Modulating the conductivity of microporous metal-organic frameworks (MOFs) through formulation of composites with graphene (G), as the conductive element, is demonstrated, without being limited to a particular MOF composition or topology. The synthesis allows for varying G content within the composite systematically, resulting in highly electrically conductive composites beyond 30 wt% G. The charge percolation model can effectively be utilized to describe the macroscopic electrical conductivity of the synthesized composites. Starting from a non-conductive MOF (HKUST-1, σ = 2*10−8 S m−1), enhanced conductivity can be accessed through increasing the G wt%, reaching more than nine orders of magnitude increase in conductivity up to 23.3 S m−1 for the composite containing 59.4 wt% G. A charge percolation threshold of 30 wt% G was observed, where sufficient G-G contacts were established within the composite. The ab initio DFT calculations on Cu-paddlewheel@G model indicated several non-covalent interactions, including OH⋯π and π‒π interactions, governing the deposition of the MOF on top of G (range of ‒101.3 kJ/mol to −113.8 kJ/mol). This approach is potentially transferable to the vast majority of MOFs, as surface functionalization of the conductive filler is not a prerequisite for the attainment of bottom-up assembly of the MOF@G.
|Original language||English (US)|
|Journal||Applied Materials Today|
|State||Published - Feb 26 2020|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-14
Acknowledgements: We acknowledge the financial support from Zewail City of Science and Technology (CMS-MA) and the support from Alexander von Humboldt foundation (MHA). AAM acknowledges the use of the resources of the Supercomputing laboratory at KAUST, Saudi Arabia.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Materials Science(all)