The Effect of Surface Hydroxyls on the Humidity-Sensitive Properties of LiCl-Doped ZnSn(OH)6 Sphere-Based Sensors

Abstract

Pure zinc hydroxystannate (ZnSn(OH)6) and LiCl-doped ZnSn(OH)6 have been synthesized through a facile wet chemical method. The LiCl-doped samples keep their original spherical morphology as pure ZnSn(OH)6, with some LiCl particles stuck to its surface, providing more active sites for the adsorption and desorption of water molecules. The influence of LiCl doping on the humidity-sensing properties was explored by varying the dopant concentration. The 16 wt% LiCl/ZnSn(OH)6 showed a better humidity-sensing performance than that of the pure ZnSn(OH)6 and other doped samples, including a high resistive sensitivity, a relatively small hysteresis, and a fast response speed. Through the FTIR analysis, the number of hydroxyl groups on the surface structure after aging has been found to decline markedly. These hydroxyl groups provide a platform for the adsorption of water molecules on the surface and promote the dissociation of water molecules. The detriment of aging to sensor performance should not be underrated. The complex impedance spectrum explains the mechanism of the sensor. These results demonstrate that ZnSn(OH)6 has potential application in fabricating humidity sensors, and the sensing performance of the sensor is enhanced by the dopant LiCl.

Performance analysis of hybrid solid liquid desiccant material: Dehumidification and CO2 absorption

“…By maintaining the favorable operating condition, proposed HSLD can be used effectively in continuous operation. In addition, the solid content present in HSLD, that is, CuO, SiO 2 , CaCl 2 , LiCl is also effective for CO removal 51,52 . So, these types of materials could be recommended for the different dehumidification as well as air purifying purposes in the controlled area.…”

“…In addition, the solid content present in HSLD, that is, CuO, SiO 2 , CaCl 2 , LiCl is also effective for CO removal. 51,52 So, these types of materials could be recommended for the different dehumidification as well as air purifying purposes in the controlled area. absorption in the bulk phase of desiccant liquid.…”

Designing High Performance Carbon/ZnSn(OH)6-Based Humidity Sensors

“…As shown in Figure 10c,d, the adsorbed water molecules gradually increase with the increase in humidity (43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54). The proton (H + ) combines with the water molecules adsorbed on it through the hydroxyl group to form H 3 O + [9], prone to leakage conductive flow, thus giving the CIS curve as a semicircular shape. The primary carrier in this stage is H 3 O + .…”

“…In low relative humidity environments, the sensing layer of The equivalent circuit diagram of CIS for C10-ZnSn(OH) 6 is presented in Figure 10i,j. At 11-54% RH, the semi-circular curve of CIS represents a sensing mechanism by dielectric correlation theory [9]. An equivalent circuit is fitted as a resistor (R f ) connected in parallel with a constant phase element (CPE f ), as shown in Figure 10i.…”

Heterojunctions of ZnO-Nanorod-Decorated WO3 Nanosheets Coated with ZIF-71 for Humidity-Independent NO2 Sensing

“…The gas mixture’s humidity environment was prepared using saturated inorganic salt solutions. The detailed preparation method was as follows: the relative humidity (RH) of 23, 33, 43, 52, 67, 75, and 85% were prepared by CH 3 COOK, MgCl 2 , K 2 CO 3 , Mg­(NO 3 ) 2 , CuCl 2 , NaCl, and KCl saturated solutions, respectively. , …”