Carbon-layer-protected cuprous oxide nanowire arrays for efficient water reduction

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Semiconductor nanostructures are crucial for energy conversion but suffer from photocorrosion.
• Developing protective layers is essential to enhance their stability and performance.

Purpose of the Study:

• To develop a solution-based strategy for creating protective carbon coatings on unstable semiconductor nanostructures.
• To address the photocorrosion issue and improve the efficiency of photoelectrochemical devices.

Main Methods:

• A solution-based coating of glucose as a carbon precursor was applied to cuprous oxide (Cu₂O) nanowire arrays.
• Subsequent carbonization formed a thin protective carbon layer.
• Electrochemical performance and photostability were evaluated under AM 1.5G illumination.

Main Results:

• Carbon-layer-protected Cu₂O nanowire arrays showed significantly improved photostability (80.7% vs. 12.6%).
• Enhanced photocurrent density reached -3.95 mA cm⁻² with an optimal photocathode efficiency of 0.56%.
• This represents the highest reported value for a Cu₂O electrode with a metal/co-catalyst-free protective layer.

Conclusions:

• The facile carbon coating strategy effectively prevents photocorrosion in semiconductor nanostructures.
• This approach offers a general solution for enhancing the stability of various photoelectrodes.
• The method holds significant potential for advancing energy conversion technologies.