A carbon dot-based clay nanocomposite for efficient heavy metal removal

Area of Science:

• Materials Science
• Environmental Science
• Nanotechnology

Background:

• Carbon dots (CDs) exhibit remarkable photoluminescence properties, attracting significant research interest.
• Bentonite clay, an aluminosilicate material, is widely studied for adsorption applications.

Purpose of the Study:

• To prepare novel fluorescent bentonite clay modified with carbon dots (CDs) for lead removal.
• To investigate the characteristics and performance of the developed hybrid material as a lead adsorbent.

Main Methods:

• Hydrothermal synthesis of carbon dots from graphitic waste.
• Modification of bentonite clay with synthesized carbon dots to create nanocomposites.
• Characterization using XRD, FTIR, XPS, and fluorescence analysis.
• Adsorption experiments for lead (Pb(II)) removal under varying conditions (light/dark, time, pH).

Main Results:

• Successfully synthesized spherical, positively charged CDs (<5 nm) with fluorescence.
• Developed stable fluorescent bentonite-CD nanocomposites with excellent optical properties.
• Achieved 95% lead removal efficiency in 10 minutes under light conditions, significantly higher than in dark conditions (70%).
• Adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models.
• Maximum adsorption capacity reached 400 mg/g for Pb(II) at room temperature and pH 8 under light.

Conclusions:

• UV light-responsive carbon dot-intercalated clay is an efficient hybrid platform for lead removal.
• The material demonstrates high Pb(II) adsorption capacity and long-term stability.
• The developed nanocomposite offers a promising solution for environmental remediation of lead contamination.