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

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.