Humidity Sensing Property of NaCl-Added Mesoporous Silica Synthesized by a Facile Way with Low Energy Cost

NaCl-added mesoporous silica SBA-15 was prepared by a simple grind method which needs low energy cost. Humidity sensing property was studied. Study results indicated that NaCl-added material possesses higher humidity sensitivity. Its impedance changed more than four orders of magnitude when the relative humidity changed from 11% RH to 95% RH. From the viewpoint of economy, NaCl-added SBA-15 material which possesses high sensitivity and needs low energy cost is more suitable to be a promising humidity sensing material. Complex impedance spectra, the corresponding equivalent circuit, and bode diagrams were carefully analyzed to explore sensing mechanism.