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

The rising level of carbon dioxide (CO 2 ) 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 (PrFeO 3 ) 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 PrFeO 3 nanomaterials in thin film form were explored for the first time to design a CO 2 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 PrFeO 3 thin films. The study indicates that the Co-doped PrFeO 3 sensor has a higher response and shorter recovery and response times than the pristine PrFeO 3 sensor. At 500 ppm CO 2 , the response time of PrFe 0.9 Co 0.1 O 3 is 17.2 s, while the recovery time is 18.4 s. A graphic abstract showing the sensing process of CO 2 gas by a thin film of cobalt-doped praseodymium ortho ferrite nanomaterial.