Efficient detection of 45 ppb ammonia at room temperature using Ni-doped CeO 2 octahedral nanostructures

• Published in: Journal of colloid and interface science 2024-05, Vol.662, p.663
• Main Authors: Paul, Rinku, Maity, Nikhilesh, Das, Biswajit, Emadian, Seyedeh Sadrieh, Kumar, Ajay, Krishnamurthy, Satheesh, Singh, Abhishek Kumar, Ghosh, Ranajit
• Format: Article
• Language: English
• ISSN: 1095-7103

To meet the requirements in air quality monitors for the public and industrial safety, sensors are required that can selectively detect the concentration of gaseous pollutants down to the parts per million (ppm) and ppb (parts per billion) levels. Herein, we report a remarkable NH sensor using Ni-doped CeO octahedral nanostructure which efficiently detects NH as low as 45 ppb at room temperature. The Ni-doped CeO sensor exhibits the maximum response of 42 towards 225 ppm NH , which is ten-fold higher than pure CeO . The improved sensing performance is caused by the enhancement of oxygen vacancy, bandgap narrowing, and redox property of CeO caused by Ni doping. Density functional theory confirms that O vacancy with Ni at Ce site (V Ni ) augments the sensing capabilities. The Bader charge analysis predicts the amount of charge transfer (0.04 e) between the Ni-CeO surface and the NH molecule. As well, the high negative adsorption energy (≈750 meV) and lowest distance (1.40 Å) of the NH molecule from the sensor surface lowers the detection limit. The present work enlightens the fabrication of sensing elements through defect engineering for ultra-trace detection of NH to be useful further in the field of sensor applications.