Unraveling the potential of Gd doping on mullite Bi2Fe4O9 for fiber optic ethanol gas detection at room temperature

Development of multiferroic materials is gaining importance due to its potential multifunctional properties, in addition to their non-toxicity and cost effectiveness. Herein, the gas sensing properties of multiferroics at room temperature (RT) would serve to overcome the limitations in volatile gas sensing for industrial applications, due to their rapid response, recovery time and their high chemical inertness. In this study, conventional solid state ball milling technique was employed to synthesize pristine Bi2Fe4O9 (BFO) and Gadolinium doped Bi2Fe4O9 (BGFO). X-ray diffraction study (XRD), Raman spectra and X-ray photo-electron spectroscopy (XPS) analysis confirmed that Gadolinium (Gd) ions were incorporated into the Bi site of the orthorhombic BFO lattice without altering the structure. Further, optical analysis showed enhanced absorption and improved conduction respectively with narrow band gap, in particular for BGFO3 (3% (w/w) Gd doped BFO) sample, which is in good agreement with electronic study. Importantly, clad modified fiber optic gas sensing study inferred superior ethanol gas sensing (0–500 ppm) at room temperature for BGFO3 compared to BFO with high sensitivity (%); quick response and recovery period of about 38 s and 67 s respectively. All these results emphasize on RT multifunctional properties of Gd doped BFO with a spiked ethanol gas sensing ability suited for industrial applications. •Gadolinium doped Bi2Fe4O9, (BGFO3) synthesized – ball milling method.•Improved conduction in BGFO3- confirmed by Narrow band gap.•Clad modified BGFO3 – Fiber optic gas sensor.•Increased Sensitivity (%) for Ethanol-rapid response (38 s) and recovery time (67 s).•BGFO3, a potential multiferroic oxide for ethanol sensing in industrial applications.