CdSe Quantum Dots/g-C₃N₄ Heterostructure for Efficient H₂ Production under Visible Light Irradiation

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Graphitic carbon nitride (g-C₃N₄) is a promising material for photocatalysis but suffers from limited visible light absorption and charge carrier recombination.
• Quantum dots (QDs) offer tunable optical properties and high surface area, making them attractive for enhancing photocatalyst performance.

Purpose of the Study:

• To construct novel CdSe QDs/g-C₃N₄ heterostructure photocatalysts.
• To investigate the structure, composition, and optical properties of the synthesized materials.
• To evaluate the photocatalytic activity for visible-light-induced hydrogen (H₂) evolution.

Main Methods:

• Synthesis of CdSe quantum dots (QDs) and g-C₃N₄.
• Fabrication of CdSe QDs/g-C₃N₄ composite photocatalysts.
• Characterization using techniques to analyze structure, composition, and optical properties.
• Photocatalytic testing for H₂ evolution under visible light.

Main Results:

• Successfully constructed CdSe QDs/g-C₃N₄ photocatalysts.
• CdSe QDs/g-C₃N₄ exhibited significantly enhanced photocatalytic activity for H₂ evolution compared to pristine g-C₃N₄ and CdSe QDs.
• A composite with 13.6 wt % CdSe QDs showed the highest H₂ production rate.
• Enhanced performance attributed to synergistic effects, including improved visible light absorption and charge separation efficiency.

Conclusions:

• The CdSe QDs/g-C₃N₄ heterostructure is an effective photocatalyst for visible-light-driven H₂ evolution.
• The synergistic effects between CdSe QDs and g-C₃N₄ are crucial for the enhanced photocatalytic activity.
• This work provides a facile method for fabricating QD-modified g-C₃N₄ and designing advanced heterostructures.