Electrospun Ce-doped SnO2 and ZnO hollow nanofibers and their gas sensing applications

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T S Natarajan, P Mohanapriya and Swagato Sarkar

Indian Institute of Technology Tirupati, India
Indian Institute of Technology Madras, India

: J Nanomater Mol Nanotechnol

Abstract

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Electrospinning is a simple, inexpensive and versatile method for producing nanofibers from their corresponding solutions with high aspect ratio, flexibility and high tensile strength. Nanofibers in addition provide large surface area to volume ratio which is also attractive for sensing applications. Pure SnO2, which is in general n-type semiconductors, is limited in gas sensing applications due to its low sensitivity, slow response and lack of selectivity. However, doping with Ce has improved the sensing performance and has shown a high selectivity to ethanol. Obtained fibers were in the form of hollow tubes with diameters in the range of 110-200 nm as shown in Figure 1. All hollow nanofibers (pure and Ce-doped SnO2 with 3, 6 and 9 mol%) exhibit high sensitivity and good repeatability to ethanol at 250°C. Among them, the 6 mol% Ce-doped SnO2 hollow fibers shows the highest sensor response to ethanol, the same sample shows the highest sensor response to toluene at 350°C. Also, Ce-doped ZnO hollow nanofibers with different doped Ce ratios (3, 6 and 9 mol%) are synthesized by an Electrospinning method using zinc acetate dihydrate and cerium(III) nitrate hexahydrate as starting materials and DMF as solvent. The simple low cost gas sensor is made with electrodes of aluminium and gas sensing properties are tested for methane gas at room temperature. The sensitivity has increased when the concentration of the gas is increased, but the response time remains almost equal. The results obtained in this study indicate that both SnO2-CeO2 and ZnO-CeO2 nanofiber composites are potential candidates for use as high sensitivity gas sensors.

Biography

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Email: tsniit@iittp.ac.in