Ultrahigh humidity sensitivity of graphene oxide combined with Ag nanoparticles

Abstract

Novel capacitive-type humidity sensors with ultrahigh sensitivity based on graphene oxide (GO) combined with Ag nanoparticles (AgNPs) in different concentrations are reported in this study.

Graphene Oxide Papers in Nanogenerators for Self-Powered Humidity Sensing by Finger Tapping

“…At low RH, water molecules are primarily physisorbed and condensed onto the available active sites (including hydrophilic groups and vacancies) of the GO surface through double hydrogen bonding 42 . In such circumstances, the water molecules form an obstacle to electrostatically induced charges between the induced negative charges on the Kapton and the induced positive charges on the GO film via reducing the contact surface, resulting in the formation of a depletion region.…”

Fabrication and Characterization of Humidity Sensors Based on Graphene Oxide–PEDOT:PSS Composites on a Flexible Substrate

“…Thus, it can be recognized that, even after 2000 bending cycles, the change in the normalized resistance was below 15%, which indicated that the presented sensors also exhibit good stability and reversibility under bending cycles. the PEDOT:PSS chains, which took a longer time [11,55]. For that, the response was ~25% slower than that obtained with the sensor incorporated in the climate chamber for high values of RH.…”

“…At low RH, the response of the sensor was faster since the water molecules were physisorbed onto the available active sites (hydrophilic groups and vacancies) of the GO surface, without penetrating the GO layers. However, at high RH levels, the increase in both capacitance and sensitivity occurred due to the permeation of the water molecules within the GO layers, as well as due to their interaction with the PEDOT:PSS chains, which took a longer time [11,55]. For that, the response was~25% slower than that obtained with the sensor incorporated in the climate chamber for high values of RH.…”

The rapid response and high sensitivity of a ruthenium-doped copper ferrite thin film (Ru–CuFe2O4) sensor

“…1 In particular, the development and use of sensors that are highly sensitive to low relative humidity environments is very important for effectively monitoring ultra-clean chambers, chemical storage units, integrated chips, and manufacturing units. 2 And rapidresponse sensors can be used to precisely determine relative humidity values at the low relative humidity range. In this regard, a focus must be made on nding highly potent nanomaterials for the fabrication of rapid-response humidity sensors.…”