[8p-C14-1~7] 6.5 Surface Physics, Vacuum

▲ [8p-C14-4] Fabrication of QCM sensor based on graphene oxide/TiO₂ nanocomposite for the detection of gases at room temperature

〇(M2)Pramudi Savidya Jayawardena¹, Hirulak Dilshan Siriwardena², Atsushi Kubono^1,2, Masaru Shimomura^1,2 (1.GSIST,Shizuoka Univ., 2.GSST,Shizuoka Univ.)

Keywords:gas sensor, Graphene, Quartz crystal microbalance

The aim of this study is to construct a room temperature gas sensor based on quartz crystal microbalance (QCM) containing graphene oxide (GO) / TiO₂ composite sensor layers. GO was obtained by modified Hummers method. TiO₂ were deposited in aqueous GO solution using liquid phase deposition technique. The composite was spin coated on the gold-plated QCM resonator and the sensing performance of functionalized QCM resonators was examined with GO, TiO₂ and GO/TiO₂ composite of different GO ratios at room temperature. The preliminary results denoted that GO/TiO₂ composite has a significant response to EtOH over GO and TiO₂ individually. Among composites of different GO ratios, most favourable sensitivity was obtained for 30% GO (w/w) in the precursor solution. Upon exposure to acetone, toluene, acetonitrile, chloroform and ammonia gases, highest response was obtained by ammonia whereas lowest was shown by toluene gas. SEM, TEM and XRD characteristic data of the composite revealed the formation of anatase TiO₂ on GO sheets through bridging and wrapping of the particles. According to XPS and EDX, during LPD of TiO₂ on GO, concurrently somewhat of fluorine and boron have also bonded to the composite. This may be the reason for obtaining the most favorable composite as 30% GO (w/w) in the precursor solution even though 50% GO (w/w) showed the highest surface area according to BET isotherm.