Humidity sensing performance of mesoporous CoO(OH) synthesized via one-pot hydrothermal method

A humidity-responsive material of mesoporous CoO(OH) was synthesized successfully via one-pot hydrothermal method and the influence of CoO(OH) precursor concentration on humidity sensitive performance was studied. The structure and morphology of mesoprous CoO(OH) was characterized by X-ray Diffraction, Infrared spectra, Nitrogen adsorption and desorption, Scanning electron microscope, Transmission electron microscope and so on. The optimized mesoporous CoO(OH) based sensor showed the best linearity and high humidity sensitivity over a wide range of the humidity range (11–95% RH). Its impedance changed nearly four orders of magnitude and the response time was about 1.6 s. Humidity sensing mechanism was discussed in detail.