Improving water oxidation performance by implementing heterointerfaces between ceria and metal-oxide nanoparticles

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrolytic hydrogen production via water splitting faces challenges in material stability and efficiency.
• Metal oxides offer stability but limited effectiveness in oxygen evolution reactions (OERs), often requiring precious metals.
• Developing robust and efficient electrocatalysts is crucial for sustainable hydrogen generation.

Purpose of the Study:

• To design and investigate metal oxide/metal oxide (MO/MO) nanoparticle heterointerfaces for enhanced OER performance.
• To improve the stability and reduce the overpotential required for water oxidation.
• To explore the potential of MO/MO heterointerfaces as alternatives to precious metal catalysts.

Main Methods:

• Synthesis and characterization of MO/MO nanoparticle heterointerfaces, specifically CeO2/Co3O4, CeO2/CuO, and CeO2/NiO.
• Electrochemical evaluation of OER performance, including onset potential and photoactivity measurements.
• Density functional theory (DFT) calculations to understand the interfacial effects on adsorption and reaction energetics.

Main Results:

• MO/MO heterointerfaces exhibited significantly improved onset potential and photoactivity compared to single metal oxides.
• CeO2/Co3O4 demonstrated a substantial cathodic shift in onset potential (~0.4 V vs. CeO2, ~0.3 V vs. Co3O4).
• DFT calculations revealed that adsorption preference and reaction free energy at the CeO2/Co3O4 interface are key factors in OER enhancement.

Conclusions:

• MO/MO nanoparticle heterointerfaces are promising for efficient and stable oxygen evolution reactions.
• The designed heterointerfaces offer a viable strategy to enhance electrocatalytic activity for water splitting.
• Understanding interfacial phenomena is critical for designing next-generation electrocatalysts for hydrogen production.