In Situ Coupling of Multidimensional MOFs for Heterogeneous Metal-Oxide Architectures: Toward Sensitive Chemiresistors

Ji-Soo Jang; Won-Tae Koo; Dong-Ha Kim; Il-Doo Kim

doi:10.1021/acscentsci.8b00359

In Situ Coupling of Multidimensional MOFs for Heterogeneous Metal-Oxide Architectures: Toward Sensitive Chemiresistors

ACS Cent Sci. 2018 Jul 25;4(7):929-937. doi: 10.1021/acscentsci.8b00359. Epub 2018 Jun 29.

Authors

Ji-Soo Jang^{1

2}, Won-Tae Koo^{1

2}, Dong-Ha Kim^{1

2}, Il-Doo Kim^{1

2}

Affiliations

¹ Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
² Advanced Nanosensor Research Center, KI Nanocentury, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.

Abstract

Metal-organic frameworks (MOFs) are used as a new intriguing class of templates, which enable the creation of porous inorganic nanostructures via calcination. In this work, we first introduce in situ coupling of multidimensional MOFs for producing heterogeneous metal-oxide composite with multiple p-n junctions. Controlling relative ratios of two mixed solvents (water and ethanol), in zeolitic imidazolate framework (ZIF) growth, leads to the distinctive morphological evolution such as rod, sheet, and polyhedron particles. One-pot hybridization of ZIF-8 (sheet) with ZIF-67 (rods) results in the generation of hierarchically assembled 1D ZIF-67 rods anchored on a 2D ZIF-8 sheet. Through the calcination of such hybridized ZIFs, we successfully prepared hierarchically assembled 1D Co₃O₄ rods immobilized in a 2D ZnO sheet, possessing numerous n-type ZnO/p-type Co₃O₄ heterogeneous interfaces. This unique structure offers a remarkably enhanced chemiresistive sensing performance (R_a/R_g = 29 at 5 ppm acetone).