Cobalt-doped praseodymium ortho ferrite as a promising nanomaterial for carbon dioxide gas sensing

Abstract

The rising level of carbon dioxide (CO₂) gas harms both the environment and people and also causes climate change and global warming. Thus, its detection is essential for critical health issues and environmental safety. In this study, pure and cobalt (Co)-doped praseodymium orthoferrite (PrFeO₃) nanomaterials were prepared by the sol–gel auto-combustion route. Field emission scanning electron microscopy (FESEM), and powder X-ray diffraction (PXRD) were used to investigate the surface morphology and crystal structure. Vibrational studies were carried out by Fourier transform infrared (FTIR) spectroscopy. Optical characteristics were investigated by ultraviolet-visible (UV-Vis) spectroscopy. Pure and co-doped PrFeO₃ nanomaterials in thin film form were explored for the first time to design a CO₂ gas sensor working at room temperature. To study the effect of cobalt doping on sensor performance, comparative gas sensing tests were performed on both pristine and Co-doped PrFeO₃ thin films. The study indicates that the Co-doped PrFeO₃ sensor has a higher response and shorter recovery and response times than the pristine PrFeO₃ sensor. At 500 ppm CO₂, the response time of PrFe_0.9Co_0.1O₃ is 17.2 s, while the recovery time is 18.4 s.