HFIP-functionalized electrospun WO3 hollow nanofibers/rGO as an efficient double layer sensing material for dimethyl methylphosphonate gas under UV-Light irradiation

Abstract Gas sensing materials-based transition metal oxides have insufficient sensing properties that limit their application. Inorganic-organic hybrid nanomaterials are the most advanced materials for high sensitivity gas sensors. Herein, hexafluoroisopropanol (HFIP) was grafted on the tungsten trioxide (WO3) hollow nanofibers (HNFs) for detecting dimethyl methylphosphonate (DMMP, sarin agent simulant) due to the hydrogen bonding. Furthermore, reduced Graphene Oxide (rGO) nanosheets were applied as a base layer to avoid the grain boundaries poisoning and enhance the charge mobility. As well, the UV-light photoactivation of the sensing materials was investigated. The double layer rGO/WO3–HFIP exhibited high and rapid responses toward DMMP in comparison with WO3 HNFs and double layer rGO/WO3 after the exposure to various gases. The sensing performance of all sensors improved under UV-light irradiation, demonstrating the UV-light activation of their sensing properties. The double layer rGO/WO3–HFIP showed a high response (17.6) at 150 °C of 10 ppm DMMP with maintaining 90% of it at a relative humidity (80 RH %). In addition to a low detection limit of 0.1 ppm DMMP, indicating the role of HFIP as a hinter of DMMP molecules. This work provides an efficient synthetic method of double layer rGO/WO3–HFIP sensing material for DMMP detection.