Development of Phosphate-Functionalized Magnetic Core-Shell Nanoadsorbent for Rare Earth Element Recovery from LCD...

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Electronic waste poses a significant environmental challenge due to the valuable and critical elements it contains.
• Efficient recovery of rare earth elements (REEs) from waste streams is crucial for sustainable resource management and the circular economy.
• Developing selective and robust adsorbents is key to overcoming the complexities of extracting REEs from diverse waste matrices.

Purpose of the Study:

• To develop and characterize a core-shell magnetic nanoadsorbent (Fe3O4@TiO2) for the selective adsorption of REEs.
• To investigate the adsorption kinetics, capacity, and reusability of the nanoadsorbent for REE recovery.
• To validate the nanoadsorbent's performance in recovering REEs from real electronic waste leachates.

Main Methods:

• Synthesis of Fe3O4@TiO2 core-shell nanostructures via co-precipitation.
• Surface functionalization with organophosphorus groups for enhanced adsorption.
• Characterization using FT-IR spectroscopy and zeta potential analysis.
• Adsorption experiments to determine kinetics, capacity, and reusability, including desorption studies.
• Validation using real LCD screen leachates with pre-treatment steps.

Main Results:

• The functionalized Fe3O4@TiO2 nanoadsorbent exhibited pseudo-second-order adsorption kinetics for lanthanum, reaching equilibrium in 15 minutes.
• A theoretical model-calculated adsorption capacity of 19.4 ± 0.8 mg/g was achieved at pH 5.
• The material demonstrated good stability and reusability, retaining 75% capacity after five cycles with 58-60% desorption efficiency.
• Selective recovery of Gd, Y, Ce, Pr, Nd, and Sm from LCD leachates was achieved despite competing ions like Cu and Cr.

Conclusions:

• The developed Fe3O4@TiO2 nanoadsorbent is a promising material for the selective recovery of REEs from electronic waste.
• The surface functionalization significantly enhances adsorption performance and selectivity.
• This technology holds potential for advancing urban mining initiatives and contributing to a circular economy for critical materials.