Redox-Active Antimony Sulfide Frameworks for Dynamic Radioiodine Capture.

Area of Science:

• Materials Science
• Environmental Chemistry
• Nuclear Engineering

Background:

• Efficient radioactive iodine capture is vital for nuclear safety and environmental protection, especially under challenging high-temperature off-gas conditions.
• Existing methods face limitations in dynamic and high-temperature environments, necessitating novel adsorbent materials.

Purpose of the Study:

• To evaluate the iodine removal performance of two antimony sulfide frameworks (2D and 3D) under dynamic, high-temperature conditions.
• To compare the performance of the 3D antimony sulfide framework against benchmark adsorbents for radioactive iodine capture.

Main Methods:

• Systematic evaluation of static and dynamic iodine uptake capacities of 2D and 3D Sb2S3 frameworks.
• Radioactive dynamic adsorption setup using 131I2 to confirm application potential.
• Mechanism analysis using powder X-ray diffraction, X-ray photoelectron spectroscopy, and time-dependent Raman spectroscopy.

Main Results:

• Both 2D and 3D Sb2S3 frameworks showed modest static iodine uptake.
• The 3D Sb2S3 framework achieved a superior dynamic capacity (1.25 g g-1 at 373 K), outperforming SCU-SnS (0.88 g g-1) and Ag-loaded silica gel (0.54 g g-1).
• Mechanism analysis revealed iodine uptake via charge-transfer interactions and redox-induced SbI3 formation.

Conclusions:

• The 3D antimony sulfide framework demonstrates significant potential for advanced radioactive iodine capture in nuclear waste management.
• The study introduces a new design paradigm for redox-active metal sulfide adsorbents utilizing soft acid/base interactions and framework reactivity.
• This research offers a viable approach for enhancing nuclear safety and environmental protection through improved iodine removal technologies.