Synthesis, characterisation and sensing properties of Sm₂O₃ doped SnO₂ nanorods to C₂H₂ gas extracted from power transformer oil

Abstract

In this paper, pure and 1.5, 2.5 and 3.5 at.-% samarium oxide (Sm₂O₃) doped tin oxide (SnO₂) nanorods were successfully synthesised with a facile and environment friendly hydrothermal process. All the as prepared nanostructures were carefully characterised by X-ray diffraction, field emission SEM, TEM, high resolution TEM and X-ray photoelectron spectroscopy respectively. Planar sensors were further fabricated with the as synthesised samples, and their sensing properties towards acetylene gas (C₂H₂), an extremely significant fault characteristic gas dissolved in oil immersed power transformers, were systematically measured. Interestingly, the sensing properties of the fabricated SnO₂ nanorod based sensor to C₂H₂ gas can be obviously enhanced by adding Sm₂O₃, and the sensor doped with 3.5 at.-%Sm₂O₃ displays the most superior sensing characteristics, including operating temperature, sensitivity, response and recovery time, etc., as compared to other three cases. All results indicate that the synthesised Sm₂O₃ doped SnO₂ sensing material might be a promising candidate for C₂H₂ sensing and lay a solid foundation for exploring high performance chemical gas sensor to detect C₂H₂ gas extracted from power transformer oil.

Keywords:

• Hydrothermal synthesis
• Structural characterisation
• SnO₂ nanorods
• Sm₂O₃
• C₂H₂ sensing properties