Benseghir Youven, Tsang Min Ying, Schöfbeck Flora, Hetey Daniel, Kitao Takashi, Uemura Takashi, Shiozawa Hidetsugu, Reithofer Michael R, Chin Jia Min
Institute of Functional Materials and Catalysis, Faculty of Chemistry, University of Vienna, Währinger Str. 42, 1090 Vienna, Austria.
Institute of Functional Materials and Catalysis, Faculty of Chemistry, University of Vienna, Währinger Str. 42, 1090 Vienna, Austria; Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Str. 42, 1090 Vienna, Austria.
J Colloid Interface Sci. 2025 Jan 15;678(Pt A):979-986. doi: 10.1016/j.jcis.2024.08.221. Epub 2024 Aug 30.
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.
金属有机框架（MOF）材料的精确沉积对于制造高性能的基于MOF的器件至关重要。通过电场辅助将聚（3,4-亚乙基二氧噻吩）功能化（PEDOT）的MIL-101（Cr）纳米颗粒滴铸到叉指电极上，使其能够在电极间隙中作为渗流纳米颗粒链进行精确的空间选择性沉积。对所得的排列材料进行了电阻式和电容式湿度传感研究，并与通过常规滴铸制备的未排列样品进行了比较。MOF的空间选择性沉积在电阻式湿度传感过程中使电导率提高了多达500倍以上，响应度提高了约6倍。排列的样品还表现出良好的电容式湿度传感性能，在相对湿度为10%与90%时，电容增益高达310倍。相比之下，未排列样品的电阻行为使其不适用于电容传感。这项工作表明，在滴铸过程中施加交变电势是一种简单而有效的方法，可控制MOF沉积，以提高效率、电导率并增强湿度传感性能。
