Design of Ce incorporated tricobalt tetroxide Co₃O₄ sensor with boosted gas sensing performance toward nitrogen dioxide

Cerium-doped tricobalt tetroxide (Ce-Co₃O₄) has been successfully synthesized via a simple hydrothermal route. The structural, morphological, and elemental compositions of prepared samples with their corresponding chemical states were analyzed by employing X-ray diffraction (XRD), field emission scanning microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS) respectively. The gas sensing measurement of the prepared samples reveals the superior gas sensing performance of 1 at.% Ce-doped Co₃O₄ microflowers with an excellent response of 35% toward 50 ppm of NO₂ at near room temperature of 50 ℃. The proposed sensor exhibits outstanding stability of 99% over a period of a month. The repeatability of the sensor for five consecutive cycles reveals the ability of the proposed sensor for the potential NO₂ sensing application. Moreover, the limit of detection (LoD) of the sensor is found to be as low as 4500 ppb. The reason behind the enhanced sensing performance of the fabricated sensor and the possible mechanism has been discussed in the present study.