BODIPY Chemisorbed on SnO₂ and TiO₂ Surfaces for Photoelectrochemical Applications

Area of Science:

• Materials Science
• Photochemistry
• Renewable Energy

Background:

• Dye-sensitized photoelectrochemical cells (DSPECs) are crucial for solar fuel production via water splitting.
• Efficient solar fuel generation requires photosensitizers with strong covalent attachment to semiconducting electrodes.
• Optimizing charge transfer and minimizing recombination are key to high DSPEC efficiency.

Purpose of the Study:

• To compare a novel boron-anchoring mode of BODIPY dyes against traditional carboxylic acid anchoring.
• To evaluate the impact of anchoring strategy on electron injection, binding stability, and photocurrent generation.

Main Methods:

• Utilized terahertz and transient absorption spectroscopy to probe electron dynamics.
• Performed interfacial electron transfer simulations.
• Conducted photoelectrochemical studies with sacrificial electron donors.

Main Results:

• Boron-bound BODIPY demonstrated faster electron injection into TiO2 and SnO2 compared to carboxylic acid-bound dyes.
• The boron anchor provided improved binding stability across a wide pH range, despite lower surface coverage.
• Photoelectrochemical tests showed sustained photocurrent and good stability during long-term irradiation.

Conclusions:

• The novel boron-anchoring mode offers superior electron injection and enhanced stability for BODIPY dyes in DSPECs.
• This binding strategy shows significant promise for advancing solar fuel production technologies.
• Further research into boron-bound BODIPY dyes is warranted for future DSPEC applications.