Core-Shell Fe/FeS Nanoparticles with Controlled Shell Thickness for Enhanced Trichloroethylene Removal

Area of Science:

• Environmental Science
• Materials Science
• Nanotechnology

Background:

• Zero-valent iron nanoparticles (nZVI) are used for environmental remediation.
• Sulfidated nZVI (S-nZVI) shows promise but faces challenges in scalable, cost-effective production and shell property control.
• Existing synthesis methods are lab-scale and limit large-scale application.

Purpose of the Study:

• To develop a novel, scalable, and cost-effective method for synthesizing S-nZVI.
• To investigate the properties and performance of S-nZVI for trichloroethylene (TCE) remediation.
• To optimize S-nZVI synthesis for enhanced contaminant removal.

Main Methods:

• Synthesized S-nZVI by treating commercially available nZVI with sodium sulfide in a concentrated slurry.
• Characterized the core-shell structure and FeS shell thickness.
• Evaluated TCE removal efficiency and electron efficiency of the synthesized S-nZVI.

Main Results:

• Developed a scalable, off-site synthesis method for S-nZVI without hazardous boron residues.
• Achieved up to a 12-fold increase in TCE removal and a 7-fold increase in electron efficiency.
• Identified an optimal FeS shell thickness of approximately 7.3 nm for maximizing TCE degradation rates.

Conclusions:

• The novel S-nZVI synthesis method is scalable and cost-effective.
• S-nZVI significantly enhances TCE degradation, with complete dechlorination observed.
• The optimized S-nZVI particles are a promising agent for remediating TCE-contaminated sites.