The humidity-sensitive property of MgO-SBA-15 composites in one-pot synthesis

MgO-SBA-15 has been successfully developed as a kind of humidity-sensitive material. The structure of MgO-SBA-15 materials was characterized by XRD, IR spectroscopy, N2 adsorption–desorption, TEM and XPS. The study proved that the MgO did not destroy the mesoporous structure of SBA-15 via the characteristic results of XRD and N2 adsorption–desorption. Researchers built the thick film humidity sensors on the Al2O3 ceramic substrate with two Ag–Pd interdigital electrodes with five fingers. The sensor shows excellent humidity sensitivity from 11% to 95%RH, and it has very good response and recovery property. The response time is about 10 s and the recovery time is about 20 s. We found that the mesoporous structure of the sensing materials contributed to the humidity sensitivity. We discussed a possible mechanism based on the humidity sensor produced by MgO-SBA-15.