4,4′-Diaminodiphenyl Sulfone Functionalized SBA-15: Toluene Sensing Properties and Improved Proton Conductivity

4,4′-Diaminodiphenyl sulfone functionalized SBA-15 (DDS/SBA-15) with various loading amounts of DDS has been prepared via a postsynthesis grafting method. The 2D hexagonal mesoporous structures of these hybrids have been confirmed by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and N2 adsorption–desorption isotherms. The covalent grafting of DDS onto the SBA-15 was further confirmed by Fourier transform infrared spectroscopy (FT-IR). DDS/SBA-15 based quartz crystal microbalance (QCM) sensor shows good selectivity and quick response toward toluene vapor, and the detection limit is down to 20 ppb. Impedance spectroscopy measurements showed that the proton conductivity properties of DDS/SBA-15 depended on the loading amount of DDS. These hybrids demonstrated improved proton conductivities compared with pristine SBA-15, and a highest value of 2.26 × 10–4 S cm–1 has been observed when the DDS loading amount is 0.37 mmol g–1. Therefore, DDS/SBA-15 could serve as a promising candi...