Humidity sensing properties of Ag-loaded mesoporous silica SBA-15 nanocomposites prepared via hydrothermal process

Ag nanoparticle loaded mesoporous silica SBA-15 nanocomposites have been synthesized by a facile hydrothermal route with (C2H5O)(4)Si in the presence of (AgNO3). Their response towards humidity has been studied. Low angle X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), N-2 adsorption-desorption, High Resolution Transmission Electron Microscopy (HRTEM), Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy techniques were utilized to characterize the composition and structure of the samples. In comparison with pure SBA-15, the Ag-loaded SBA-15 exhibits improved humidity response within the relative humidity (RH) range of 11-92%. The optimal result were obtained for 5 wt% Ag-loaded SBA-15 sample, which demonstrate an excellent linearity, small hysteresis and high humidity sensitivity; moreover, it also exhibits satisfactory response and recovery time. The resistance shows change of more than 5 orders in magnitude over the entire humidity range. The mechanism for humidity sensing was studied. The investigation of humidity sensing characteristics of Ag-doped SBA-15 sensors indicates that the material has promising application as humidity sensor. (C) 2014 Elsevier Inc. All rights reserved.