Dendritic bio-inspired multidentate coordination aerogels for efficient uranium adsorption

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Selective uranium extraction from seawater is crucial but hindered by competing ions, biofouling, and cost.
• Existing adsorbents often lack the required capacity, selectivity, or stability for practical application.

Purpose of the Study:

• To develop a cost-effective and highly efficient adsorbent for selective uranium extraction from seawater.
• To investigate a bio-mimetic, multi-site synergistic adsorption strategy inspired by plant structures.

Main Methods:

• Fabrication of a phosphorylated multidentate coordination aerogel (CSPP) using sodium alginate (SA) and carboxymethyl chitosan (CMC) scaffolds with dendritic molecules.
• Evaluation of CSPP's adsorption capacity, selectivity, stability, and resistance to biofouling in natural seawater.
• Utilizing experimental and computational simulations to elucidate the adsorption mechanism.

Main Results:

• CSPP achieved a high uranium adsorption capacity (723.4 mg g⁻¹), significantly outperforming standalone materials.
• Demonstrated excellent selectivity (Kd = 4.0 × 10⁴) in natural seawater, along with superior stability and biofouling resistance.
• Identified a tetradentate chelation mechanism involving phosphate and carboxyl groups, enhanced by a crown ether.

Conclusions:

• The developed CSPP adsorbent offers an economically viable and efficient solution for uranium recovery from seawater.
• The bio-mimetic, multi-site synergistic adsorption strategy presents a promising blueprint for designing advanced adsorbents for valuable ion extraction.
• This work redefines the economic feasibility of seawater uranium extraction and highlights the potential of biomimetic design.