APTES functionalization in SBA-15: the effect on SO₂ capture and detection applications

The development of adsorbents for air pollutant remediation and effective monitoring is of interest. Then, the effect of the APTES functionalization ratio on the impact of the adsorption and detection of SO₂ molecules was evaluated. The higher APTES functionalization material (SBA-15_6.1APTES) shows a high uptake of 1.15 mmol g^-1 at 0.001 bar and 298 K. Fluorescence, time-resolved photoluminescence, and quantum yield experiments revealed a turn-on effect specifically for SO₂ molecules, indicating high selectivity, suggesting host-to-guest energy transfer. Attractively, XPS measurement provided an understanding of the mechanism, suggesting hydrogen bonding and dipole-dipole interactions as the main interactions between SO₂ molecules and SBA-15_6.1APTES. DFT calculations were performed to confirm these interactions. Furthermore, this study highlights the application of SBA-15 materials with different amino modifications for SO₂ treatment and provides insight into the interaction mechanism using experimental techniques.