Azo-Functional Indium-Based Metal-Organic Framework as a High-Performance Organic Iodides Adsorbent.

Area of Science:

• Materials Science
• Nuclear Chemistry
• Environmental Engineering

Background:

• Nuclear fuel reprocessing generates waste gases containing hazardous organic iodides.
• Existing materials lack sufficient affinity sites for efficient organic iodide capture.
• Developing advanced adsorbents is crucial for nuclear waste management.

Purpose of the Study:

• To design and synthesize a functionalized metal-organic framework (MOF) for enhanced organic iodide adsorption.
• To investigate the impact of functionalization on the adsorption properties of an indium-based MOF.
• To elucidate the adsorption mechanisms of organic iodides in MOFs.

Main Methods:

• Synthesis of a functionalized MOF (Post-SHF-61) via diazo coupling reaction on an indium-based MOF (SHF-61).
• Characterization of the synthesized material to confirm the introduction of azo bonds and enhanced electronic properties.
• Static adsorption experiments to quantify the adsorption capacities for methyl iodide (CH3I) and ethyl iodide (C2H5I) at 75 °C.

Main Results:

• The functionalized Post-SHF-61 exhibited significantly higher adsorption capacities for CH3I (1545 mg/g) and C2H5I (848 mg/g) compared to the precursor SHF-61 (591 mg/g and 271 mg/g, respectively).
• The diazo coupling reaction enhanced the conjugation and electron density of the organic component in the MOF.
• Detailed analysis of adsorption mechanisms and iodide species within the MOFs was performed.

Conclusions:

• The functionalized Post-SHF-61 demonstrates superior performance for organic iodide capture, addressing a key challenge in nuclear waste gas treatment.
• The strategy of enhancing MOF organic components through functionalization is effective for improving adsorption capacity.
• This research provides valuable insights for developing advanced MOF-based materials for environmental remediation and nuclear safety.