Facile fabrication of flexible SiO2/PANI nanofibers for ammonia gas sensing at room temperature

Abstract

Herein, we report a novel ammonia (NH3) sensor material with outstanding sensing performance based on free-standing polyaniline (PANI) coated inorganic silica (SiO2) nanofibers (SNF) membranes, which could work well at room temperature. SNF membranes were prepared by the combination of sol-gel, electrospinning and calcination methods It was realized per the results that the flexibility of SNF membranes could be considerably controlled by calcination temperature. SNF were diverted from flexible to brittle as the temperature increased from 600°C to 1000°C. In order to adapt to wearable gas senor demands, flexible SNF membranes obtained from heat-treated at 600°C and 800°C were used as templates for in-situ polymerization of aniline. The gas sensing behavior of PANI coated SNF of 10ppm to 300ppm NH3 were operated at room temperature. Gas sensing tests revealed that the SNF/PANI composite nanofibers had high response values. Additionally, the gas sensing abilities of PANI coated on SNF annealed at 800°C was much higher than SNF treated at 600°C. Moreover, the PANI coated SNF (annealed at 800°C) could detect NH3 to 400 ppb, as well as showed excellent selectivity, repeatability and reversibility. The flexible SNF/PANI membranes were easy to prepare and it obtained ideal flexibility, which exhibited their potential for applying as wearable gas senor.