Effect of humidity on the CO gas sensing of ZnSn(OH)6 film via quartz crystal microbalance technique

In this study, cubic ZnSn(OH)6 (ZHS) was successfully synthesized via hydrothermal method at 120 °C for 12 h. The prepared material was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and SEM. The average size of the cubic ZHS was about 90-140 nm and thickness of ZHS film was 2 μm approximatively. CO with the volumetric fraction ranging from 4% to 10% in different relative humidity (10% RH, 44% RH, 73% RH and 95% RH) was used as active gas, high-purity N2 in same humility gas was used as cleaning process. The adsorption and desorption data were obtained by quartz crystal microbalance (QCM). The results of QCM show opposite adsorption and desorption process in the lower and higher humidity. The sensor coated with ZHS film exhibits promising CO gas and humidity sensing properties at the same time at room temperature.