Pristine and palladium-doped perovskite bismuth ferrites and their nitrogen dioxide gas sensor studies

Abstract

Undoped and palladium-doped perovskite bismuth ferrite nitrogen dioxide (NO2) gas sensors (BiFeO3 i.e. BFO and Pd-BiFeO3 i.e. Pd-BFO) are successfully synthesized via an easy and low-cost sol–gel process. The Pd-doping in BFO is confirmed through an X-ray diffraction data, field emission scanning electron microscopy images, energy-dispersive X-ray spectroscopy analysis, and its influence on the structure, morphology, surface area, and the NO2 gas sensor performance of the BFO sensor has been examined and explored. Moreover, the plausible gas sensing response mechanism of Pd-BFO film sensor has also been proposed. The nanocubes embedded into a uniformly distributed upright standing nanoplates facilitate better gas adsorption and diffusion behavior on providing an excellent NO2-sensing performance with good sensitivity, excellent selectivity, better response (90 s)/recovery (110 s), and noticeable repeatability under a fixed 100 ppm NO2 gas concentration level at an optimized low operating temperature i.e. 150 °C.

Keywords

• BiFeO3 and Pd-BiFeO3
• NO2 gas sensors
• Sol–gel synthesis
• Structural elucidation
• Dual surface morphology