UTSA-16(Zn) for SO₂ detection: elucidating the fluorescence mechanism

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for various applications.
• Developing sensitive and selective gas detectors is crucial for environmental monitoring.
• Fluorescence-based detection provides a sensitive method for analyzing analytes.

Purpose of the Study:

• To investigate the potential of UTSA-16(Zn) MOF as a fluorescence-based detector for sulfur dioxide (SO2).
• To characterize the synthesized UTSA-16(Zn) material and evaluate its sensing performance.
• To elucidate the mechanism behind the fluorescence quenching upon SO2 interaction.

Main Methods:

• Synthesis and characterization of UTSA-16(Zn) using PXRD, FTIR, and TGA.
• Fluorescence spectroscopy analysis before and after SO2 exposure.
• Time-resolved photoluminescence (TRPL), XPS, and UV-vis spectroscopy to understand the quenching mechanism.

Main Results:

• UTSA-16(Zn) exhibited a significant decrease in fluorescence intensity upon exposure to SO2.
• A limit of detection (LOD) of 1.79 mM (approximately 114.6 ppm) for SO2 was achieved.
• Characterization confirmed the formation of a non-fluorescent complex in the ground state (GSC) via static quenching.

Conclusions:

• UTSA-16(Zn) demonstrates promising potential as a fluorescence sensor for SO2 detection.
• The sensing mechanism involves static quenching due to GSC formation.
• This MOF offers a viable platform for developing novel SO2 gas sensors.