Electric-field assisted spatioselective deposition of MIL-101(Cr)<sub>PEDOT</sub> to enhance electrical conductivity and humidity sensing performance

Author(s)
Youven Benseghir, Min Ying Tsang, Flora Schöfbeck, Daniel Hetey, Takashi Kitao, Takashi Uemura, Hidetsugu Shiozawa, Michael R. Reithofer, Jia Min Chin
Abstract

Precise deposition of metal–organic framework (MOF) materials is important for fabricating high-performing MOF-based devices. Electric-field assisted drop-casting of poly(3,4-ethylenedioxythiophene)-functionalized (PEDOT) MIL-101(Cr) nanoparticles onto interdigitated electrodes allowed their precise spatioselective deposition as percolating nanoparticle chains in the interelectrode gaps. The resulting aligned materials were investigated for resistive and capacitive humidity sensing and compared with unaligned samples prepared via regular drop-casting. The spatioselective deposition of MOFs resulted in up to over 500 times improved conductivity and approximately 6 times increased responsivity during resistive humidity sensing. The aligned samples also showed good capacitive humidity sensing performance, with up to 310 times capacitance gain at 10 versus 90 % relative humidity. In contrast, the resistive behavior of the unaligned samples rendered them unsuitable for capacitive sensing. This work demonstrates that applying an alternating potential during drop-casting is a simple yet effective method to control MOF deposition for greater efficiency, conductivity, and enhanced humidity sensing performance.

Organisation(s)
Department of Functional Materials and Catalysis, Electronic Properties of Materials, Department of Inorganic Chemistry
External organisation(s)
University of Tokyo, Czech Academy of Sciences, Vienna Doctoral School in Chemistry (DoSChem)
Journal
Journal of Colloid and Interface Science
Volume
678
Pages
979-986
No. of pages
8
ISSN
0021-9797
DOI
https://doi.org/10.1016/j.jcis.2024.08.221
Publication date
01-2025
Peer reviewed
Yes
Austrian Fields of Science 2012
204001 Inorganic chemical technology, 205004 Functional materials, 104017 Physical chemistry
Keywords
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Biomaterials, Surfaces, Coatings and Films, Colloid and Surface Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/30eb4433-643d-4e30-890c-fcb5e1f338aa