Low operating temperature N-ZnO/PANI chemiresistive acetone gas sensor

In the advances of electronic miniaturization, a power efficient wireless gas sensor is desirable. In order to reduce gas sensor working temperature and improve lower limit of detection (LOD) as well as increase response toward acetone gas in this study, ZnO was first synthesized into porous nanosheet network before it was in-situ ball-milled and nitrogen (N) doped, followed by mixing with polyaniline (PANI). Ultimately, the N-ZnO was combined with PANI into composites of 5 wt%, 10 wt%, and 20 wt% of PANI to N-ZnO in order to scrutinize the effects of combining different weight percent of nitrogen-doped ZnO (N-ZnO) to PANI. Investigation on morphology of sample using X-ray diffractometer found that in-situ ball milling and nitrogen doping had induced lattice strain to the ZnO morphology. The rise in carrier concentration in N-ZnO could be the advantageous feature that enhanced the sensor LOD which also promptly decreased the working temperature. On the other hand, the increased in acetone response of the sensor is due to the heterojunction of N-ZnO/PANI composite.