LPG Sensing Study of Calcium-Doped Praseodymium Orthoferrite Nanomaterial

Liquefied petroleum gas (LPG) is a modern fuel for kitchens, vehicles, and industry. Leakage of LPG is extremely fatal for humans and the atmosphere; therefore, quick detection is a vital need. The sol-gel self-combustion process was applied to synthesize the calcium-doped praseodymium orthoferrite (PrFeO₃) nanomaterials. Synthesized nanoparticles were analyzed by powder X-ray diffraction (PXRD) for phase and crystallite size, energy dispersive X-ray (EDX) for elemental composition and field emission scanning electron microscopy (FESEM) for surface morphology, high-resolution transmission electron microscopy (HR-TEM) for structural and morphology, ultraviolet-visible (UV-vis) spectroscopy for absorption behavior and energy band gap, Brunauer-Emmett-Teller (BET) for surface analysis, and Fourier transform infrared spectroscopy (FTIR) for the vibrational study. The PXRD illustrates that the crystallite size reduces from 27.72 to 20.49 with the rising content of calcium. The FESEM and EDX interpret the morphology and elemental composition/mapping. The UV-vis spectroscopy reveals that the band gap is decreasing from 2.25 to 1.87 eV with the increasing concentration of calcium. The optimized nanomaterials were explored for LPG sensing. Recovery time, response time, sensor response, etc., were determined and discussed. This study divulges that the composition Pr_0.8Ca_0.2FeO₃ has optimum sensor response, selectivity, and least response and recovery times of 7.5 and 7.1 s, respectively. The designed sensor shows good selectivity for LPG at ambient temperature. The current study points out that the developed sensor outperforms in terms of response and recovery times when compared with other LPG sensors based on perovskite materials. The gas sensing mechanism has been explained.