Robust copper-based cationic metal-organic frameworks for efficient sequestration of perrhenate/pertechnetate

Area of Science:

• Materials Science
• Environmental Chemistry
• Nuclear Engineering

Background:

• Cationic metal-organic frameworks (MOFs) are explored for perrhenate/pertechnetate (ReO4-/99TcO4-) capture from wastewater.
• Existing MOFs lack stability in acidic and alkaline environments, limiting nuclear waste post-processing applications.

Purpose of the Study:

• To construct robust copper-based cationic MOFs (ZJU-X16 and ZJU-X17) with enhanced acid and alkali resistance.
• To evaluate their efficiency and mechanism for sequestering perrhenate/pertechnetate from aqueous solutions.

Main Methods:

• Synthesis of ZJU-X16 and ZJU-X17 MOFs.
• Sorption experiments under varying pH conditions (pH 1, 13, and neutral).
• Material characterization using SEM-EDS, XPS, FT-IR, and DFT calculations.

Main Results:

• ZJU-X16 demonstrated high ReO4- removal efficiency (68.6% at pH 1, 68.5% at pH 13).
• ZJU-X17 maintained structural integrity in 15 M NaOH.
• Anion-exchange mechanism confirmed, with ZJU-X16 showing superior ReO4- sorption selectivity.

Conclusions:

• Developed acid- and alkali-resistant MOFs (ZJU-X16, ZJU-X17) for effective perrhenate/pertechnetate sequestration.
• These MOFs present a viable solution for nuclear wastewater treatment, addressing stability limitations of previous materials.