Co₃O₄ nanoparticle-attached SnO₂ nanowires are synthesized to fabricate highly sensitive acetone gas sensor by vapor-liquid-solid (VLS), sol-gel, and thermal annealing processes. To analyze enhanced acetone gas sensing responses, Co₃O₄ nanoparticles are attached SnO₂ nanowires, and several samples are synthesized followed by the cycles of Co₃O₄ nanoparticle attachment process. The sensing response of Co₃O₄ nanoparticle-attached SnO₂ nanowires, which are one time performed Co₃O₄ nanoparticle attachment process, is improved by 7 times compared with as-synthesized SnO₂ nanowires when exposed to 50 ppm acetone gas. In particular, when exposed to 0.5 ppm acetone gas, as-synthesized SnO₂ nanowires present an extremely low response — close to negligible. However, when Co₃O₄ nanoparticles are attached, the response is improved drastically. Furthermore, the sensing selectivity toward acetone gas is improved compared with its counterpart. This improved sensing property is derived from the increasing variation in the surface depletion area located in the p-n heterojunction.

通过汽-液-固（VLS），溶胶-凝胶和热退火工艺，合成了附着有Co ₃ O ₄纳米粒子的SnO ₂纳米线，以制造高灵敏度的丙酮气体传感器。为了分析增强的丙酮气体感测响应，将Co ₃ O ₄纳米粒子附着到SnO ₂纳米线上，并合成几个样品，然后循环进行Co ₃ O ₄纳米粒子附着过程。一次执行Co ₃ O ₄的附着Co ₃ O ₄纳米粒子的SnO ₂纳米线的感测响应当暴露在50 ppm的丙酮气体中时，纳米粒子的附着过程比合成后的SnO ₂纳米线提高了7倍。特别是，当暴露于0.5 ppm的丙酮气体中时，合成后的SnO ₂纳米线表现出极低的响应-几乎可以忽略不计。然而，当附着Co ₃ O ₄纳米颗粒时，响应大大改善。此外，与丙酮气体相比，对丙酮气体的感测选择性得到了改善。这种改善的感测特性源自位于pn异质结中的表面耗尽区的变化增加。