A Highly Selective Room Temperature NH3 Gas Sensor based on Nanocrystalline a-Fe2O3

Sensors & Transducers

Priyanka A. PATIL¹  Vinita V. DEO¹  Lalchand A. PATIL¹  Dhanashri G. PATIL¹ 

[1] Nanomaterials Research Laboratory, Department of Physics Pratap College Amalner, Dist.: Jalgaon, Maharashtra, 425401, India;

关键词: a-Fe2O3;    Sol-gel;    NH3 sensing;    Room temperature;   

DOI  :  

来源: DOAJ

【 摘 要 】

Nanocrystalline a-Fe2O3 powder was synthesized by simple, inexpensive sol-gel method. The obtained powder was calcined at 700 0C in air atmosphere for 2 hours. The structural and morphological properties of calcined powder were studied by X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) respectively. Thermal properties of dried gel were studied by Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC). The XRD pattern of the powder confirmed the a-Fe2O3 (hematite) phase of iron oxide with average crystalline size of 30.87 nm calculated from Scherrer equation. The FESEM images showed uniform wormlike morphology of a-Fe2O3 powder. TGA result indicated that a-Fe2O3 is thermodynamically stable. Room temperature NH3 sensing characteristics of a-Fe2O3 were studied for various concentration levels (250-2500 ppm) of NH3 at various humid conditions. The sensor based on a-Fe2O3 exhibited good selectivity and excellent sensitivity (S=92) towards 1000 ppm of NH3 with quick response of 4 sec and fast recovery of 9 sec. Room temperature sensing mechanism is also discussed.

【 授权许可】

Unknown