C-Dot TiO₂ nanorod composite for enhanced quantum efficiency under direct sunlight.

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Developing sustainable and efficient photocatalysts is crucial for environmental remediation.
• Titanium nanotubes (TiNRs) show promise but often require enhancement for optimal performance.
• Carbon dots (C-dots) derived from biomass offer unique electronic and optical properties.

Purpose of the Study:

• To synthesize a novel composite photocatalyst using sustainable C-dots and TiNRs.
• To investigate the structural, optical, and electronic properties of the composite.
• To evaluate the solar photocatalytic performance for methyl orange degradation.

Main Methods:

• Hydrothermal synthesis of C-dots/TiNR composite.
• Characterization using FESEM, XRD, Raman, XPS, PL, FTIR, and UV-vis-DRS.
• Solar photocatalytic degradation of methyl orange (MO).

Main Results:

• The composite exhibited a band gap of 2.49 eV with a crystalline size of 24.80 nm.
• Photoluminescence analysis confirmed C-dots act as electron donors to TiNRs.
• Achieved 93.3% MO degradation within 150 min, following pseudo-first-order kinetics (k = 0.01723 min⁻¹).
• Reactive oxygen species (ROS) were identified as key mediators in MO degradation.

Conclusions:

• The C-dots/TiNR composite demonstrates superior solar photocatalytic activity compared to TiNR alone.
• The simple hydrothermal method is effective for large-scale, eco-friendly photocatalyst production.
• The composite shows significant potential for removing organic contaminants from water.