Gold sensitized sprayed SnO2 nanostructured film for enhanced LPG sensing

•Nanostructured SnO2 uniform, good quality deposition by spray pyrolysis.•Au sensitization was done by gold (Au) salt (0.001 M solution) by SPD method.•SnO2 film, Au-sensitized SnO2 film used for liquefied petroleum gas (LPG) sensing.•Au-sensitized SnO2 showed improved fast (60 s) LPG response 57% at 780 ppm.•Au electric and spillover effect mechanism for LPG sensing is studied.

We report LPG sensing of gold (Au)-sensitized SnO2 nanostructured film fabricated by an easy spray pyrolysis deposition method whose surface morphology is confirmed by field-emission scanning electron microscopy and atomic force microscopy images and structure by X-ray diffraction pattern. Energy dispersive X-ray spectrometer analysis has carried out for finding elemental composition. The SnO2 film is uniform and consists of spherical particles of ∼10 nm. The highest gas response observed at 780 ppm LPG concentration for pristine SnO2 is 28%, at operating temperature 623 K, which is greatly improved on Au sensitization up to 57% with 60 s rapid response time at 598 K operating temperarture. The high gas response is due to electronic effect and catalytic spill-over effect of Au sensitization. The improved sensing mechanism has throughly been explored .

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