title: Nanoscale PdO Catalyst Functionalized Co3O4Hollow Nanocages Using MOF Templates for Selective Detection of Acetone Molecules in Exhaled Breath.
abstract: The increase of surface area and the functionalization of catalyst are crucial to development of high-performance semiconductor metal oxide (SMO) based chemiresistive gas sensors. Herein, nanoscale catalyst loaded Co3O4hollow nanocages (HNCs) by using metal-organic framework (MOF) templates have been developed as a new sensing platform. Nanoscale Pd nanoparticles (NPs) were easily loaded on the cavity of Co based zeolite imidazole framework (ZIF-67). The porous structure of ZIF-67 can restrict the size of Pd NPs (2-3 nm) and separate Pd NPs from each other. Subsequently, the calcination of Pd loaded ZIF-67 produced the catalytic PdO NPs functionalized Co3O4HNCs (PdO-Co3O4HNCs). The ultrasmall PdO NPs (3-4 nm) are well-distributed in the wall of Co3O4HNCs, the unique structure of which can provide high surface area and high catalytic activity. As a result, the PdO-Co3O4HNCs exhibited improved acetone sensing response (Rgas/Rair= 2.51-5 ppm) compared to PdO-Co3O4powders (Rgas/Rair= 1.98), Co3O4HNCs (Rgas/Rair= 1.96), and Co3O4powders (Rgas/Rair= 1.45). In addition, the PdO-Co3O4HNCs showed high acetone selectivity against other interfering gases. Moreover, the sensor array clearly distinguished simulated exhaled breath of diabetics from healthy people's breath. These results confirmed the novel synthesis of MOF templated nanoscale catalyst loaded SMO HNCs for high performance gas sensors.
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Won-Tae
authors.initials: WT
authors.lastname: Koo
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Sunmoon
authors.initials: S
authors.lastname: Yu
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Seon-Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Ji-Soo
authors.initials: JS
authors.lastname: Jang
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Cheong
authors.affiliation: Department of Materials Science and Engineering, and ‡Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Il-Doo
authors.identifier: http://orcid.org/0000-0002-9970-2218
authors.initials: ID
authors.lastname: Kim
mesh_terms: D000096:Acetone / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt; D005740:Gases; D053768:Metal Nanoparticles; D010087:Oxides; D010165:Palladium
chemical_list: D005740:Gases; D010087:Oxides; D000096:Acetone; D003035:Cobalt; D010165:Palladium; C048320:palladium oxide; C060728:cobalt oxide
keywords: ZIF-67; catalyst; gas sensors; metal oxide; metal−organic framework