Selective sorption of uranium from aqueous solution by graphene oxide-modified materials

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Uranium contamination in aqueous solutions poses significant environmental and health risks.
• Graphene oxide (GO) and its derivatives are explored for adsorptive removal of heavy metals.
• The role of surface functional groups in enhancing sorption selectivity is crucial.

Purpose of the Study:

• To investigate the sorption behavior of uranium onto carboxyl-functionalised graphene oxide (COOH-GO).
• To compare the uranium sorption efficiency of COOH-GO with pristine graphene oxide (GO) and graphite.
• To evaluate the impact of carboxyl functional groups on the selectivity of uranium sorption in the presence of competing ions.

Main Methods:

• Batch experiments were conducted to study the sorption of uranium ions.
• Carboxyl-functionalised graphene oxide (COOH-GO), graphene oxide (GO), and graphite were used as sorbent materials.
• Distribution coefficients were measured to quantify sorption performance and selectivity.

Main Results:

• COOH-GO exhibited superior performance in the selective removal of uranyl ions from aqueous solutions.
• The distribution coefficient for COOH-GO was 3.72 × 10³ mL g⁻¹, significantly higher than GO (3.97 × 10² mL g⁻¹) and graphite (2.68 × 10² mL g⁻¹).
• Increased abundance of carboxyl groups enhanced the selectivity of uranium sorption.

Conclusions:

• Carboxyl-functionalised graphene oxide is a highly effective and selective sorbent for uranium removal.
• The functionalization of graphene oxide with carboxyl groups significantly improves its capacity for uranyl ion adsorption.
• COOH-GO presents a promising material for environmental remediation applications targeting uranium contamination.