Enhanced NO2 gas sensing properties of ZnO-PANI composite nanofibers

Composite materials are excellent candidates for gas detection owing to the synergetic effects of different materials within the resulting composite. In this study, ZnO-polyaniline (PANI) composite nanofibers (NFs) were synthesized for NO2 sensing studies. Initially, the optimal mean diameter of the electrospun zinc acetate-PVA NFs was predicted theoretically using the response surface methodology (RSM). After the optimization studies, the electrospun ZnO NFs were synthesized, and different amounts of PANI (10, 25, and 50 wt %) were added to ZnO NFs to explore the effect of PANI on the NO2 gas sensing characteristics of the resulting composite. The thermal, structural, chemical, and morphological properties of the synthesized composites were examined. The NO2 gas sensing response was evaluated at different temperatures. The sensor with 25 wt % PANI showed the best performance to NO2 gas with good selectivity, exhibiting a high response of 40 to 10 ppm NO2 gas at 300 °C. Details of the sensing mechanism are presented. The ZnO-PANI composite NFs showed great potential for NO2 gas sensing.