High-performance LPG sensing behaviour of CoCr_2-xCe_xO₄ (x = 0 to 0.02) for sensor applications

For the first time, the influence of Cerium (Ce³⁺) on the structural, microstructural, Fourier infrared spectroscopy, and LPG sensing behaviour of CoCr_2-xCe_xO₄ (CoCrCe) is described in this study. The solution combustion technique was used to create the CoCrCe samples. All samples were sintered for 3 h at 600 °C to achieve a pure crystalline nature free of impurities. The production of cubic spinel structures with typical crystallite sizes smaller than 16 nm is confirmed by X-ray diffraction. Because compressive lattice strain is created when Ce³⁺ ions are replaced by Cr³⁺ ions, we discovered reducing the lattice parameter. Further samples were analysed using the FTIR technique to learn about the octahedral and tetrahedral stretching bands, which confirmed the ferrite structure was free of impurities. Scanning Electron microscopy was used to examine the samples' microstructures. All of the samples were determined to be very porous. Elemental analysis was performed using energy dissipative spectra, which confirmed the presence of all elements in the samples. 2-mol% Ce³⁺ has the best gas sensing characteristics of any Ce concentration. Furthermore, the thin film based on CoCr_1.98Ce_0.02O₄ may be employed as a chemiresistive gas sensor to detect LPG (10-1000 ppb) at room temperature. On LPG exposure, the constructed gas sensor demonstrates greater gas sensitivity in the order of 98% at 500 ppb, with higher stability, rapid response, and recovery time in the order of 60 s and 75 s, respectively. This study reports for the first time on the creation of an LPG gas sensor device that operates at room temperature and has high sensitivity. Because of their high gas sensitivity, rapid reaction and recovery times, and long-term stability, these material gas sensors might be ideal materials for the manufacture of gas sensors devices for the detection of LPG low concentration (ppb level).