Impedimetric humidity sensing studies of Ag doped MCM-41 mesoporous silica coated on silver sputtered interdigitated electrodes

Silver nitrate of desired concentration was doped in the as-synthesized MCM-41 mesoporous silica and the prepared samples are spin coated onto interdigitated thin films with silver on glass slide. The interdigitated thin film electrodes made of silver were fabricated by RF-magnetron sputtering with power of 60 W at 7.2 × 10^-2 mbar. The synthesized samples were characterized for structural and morphological features using Fourier-Transform Infrared Spectroscopy (FTIR), BET studies and Transmission Electron Microscopy (TEM). Effect of change in the impedimetric analysis for humidity across the interface has been explored. The impedance of Ag-MCM-41 sample changed five orders of magnitude across the humidity range 11%-93% RH. The xAg-MCM-41, where x = 0.07 g has been the better sample for humidity sensing at room temperature. The impedance studies indicate that the sensor system Ag-doped MCM-41 spin coated on silver sputtered interdigitated electrodes is an appropriate candidate to fabricate humidity sensors with enhanced sensing performance.