Zn mixed CeO2 nanoparticles: Enhancement of NO2 gas sensing performance

Abstract

Nitrogen dioxide (NO2) is highly noxious and detrimental to both human health and the natural environment, making it imperative to create a sensor capable of detecting NO2 gas. In this paper, we demonstrate the fabrication of zinc mixed cerium oxide (CZ) nanoparticles (NPs) sensor using a simple chemical route. The compositional, structural, morphological, and gas sensing characteristics of prepared Zn mixed CeO2 (CZ) NPs (with Zn content ranging from 1to 5 wt%) were investigated by various characterization techniques. The as-prepared Zn mixed CeO2 NPs (CZ) exhibited cubic crystal structure. The CeO2 nanoparticles mixed with 5 wt% Zn (CZ5 NPs) exhibited a larger surface area of m58.90 m2/g. The Zn (5 wt%) mixed CeO2 nanoparticles sensor achieved a remarkable maximum sensing response of 91.31% to 100 ppm and 5.53% to 1 ppm NO2 at a working temperature of 150 °C. The sensor demonstrated excellent reproducibility, with a rapid response time of 14.20 seconds and a recovery time of 350.65 seconds, along with notable stability at 89.80%. The remarkable response of porous Zn (5 wt%) mixed CeO2 NPs to NO2 can be attributed to their unique porous structure and the synergistic effect of Zn and CeO2, which together provide a substantial specific surface area, along with the presence of oxygen vacancies within the sensing material. Impedance and X-ray photoelectron spectroscopy (XPS) were employed to explore the potential NO2 sensing mechanism of the Zn (5 wt%) mixed CeO2 sensor.