Efficient removal of U(VI) from aqueous solution using poly(amidoxime-hydroxamic acid) functionalized graphene oxide

Area of Science:

• Materials Science
• Environmental Chemistry
• Nuclear Chemistry

Background:

• Efficient uranium recovery is critical for resource utilization and environmental protection.
• Graphene oxide (GO) shows potential for contaminant removal, but its performance can be enhanced.
• Functionalization of GO can significantly improve adsorption capabilities for target pollutants.

Purpose of the Study:

• To synthesize and characterize a novel poly(amidoxime-hydroxamic acid) functionalized graphene oxide (pAHA-GO).
• To evaluate the adsorption efficiency and capacity of pAHA-GO for Uranium(VI) (U(VI)) removal.
• To assess the stability, reusability, and anti-interference properties of pAHA-GO for U(VI) capture.

Main Methods:

• Synthesis of pAHA-GO via free radical polymerization and oximation.
• Characterization using SEM, Raman spectroscopy, FT-IR, and XPS.
• Batch adsorption experiments to study U(VI) removal under various conditions (pH, time, concentration, ionic strength, interfering ions).

Main Results:

• pAHA-GO successfully incorporated amidoxime and hydroxamic acid groups.
• Adsorption followed pseudo-second-order kinetics and Langmuir isotherm models.
• Maximum U(VI) adsorption capacity reached 178.7 mg/g at pH 3.6.
• pAHA-GO demonstrated excellent reusability (up to 4 cycles), stability in acidic conditions, and anti-interference ability in simulated seawater (94% efficiency).

Conclusions:

• pAHA-GO is a highly efficient adsorbent for U(VI) capture from aqueous solutions.
• The functional groups on pAHA-GO play a key role in U(VI) adsorption.
• pAHA-GO shows significant promise for practical applications in uranium recovery from diverse water sources.