Room temperature operated carbon dioxide sensor based on silver doped zinc oxide/cupric oxide nanoflowers

Abstract

High operating temperature is needed for metal oxide based carbon dioxide sensor to attain good sensitivity but that will deteriorate the sensor performance over time. In order to overcome this challenge herein we demonstrated room temperature operated silver doped zinc oxide/cupric oxide nanoflowers based carbon dioxide sensor. Various concentration (1–5 wt%) of silver was doped on zinc oxide/cupric oxide nanoflowers grown over the zinc oxide seed layer by hydrothermal method. Analysis such as Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy were carried out to assess the crystallite size, chemical composition, morphology and crystal structure of the nanoflowers. The performance of the synthesized nanoflowers was investigated at room temperature (25 °C) by purging the carbon dioxide gas in the range of 150–1000 ppm inside the testing chamber. Zinc oxide/cupric oxide nanoflowers doped with 2 wt% of silver exhibits the high sensing response of 18.4% (1000 ppm) and excellent sensitivity of 0.0117% ppm−1 with response and recovery time in order of few minutes. In addition, the fabricated sensor exhibited better repeatability and selectivity under various humidity conditions and interference gases.