Photoelectrochemical Conversion from Graphitic C3N4 Quantum Dot Decorated Semiconductor Nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Graphitic carbon nitride (g-C3N4) is a promising metal-free photocatalyst.
• Synthesizing nanostructured g-C3N4 for photoelectrochemical (PEC) applications is challenging.
• Existing methods for nanostructured g-C3N4 are complex and time-consuming.

Purpose of the Study:

• To develop a facile method for synthesizing graphitic carbon nitride quantum dots (g-CNQDs).
• To create g-CNQDs directly grown on TiO2 nanowire arrays.
• To investigate the enhanced PEC performance of the g-CNQD/TiO2 heterojunction.

Main Methods:

• A one-step quasi-chemical vapor deposition (CVD) process was developed.
• g-CNQDs were synthesized directly onto TiO2 nanowire arrays.
• Density functional theory (DFT) calculations were used to analyze the synergistic effects.

Main Results:

• Uniform g-CNQDs were successfully grown on TiO2 nanowires, exhibiting photoluminescence.
• The g-CNQD/TiO2 heterojunction showed a significantly enhanced PEC photocurrent density (3.40 mA/cm²).
• The composite exhibited excellent stability, retaining ~82% photocurrent after 10 hours.

Conclusions:

• The developed method offers a facile route to g-CNQD-based composites for energy applications.
• The quantum and sensitization effects of g-CNQDs boost PEC performance.
• This approach facilitates the synthesis of various g-CNQD composites with other semiconductor nanowires.