Engineering n-p junction for photo-electrochemical hydrogen production

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Solar-to-fuel technology aims to produce sustainable fuels using sunlight.
• Efficient, durable, and cost-effective photocathodes are crucial for solar hydrogen production.
• Photocorrosion degrades photocathode performance, limiting device longevity.

Purpose of the Study:

• To protect Cu/Cu2O/CuO photocathodes from photocorrosion.
• To enhance the stability and efficiency of hydrogen evolution reactions.
• To investigate the use of barium titanate perovskite as a protective layer.

Main Methods:

• A 200-300 nm thick BaTiO3 perovskite layer was deposited onto a Cu/Cu2O/CuO photoelectrode using the sol-gel method.
• The protected photoelectrode was tested for hydrogen production under 3 Sun irradiation in an aqueous electrolyte (pH=6).
• Performance was evaluated by measuring current density and monitoring activity decay over time.

Main Results:

• The BaTiO3-protected Cu/Cu2O/CuO photoelectrode achieved a current density of ~3.1 mA cm-2 at 0 V versus RHE.
• Protected photoelectrodes showed significantly improved stability, with only ~10% current decay over 20 minutes.
• Unprotected electrodes exhibited rapid activity decay, highlighting the effectiveness of the BaTiO3 protection.

Conclusions:

• Barium titanate perovskite layers effectively protect Cu/Cu2O/CuO photocathodes against photocorrosion.
• This protection strategy enhances the stability and performance of photoelectrodes for solar hydrogen generation.
• The findings contribute to the development of more durable and efficient solar fuel technologies.