overpotential and Tafel slope.

Main Results:

• The SCFR-RuO₂ heterostructure exhibits an optimized OER overpotential of 295 mV at 10 mA cm^-2.
• Promoted electron transfer and OER kinetics were observed due to electronic coupling at the heterostructure interface.
• A triangular relationship between overpotential, Tafel slope, and work function was proposed as an OER activity descriptor.

Conclusions:

• The SCFR-RuO₂ heterostructure effectively enhances OER performance through synergistic electronic effects.
• The findings provide a framework for designing perovskite electrocatalysts by tuning work functions for improved OER activity.