Flexible fabric gas sensors based on PANI/WO3 p−n heterojunction for high performance NH3 detection at room temperature

Abstract

A PANI/WO3@cotton thread-based flexible sensor that is capable of detecting NH3 at room temperature is developed here. A layer of WO3 with PANI nanoparticles can be deposited by in-situ polymerization. The morphology and structure of the specimens were investigated by utilizing TEM, SEM, XRD and FTIR. The sensing performance of the PANI/WO3@cotton sensors with different WO3 molar ratios to NH3 at room temperature was examined. The results show that the optimal sensor (10 mol% WO3) has a response of 6.0 to 100 ppm NH3, which is significantly higher than that of the sensors based on pristine PANI and other composites. The PANI/WO3@cotton sensor also displays excellent selectivity, gas response, and flexibility even at room temperature. The unique fiber structure, p-n heterojunction, and the increased protonation of PANI in the composites contribute to the enhanced sensing property.