Sb₂Se₃/CdSe thin film photocathode for efficient hydrogen production

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Efficient solar-to-hydrogen conversion requires highly active narrow-band-gap photoelectrodes.
• Antimony selenide (Sb₂Se₃) based materials are promising for photoelectrochemical applications.

Purpose of the Study:

• To develop and characterize a novel Sb₂Se₃/CdSe/Pt photocathode for enhanced solar-to-hydrogen conversion.
• To investigate the photoelectrochemical (PEC) performance and understand the underlying mechanisms of the fabricated photocathode.

Main Methods:

• Fabrication of the Sb₂Se₃/CdSe/Pt photocathode via electrodeposition, annealing, and surface modification.
• Characterization of the photocathode's activity using photocurrent density measurements at various potentials.
• Investigation of the Sb₂Se₃ layer thickness effect on photocurrent generation.

Main Results:

• The Sb₂Se₃/CdSe/Pt photocathode achieved a photocurrent density of approximately -6.9 mA cm^-2 at -0.2 V_RHE.
• This performance represents a 2.3-fold increase compared to the Sb₂Se₃/Pt photoelectrode.
• The enhanced performance is attributed to the Sb₂Se₃/CdSe p-n heterojunction facilitating charge separation and transfer.

Conclusions:

• A novel Sb₂Se₃-based p-n heterojunction photocathode was successfully developed using a facile fabrication approach.
• The Sb₂Se₃/CdSe/Pt photocathode demonstrates significant potential for cost-effective solar-to-hydrogen conversion.
• Optimizing Sb₂Se₃ layer thickness is crucial for maximizing light absorption and hole transport in PEC devices.