Design Rule for Highly Stable Efficient High-Entropy Metal Oxide Electrocatalysts: Complementary Roles of 3d...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• High-entropy materials offer tunable properties for advanced applications.
• Developing stable and efficient metal oxide electrocatalysts requires understanding fundamental component selection principles.
• Manganese dioxide (MnO2) is a promising base material for electrocatalysts.

Purpose of the Study:

• To investigate the role of 3d transition metals in enhancing the performance and stability of MnO2-based electrocatalysts.
• To establish design principles for efficient high-entropy metal oxide electrocatalysts.
• To explore the impact of multi-metal substitution on the electronic and structural properties of MnO2 nanowires.

Main Methods:

• Systematic investigation of 3d transition metal (V, Fe, Co, Ni) substitution in MnO2 nanowires.
• Characterization of electronic configuration and crystal morphology changes.
• Electrocatalytic performance testing for the oxygen evolution reaction (OER).
• In situ Raman spectroscopy and density functional theory (DFT) calculations.

Main Results:

• Quinary-metal-based α-MnVFeCoNiO2 nanowires demonstrated superior OER activity and stability compared to unsubstituted and lower-order substituted analogs.
• Single-metal substitution with V, Fe, Co, and Ni effectively improved electrocatalytic activity.
• Multi-metal substitution was shown to promote reaction intermediate adhesion during OER.
• Improvements attributed to suppressed lattice oxygen occupation, diverse active sites, enhanced transport, and accelerated kinetics.

Conclusions:

• Multi-metal substitution is a viable strategy for optimizing high-entropy MnO2 electrocatalysts.
• Design factors related to metal composition and electronic structure are critical for enhancing OER performance.
• The findings provide fundamental insights for designing next-generation high-entropy electrocatalysts.