Investigation of humidity sensing properties of ZnS nanowires synthesized by vapor liquid solid (VLS) technique

Abstract

a b s t r a c tZinc sulfide (ZnS) nanostructures were synthesized by vapor-liquid-solid (VLS) method which is based on thermal evaporation. The morphology, chemical composition and crystal structure of ZnS nanostructures were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The results of these studies revealed that wurtzite ZnS nanowires with diameters in range of 50-400 nm are obtained. In order to investigate the humidity sensing capability, quartz crystal microbalance (QCM) and electrical resistance measurement techniques were carried out at different relative humidity (RH) conditions between 33% and 100% RH at room temperature. QCM results show that the oscillating frequency of ZnS nanowires loaded on QCM crystal decreases in range of 33-84% RH, but increases at 90% and 100% RH. The sensitivity of ZnS nanowires-based sensor (R air /R RH ) increases over 1000 times from 33% to 100% RH. These experimental results show that ZnS nanowires have a great potential for humidity sensing applications at room temperature.

Bifacial Structures of ZnS Humidity Sensor and Cd-Free CIGS Photovoltaic Cell as a Self-Powered Device

“…For ZnS-based humidity sensors, it has been shown that water vapor will be adsorbed on the n-type ZnS surface. ZnS can work as a humidity sensor because the water molecules interact with the surface of the ZnS to influence surface conductivity and surface potential due to physical and chemical adsorption [8]. Goswami et al reported that the polar water molecules orient to permit hydrogen (H) and oxygen (O) bonding to the terminating S 2− and Zn 2+ ions.…”

Photocatalytic Performance of ZnS and TiO2Supported on AC Under Visible Light Irradiation

“…27,28) For the sake of improving the photocatalytis efficiency of ZnS or TiO 2 , nanoscale ZnS coupled TiO 2 photocatalyst have attracted a great deal of attention for potential applications such as purification of water or organic dyes. 29,30) However, as other powder photocatalysts, ZnS/TiO 2 nanoparticles have some disadvantages, such as low photoca-talysis efficiency in the visible light region, low utilization rate in practical applications owing to the fact that the generated electron/hole (e − /h + ) pairs are easily recombined, meanwhile there are some dispersion problems because this nanoparticles are easy to cohere. Thus one way of improving these defects is choosing an appropriate catalyst support.…”

Optical and Structural Properties of Cu Doped ZnS Nanocrystals: Effect of Temperature and Concentration of Capping Agent

“…In recent years, accordingly, Mn-doped, Cu-doped and Mn and Cu-codoped ZnS powders have received much attention in research because many functions can be added by transporting and controlling numerous types of spin state [14][15][16][17].…”