Sensitivity enhancement of In2O3/ZrO2 composite based acetone gas sensor: A promising collaborative approach of ZrO2 as the heterojunction and dopant for in-situ grown octahedron-like particles

In the present work, the chemo-resistive acetone sensor based on n-n heterojunction was designed and fabricated by incorporating ZrO2 into one-dimensional In2O3 nanowires (NWs). The In2O3/ZrO2 (IZO) nanowires were synthesized via a facile electrospinning strategy followed by calcination. Interestingly, some in-situ grown octahedral-like particles appears on the surface of nanowires. It is observed that the In2O3/ZrO2 heterojunction exhibits a comparatively better response for 100-ppm acetone gas with a short response time of ~1 s at the operating temperature of 260 °C. The maximum sensitivity is obtained by optimizing the doping In/Zr molar ratio. Furthermore, several considerations are discussed to evaluate the sensitivity, selectivity, long-term stability (“3 S”), and repeatability. Overall, this work not only reveals the role of ZrO2 in the generation and resistance modulation of the n-n heterojunction but also provides a unique perspective on using ZrO2 to modulate lattice spacing to construct in-situ grown octahedral-like particles on In2O3 nanowires, thereby providing valuable guidance for optimizing the sensing performance of the In2O3 based composite sensors for sub-ppm-level acetone gas. [Display omitted] •The heterostructured In2O3/ZrO2 nanowires with in-situ grown octahedron-like particles were synthesized.•The sensor based on the IZO-3 sample exhibits an ultra-fast response time and superior selectivity to acetone gas.•The IZO-3 sensor can detect sub-ppm-level acetone 260 °C and provide an opportunity for the diabetes diagnosis.•The enhanced sensing behavior is ascribed to the synergy of charge transfer, resistance modulation, and porous structure.