Electrolyte Engineering Stabilizes Photoanodes Decorated with Molecular Catalysts.

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Molecular catalysts enhance photoanodes for solar water splitting.
• Stability of photoabsorbers and cocatalysts remains a key challenge.
• Electrode-electrolyte interface and tunable parameters like pH are often overlooked.

Purpose of the Study:

• To systematically investigate the activity-stability relationship of Fe2O3 photoanodes with Ir molecular catalysts.
• To understand the impact of electrolyte pH on catalyst performance and stability.
• To highlight the importance of electrolyte engineering for solar water splitting.

Main Methods:

• In situ mass spectroscopy was used to study catalyst dissolution.
• A comprehensive pH study was conducted on Fe2O3 photoanodes modified with Ir catalysts.
• Activity and stability were evaluated across different electrolyte pH values.

Main Results:

• Detailed insights into the dissolution behavior of the Ir cocatalyst were obtained.
• An inverse trend was observed between Fe and Ir stability at different pH levels.
• Optimal activity-stability synergy was achieved at pH 9.7.

Conclusions:

• Electrolyte engineering, specifically pH adjustment, is crucial for improving solar water splitting efficiency and catalyst stability.
• The study emphasizes the significance of the electrode-electrolyte interface.
• Findings advocate for considering photostability and electrolyte effects in catalyst design for solar water splitting.