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

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.