Constructing g-C₃N₄/Bi₂MoO₆ heterojunctions for efficient visible-light-driven RhB degradation

Area of Science:

• Materials Science
• Photocatalysis
• Environmental Chemistry

Background:

• Single-component photocatalysts struggle with visible light utilization and charge separation.
• Graphitic carbon nitride (g-C3N4) and bismuth molybdate (Bi2MoO6) are promising photocatalytic materials.

Purpose of the Study:

• To fabricate and characterize g-C3N4/Bi2MoO6 heterojunction composites.
• To investigate the photocatalytic activity of these composites for Rhodamine B (RhB) degradation.
• To elucidate the mechanism behind the enhanced photocatalytic performance.

Main Methods:

• Stirring-assisted heating-evaporation method for composite synthesis.
• Structural and spectroscopic characterization (e.g., XRD, SEM, XPS).
• Photocatalytic degradation experiments under visible light irradiation.
• Photoelectrochemical measurements and radical-trapping experiments.

Main Results:

• The 30% g-C3N4/Bi2MoO6 composite demonstrated the highest RhB degradation rate (0.01922 min-1), significantly outperforming pristine materials.
• Intimate interfacial coupling and electronic interactions were observed between g-C3N4 and Bi2MoO6.
• The heterojunction structure effectively promoted charge carrier kinetics and suppressed electron-hole recombination.
• Holes (h+) were identified as the primary active species, followed by superoxide radicals (O2-).

Conclusions:

• The g-C3N4/Bi2MoO6 heterojunction significantly enhances photocatalytic activity through improved charge separation and migration.
• Visible light-driven RhB degradation is effectively achieved using these novel composite materials.
• The findings offer a promising strategy for developing efficient photocatalysts for environmental remediation.