NO2 sensing studies of bio-green synthesized Au-doped SnO2

Gold (Au) doped SnO 2 nanoparticles have been synthesized using remnant water (ideally kitchen waste) collected from soaked Bengal gram beans ( Cicer arietinum L.) extract. The synthesized nanoparticles were initially investigated for their structural, morphological and vibrational properties. The structural properties revealed rutile structure with narrow size distribution and average crystallite size of ~25 nm. The investigation using UV–Vis spectroscopy, and Raman spectroscopy indicated the formation of structural defects and oxygen vacancies due to bio-green synthesis and incorporation of Au in SnO 2 lattice. Subsequently, Au-doped biosynthesized SnO 2 nanoparticles were coated onto the glass substrate using doctor blade method to form thin films. These thin films were investigated for their gas sensing properties and were found to be highly sensitive to NO 2 at 200 °C operating temperature. The reported gas sensing results suggest that the biosynthesis of Au-doped SnO 2 is a promising method to fabricate low-cost SnO 2 based NO 2 sensor.