Development of Low-ppm CO Sensors Using Pristine CeO₂ Nanospheres with High Surface Area

Abstract

Mesoporous CeO₂ nanospheres with appreciably high surface area are prepared using reversed micelles by a water-in-oil microemulsion method. The structural morphology and semiconducting properties of the nanoparticles are thoroughly investigated using X-ray diffraction, field effect scanning electron microscopy, transmission electron microscopy, and UV-visible spectroscopic techniques. Even after high-temperature calcination, the morphological retention of the material is apparent by electron microscopy. The deployment of undoped CeO₂ nanospheres for the detection of low-ppm CO yields superior performances in terms of sensitivity, response-recovery times, and selectivity compared to those of other sensors of the same genre. These CO sensors exhibit ∼ 52% sensitivity with a response time of only 13 s. The sensor parameters are analyzed as a function of both temperature and gas concentration. In addition to that on the cost-effective and scalable synthesis of CeO₂ nanospheres, this article also reports on the fabrication of packaged CO sensors, which can be potentially utilized for industrial and environmental monitoring purposes.