Composite p-Si/Al₂O₃/Ni Photoelectrode for Hydrogen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Photocatalysis

Background:

• Efficient hydrogen evolution reaction (HER) is crucial for renewable energy.
• Silicon-based photoelectrodes require surface passivation and catalytic modification for improved performance.
• Protecting the silicon surface from corrosion while enhancing catalytic activity is a key challenge.

Purpose of the Study:

• To develop and characterize a novel photoelectrode for enhanced HER.
• To investigate the role of an ultrathin alumina layer in silicon photoelectrode performance.
• To evaluate the catalytic effect of nickel microformations on the hydrogen evolution rate.

Main Methods:

• Fabrication of p-type silicon photoelectrode passivated with atomic layer deposition (ALD) alumina.
• Photoelectrochemical deposition of nickel catalyst microformations.
• Characterization using grazing incidence X-ray diffraction (GI-XRD), optical profilometry, and spectroscopic ellipsometry (SE).
• HER rate measurements and stability tests in acid electrolyte.

Main Results:

• The 10 nm alumina layer improved electronic properties and protected the silicon surface.
• Nickel catalyst microformations increased the HER rate by one order of magnitude.
• The alumina film exhibited an amorphous structure and stability in acidic conditions.
• Annealing the alumina film increased its electrical resistance.

Conclusions:

• The developed alumina-passivated silicon photoelectrode with nickel catalyst shows significant potential for efficient HER.
• ALD alumina serves as an effective passivation and deposition-enabling layer.
• The combined approach offers a promising strategy for advanced photoelectrocatalytic systems.