Metal–organic frameworks (MOFs) toward SO2 detection

Developing technology that can precisely monitor specific air pollutants in diverse settings is essential to control emissions and ensure safe exposure limits are not exceeded. Metal–organic frameworks (MOFs) are crystalline organic–inorganic hybrid materials, which are promising candidates for SO₂ detection. Their chemically mutable periodic structure confers outstanding surface area, thermal stability, and a well-defined pore distribution. Moreover, MOFs have exhibited extraordinary performance for SO₂ capture. Therefore, research has focused on their possible applications for SO₂ sequestration due to the selective and robust chemical and physical interactions of SO₂ molecules within MOFs. The variable SO₂ affinity presented by MOFs enables the adsorption mechanism and preferential adsorption sites to be resolved. However, for MOF-based SO₂ detection, selective SO₂ capture at shallow partial pressure (0.01–0.1 bar) is required. Thus, capturing SO₂ at low concentration is crucial for SO₂ detection, where textural properties of MOFs, mainly the pore-limiting diameter, are essential to achieve selective detection. In this review, we discuss the fundamental aspects of SO₂ detection in MOFs, providing a step-by-step methodology for SO₂ detection in MOFs. We hope this review can provide valuable background around SO₂ detection in MOFs and inspire further research within this new and exciting field.