Biochar-loaded Ce³⁺-enriched ultra-fine ceria nanoparticles for phosphate adsorption

Area of Science:

• Environmental Science
• Materials Science
• Nanotechnology

Background:

• Phosphate contamination in water poses significant environmental risks.
• Development of efficient adsorbents for phosphate removal is crucial for water treatment.
• Cerium oxide nanoparticles offer potential for pollutant adsorption due to their unique properties.

Purpose of the Study:

• To synthesize biochar-loaded cerium oxide nanoparticles (Ce-BC) with high Ce³⁺ content.
• To evaluate the efficiency of Ce-BC as an adsorbent for phosphate removal from water.
• To elucidate the adsorption mechanism and kinetics of phosphate onto Ce-BC.

Main Methods:

• Facile impregnation-precipitation-pyrolysis process for Ce-BC synthesis.
• Characterization using FTIR, XRD, SEM, HRTEM, and XPS.
• Phosphate adsorption experiments to determine kinetics and capacity at various pH levels.

Main Results:

• Synthesized Ce-BC featured ultra-fine ceria nanoparticles (2-5 nm) with high Ce³⁺ concentration (59.6%).
• Ce-BC demonstrated rapid phosphate adsorption kinetics, reaching equilibrium within 10 minutes.
• Maximum adsorption capacity reached 77.7 mg P g^-1 at pH 3.0, with CePO₄ nanocrystal formation as the primary mechanism.

Conclusions:

• The facile synthesis strategy yields high Ce³⁺ content materials with excellent phosphate adsorption capabilities.
• Ce-BC shows high effectiveness and stability for phosphate removal, indicating significant potential for water purification applications.
• The study highlights the critical role of Ce³⁺ in cerium oxide for efficient phosphate adsorption.