Bandgap-engineered nitrogen plasma functionalized biochar-TiO₂ composite for enhanced antibiotic photodegradation

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Titanium dioxide (TiO2) photocatalysts suffer from wide bandgaps and rapid charge recombination, limiting their efficiency.
• Ciprofloxacin, a common antibiotic, poses environmental risks due to incomplete removal by conventional methods.

Purpose of the Study:

• To engineer a nitrogen plasma-functionalized biochar-TiO2 composite for enhanced ciprofloxacin photodegradation.
• To overcome the limitations of pristine TiO2 through synergistic effects with biochar and nitrogen doping.

Main Methods:

• Biochar derived from textile sludge was synthesized via pyrolysis.
• Biochar-TiO2 composites were prepared using sol-gel and wet precipitation methods.
• Nitrogen doping was achieved through AC plasma treatment, confirmed by EDX and UV-vis DRS.

Main Results:

• The nitrogen-doped composite exhibited a narrowed bandgap (2.73 eV) and improved dispersion (90-106 nm hydrodynamic diameter).
• Photocatalytic degradation rates for ciprofloxacin were significantly enhanced, showing a 9-fold increase compared to pristine TiO2.
• The composite maintained high efficiency even at higher antibiotic concentrations, attributed to synergistic adsorption and ROS generation.

Conclusions:

• Plasma-doped biochar-TiO2 composites are highly effective photocatalysts for antibiotic remediation.
• The engineered material offers a promising solution for wastewater treatment and environmental pollutant removal.
• Synergistic effects between biochar adsorption and bandgap-engineered TiO2 enhance photocatalytic performance.