TY - JOUR

T1 - Electrically Conducting Nanocomposites of Carbon Nanotubes and Metal-Organic Frameworks with Strong Interactions between the two Components

AU - Schulze, Hendrik A.

AU - Hoppe, Bastian

AU - Schäfer, Malte

AU - Warwas, Dawid P.

AU - Behrens, Peter

N1 - Funding information: This work profited from funding by the DFG through the Cluster of Excellence EXC 1077 “Hearing4all”. Hendrik A. Schulze thanks the “Studienstiftung des deutschen Volkes” for a fellowship. We also like to thank Katharina Nolte and Dennes Nettelroth for thermogravimetric analysis, Mandy Jahns and Alexander Mohmeyer for physisorption measurements and the Laboratory of Nano and Quantum Engineering (LNQE) for the possibility to perform TEM measurements.

PY - 2019/9/3

Y1 - 2019/9/3

N2 - Highly integrated nanocomposites of Zr-based metal-organic frameworks (MOFs) of the UiO-66 class and multi-wall carbon nanotubes (MWCNTs) are prepared by direct crystallization of MOFs in the presence of CNTs. Powder samples with homogeneously distributed and strongly intergrown nanotubes and nanoparticles are obtained. Growth of the MOFs in the presence of CNTs deposited on glass slides yields open or compact coatings of the nanocomposites. The materials combine the high porosity and versatility of MOFs with the high electrical conductivities of CNTs. Upon increasing the amount of CNTs in the synthesis, the electrical conductivity shows a clear percolation behavior. Even with small amounts of CNTs, high conductivities are observed. SEM and TEM pictures show the strong intergrowth between the CNTs and the MOF nanoparticles. Crystallization times are shorter in the presence of CNTs, and CNTs run centrally through the MOF crystals. These facts indicate that the CNTs serve as heterogeneous nucleation centers for the formation of MOF nanocrystals. Sensing experiments performed on the coatings show significant changes in the electrical conductivities of the nanocomposite materials in the presence of different analytes, which are also discernable from the changes observed on bare CNTs. This is further proof for the close interaction between the components of the nanocomposites.

AB - Highly integrated nanocomposites of Zr-based metal-organic frameworks (MOFs) of the UiO-66 class and multi-wall carbon nanotubes (MWCNTs) are prepared by direct crystallization of MOFs in the presence of CNTs. Powder samples with homogeneously distributed and strongly intergrown nanotubes and nanoparticles are obtained. Growth of the MOFs in the presence of CNTs deposited on glass slides yields open or compact coatings of the nanocomposites. The materials combine the high porosity and versatility of MOFs with the high electrical conductivities of CNTs. Upon increasing the amount of CNTs in the synthesis, the electrical conductivity shows a clear percolation behavior. Even with small amounts of CNTs, high conductivities are observed. SEM and TEM pictures show the strong intergrowth between the CNTs and the MOF nanoparticles. Crystallization times are shorter in the presence of CNTs, and CNTs run centrally through the MOF crystals. These facts indicate that the CNTs serve as heterogeneous nucleation centers for the formation of MOF nanocrystals. Sensing experiments performed on the coatings show significant changes in the electrical conductivities of the nanocomposite materials in the presence of different analytes, which are also discernable from the changes observed on bare CNTs. This is further proof for the close interaction between the components of the nanocomposites.

KW - carbon nanotubes

KW - composites

KW - electrical conductivity

KW - metal-organic frameworks

KW - sensing

UR - http://www.scopus.com/inward/record.url?scp=85068522413&partnerID=8YFLogxK

U2 - 10.1002/cnma.201900110

DO - 10.1002/cnma.201900110

M3 - Article

AN - SCOPUS:85068522413

VL - 5

SP - 1159

EP - 1169

JO - ChemNanoMat

JF - ChemNanoMat

SN - 2199-692X

IS - 9

ER -