Nanofibers of Palladium (Pd)-sensitized SnO2 Encapsulated with Polyaniline for Effective Hydrogen Gas Sensing

Abstract: In this paper, we have successfully synthesized Pd-doped SnO2 nanofibers encapsulated with Polyaniline (PANI). The morphology of nanofibers was investigated using Scanning Electron Microscopy (SEM) technology. SEM study suggested that the diameter of Pd-doped SnO2 encapsulated with polyaniline (PSP) nanofibers was found in the range 200-400 nm. The average diameter of PSP nanofibers was estimated using ImageJ software. XRD study of pure FIBRESnO2 and PSP nanofibers shows perfect matching of major peaks corresponding to Tin Oxide (SnO2). EDAX pattern depicted weight percentage of constituent elements indicated the presence of Palladium (Pd) in nanofibers. The study revealed that PSP nanofibers were more sensitive as compared to pristine SnO2 nanofibers. The working temperature of PSP nanofibers was found 32°C. The low working temperature provokes the use of PSP nanofibers as a promising hydrogen gas sensor. Response and recovery time of 34 seconds and 63 seconds respectively has been observed for PSP nanofibers. Palladium (Pd) could have played a major role in higher response towards hydrogen gas sensing. The mesoporous PSP electrospun nanofibers exhibited excellent response and recovery behavior, with much higher sensitivity to H2 as compared with pure SnO2 nanofibers. It could be understood that the high gas sensing performance of PSP nanofibers is obtained from the high surface area, with more activity at Pd active sites of nanofibers. Highly porous nature of electrospun nanofibers led to effective surface interaction between the hydrogen gas molecules and SnO2 active site mediated by palladium for electron transfer through the matrix of nanofibers. Keywords: Nanofibers, Hydrogen sensing, Pd-doped SnO2 Polyaniline (PSP), Electrospinning, Polyaniline.