NiO-SiO_2 Sol-Gel Nanocomposite Films for Optical Gas Sensor

摘要

Recently nanocomposites with sensoring function are becoming a new area of intereat in the field of optical gas sensor.In fact,the optical transmittance of nano-particles or thin films has been reported to be changed by atmosphere gases.In particular it was found that NiO,Co_3O_4 and Mn_3O_4 thin films showed reversible decrease in the Vis-NIR absorption due to CO.Aim of this work is the syntesis and the characterization of SiO_2 sol-gel glass films deped with NiO nanocrystals.Films of composition (100-X) SiO_2-XNiO with X=10,20,40,were obtained by mixing a matrix solution of Si(OC_2H_5)_4 (TEOS) and CH_3Si(OC_2H_5)_3 (MTES) as SiO_2 precursors,with a doping solution containing NiCl_2 as precursor for NiO particles.3-Aminopropyltriethoxysilne (3-APTES),bearing either an ammine group capable of coordination ghe Ni ions and hydrolysable siloxane groups for anchoring the metal xomplex moiety to the silicate mitrox,was used as sifunctional ligand.