Oriented Built-in Electric Field Introduced by Surface Gradient Diffusion Doping for Enhanced Photocatalytic H₂...

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Element doping is common for visible-light photocatalysts, enhancing light absorption but risking carrier recombination.
• Dopants in photocatalysts can act as recombination centers, limiting efficiency.

Purpose of the Study:

• To develop a gradient phosphorus-doped CdS (CdS-P) homojunction nanostructure.
• To create an oriented built-in electric field for efficient charge carrier extraction.
• To improve solar-to-chemical conversion efficiency in photocatalysis.

Main Methods:

• Fabrication of gradient phosphorus-doped CdS (CdS-P) homojunction nanostructures.
• Utilizing surface gradient diffusion doping.
• Characterization of photocatalytic activity for hydrogen evolution.

Main Results:

• Achieved an apparent quantum efficiency (AQY) of 8.2% at 420 nm without cocatalysts.
• Demonstrated a hydrogen evolution rate of 194.3 μmol·h⁻¹·mg⁻¹, 58.3 times higher than pristine CdS.
• Established an oriented built-in electric field for efficient carrier extraction.

Conclusions:

• Gradient doping creates a built-in electric field, effectively separating photogenerated electrons and holes.
• The CdS-P homojunction shows significantly enhanced photocatalytic performance for hydrogen production.
• This strategy offers a new pathway for designing efficient semiconductor photocatalysts for solar energy conversion.