Ultrasensitive and low temperature gas sensor based on electrospun organic-inorganic nanofibers

Organic-inorganic hybrid material is one of the most promising materials for high performance gas sensors due to its improved properties like high sensitivity, selectivity, fast response time, flexibility and low power consumption. This work presents ultrasensitive, selective and low operating temperature H₂S gas sensor. It is based on metal-oxide nanoparticles (NPs) embedded in organic semiconductor polymeric nanofibrous (NFs) membrane containing an ionic liquid (IL). In this context, high surface area Tungsten(VI) oxide- Polyvinyl alcohol (WO₃-PVA) nanofibrous composite sensor material with average diameter of 130 ± 20 nm were synthesized with controlled morphology and interconnectivity through an electrospinning technique. The obtained WO₃ NPs-containing PVA nanofibrous sensing material was evaluated for its ability as a potential sensor for H₂S gas at different operating temperatures and gas concentrations. Results demonstrated that the fabricated sensor is ultrasensitive and selective for H₂S gas and exhibit an excellent reproducibility, and long-term stability. Furthermore, the sensor showed adequate response in a humid environment. It was also shown that nanofibers' membrane porosity and thickness control the sensing performance. The optimum operating temperature of 40°C with a detection threshold as low as 100 ppb with a response time of 16.37 ± 1.42 s were achieved. This combined high sensitivity, fast response time and low operating temperature (low-power consumption) provides clear evidence of the sensor's potential to outperform existing devices, which could pave the way for a commercial exploitation.