Silver Nanoparticles Confined in SBA-15 Mesoporous Silica and the Application as a Sensor for Detecting Hydrogen Peroxide

Silver nanoparticles within the pore channels of selectively grafted mesoporous silica SBA-15 were synthesized. Silanols on the external surface of as-SBA-15 were first capped by –Si(CH3)3 groups. After removal of the template of capped SBA-15 by calcination, silanols on the internal surface of SBA-15 were modified by 3-aminopropyltrimethoxysilane (APTMS), and then formaldehyde was grafted by amino groups of APTMS, and further Ag(NH3)2NO3SBA-15). High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), nitrogen adsorption/desorption isotherms, and UV-vis spectra confirm that the silver nanoparticles have been confined inside the channels of SBA-15. In addition, the Ag-mSBA-15 modified electrode (Ag-mSBA-15/GC) exhibited an excellent electrocatalytic activity toward the reduction of hydrogen peroxide (H2O2). The proposed H2O2 sensor exhibits a linear range of 48.5 μM–0.97 M with a detection limit of 12 μM (S/N=3 ) and analytical time of 10 seconds per sample.