SnO_2, SnO_2:Mg and SnO_2:Ni Nanoparticles Based Luminescence Ammonia Sensors

摘要

Among the different nanostructured oxide materials, the n type tin oxide is most commonly used for gas sensing preferably for low ppm ammonia sensing. The doping of metal makes the materials more suitable for such applications. In present work, pure SnO_2 and Sn_(1_x)A_xO_2 (A = Ni and Mg, X- 0.07) nanoparticles have been successfully synthesized via sol-gel process by using ethanol as solvent. Then synthesized samples were analyzed using X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM) with Energy-dispersive X-ray spectroscopy (EDS), and Photoluminescence (PL) spectroscopy. The X-ray study reveals the crystalline nature of the nanoparticles under study and SEM images confirms the existence of very small, uniformly spherical and non-agglomerated nanoparticles. The crystallite size decreases when doped with Mg and Ni atoms. The PL study of the present nanoparticles has been obtained in the range 400-700 and the spectra obtained with emission in visible region around two distinguished wavelengths, blue (470 nm) and green (530 nm). The gas sensing was performed through photoluminescence spectrometer for different concentration of ammonia at room temperature. The response and recovery time of these samples are found to be in the range of 20-15 s and 53-30 s respectively.