title: Monolayer Co3 O4 Inverse Opals as Multifunctional Sensors for Volatile Organic Compounds.
abstract: Monolayers of periodic porous Co3 O4 inverse opal (IO) thin films for gas-sensor applications were prepared by transferring cobalt-solution-dipped polystyrene (PS) monolayers onto sensor substrates and subsequent removal of the PS template by heat treatment. Monolayer Co3 O4 IO thin films having periodic pores (d≈500 nm) showed a high response of 112.9 to 5 ppm C2 H5 OH at 200 °C with low cross-responses to other interfering gases. Moreover, the selective detection of xylene and methyl benzenes (xylene+toluene) could be achieved simply by tuning the sensor temperature to 250 and 275 °C, respectively, so that multiple gases can be detected with a single chemiresistor. Unprecedentedly high ethanol response and temperature-modulated control of selectivity with respect to ethanol, xylene, and methyl benzenes were attributed to the highly chemiresistive IO nanoarchitecture and to the tuned catalytic promotion of different gas-sensing reactions, respectively. These well-ordered porous nanostructures could have potential in the field of high-performance gas sensors based on p-type oxide semiconductors.
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea.
authors.forename: Chul-Soon
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Kyoto University, Yoshidahonmachi, Sakyo Ward, Kyoto, 606-8501, Japan.
authors.forename: Zhengfei
authors.initials: Z
authors.lastname: Dai
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea.
authors.forename: Seong-Yong
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Kwak
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea.
authors.forename: Bo-Young
authors.initials: BY
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea.|Department of Materials Science Engineering, Research Institute of Advanced Materials, Seoul National University, 1, Gwanak-ru, Gwanak-gu, Seoul, 08826, Korea.
authors.forename: Do Hong
authors.initials: do H
authors.lastname: Kim
authors.affiliation: Department of Materials Science Engineering, Research Institute of Advanced Materials, Seoul National University, 1, Gwanak-ru, Gwanak-gu, Seoul, 08826, Korea.
authors.forename: Ho Won
authors.initials: HW
authors.lastname: Jang
authors.affiliation: Smart Convergence Sensor Research Center, Korea Electronics Technology Institute, 25, Saenari-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13509, Korea.
authors.forename: Joon-Shik
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Korea. jongheun@korea.ac.kr.
authors.forename: Jong-Heun
authors.initials: JH
authors.lastname: Lee
keywords: monolayers; nanostructures; sensors; template synthesis; thin films