Facile strategy to synthesize donut-shaped α-Fe2O3 nanoparticles for enhanced LPG detection

Donut-shaped hematite (alpha-Fe2O3) nanoparticles were synthesized using facile chemical colloidal method for the development of high performance LPG gas sensor. Herein, the annealing temperature was used as a tool to regulate the morphology of nanoparticles from non-uniform elongated solid nanoparticles to donut-shaped structures. The structural variations as a function of annealing temperature characterized using high energy synchrotron X-Ray Diffraction and selected area electron diffraction determines preferential orientation of nanoparticles along (104) plane. Owing to its large surface area and porosity, the sensor with donut-shaped morphology exhibited outstanding response enabling efficient detection of LPG gas with concentration as low as 10 ppm at operating temperature 170 degrees C. The systematic gas sensing experiments performed periodically also demonstrates fast response/recovery, high stability and excellent repeatability towards LPG gas. In addition, the possible sensing mechanism of alpha-Fe2O3 nanoparticles based gas sensor towards the LPG gas has been discussed.