Au-decorated Sb₂Se₃ photocathodes for solar-driven CO₂ reduction

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Photoelectrochemical (PEC) CO₂ reduction is a key technology for sustainable fuel production.
• Developing efficient and stable photoelectrode materials is crucial for advancing PEC CO₂ conversion.
• Novel material architectures are needed to enhance catalytic activity and selectivity.

Purpose of the Study:

• To investigate the performance of FTO/Au/Sb₂Se₃/TiO₂/Au photoelectrodes for PEC CO₂ reduction.
• To explore the role of TiO₂ as an electron transfer and protective layer.
• To optimize Au nanoparticle co-catalyst loading for improved syngas generation.

Main Methods:

• Fabrication of Sb₂Se₃ nanorods via spin coating.
• Coating Sb₂Se₃ with TiO₂ using atomic layer deposition (ALD).
• Deposition of Au nanoparticles as co-catalysts via photo-assisted electrodeposition.

Main Results:

• Achieved a photocurrent density of ~7.5 mA cm^-2 at -0.57 V vs. RHE.
• Demonstrated syngas generation with Faradaic efficiencies of 25 ± 6% for CO and 63 ± 12% for H₂.
• Observed nanorod-like Sb₂Se₃ structures and conformal TiO₂ coating via SEM.

Conclusions:

• Sb₂Se₃-based photoelectrodes with FTO/Au/Sb₂Se₃/TiO₂/Au architecture show potential for solar CO₂ conversion.
• The integrated TiO₂ layer enhances electron transfer and protection.
• Further optimization of Au co-catalyst loading can improve PEC CO₂RR performance.