Design of conjugated microporous polymer nanotubes for efficient benzene molecular adsorptions

International Journal of Quantum Chemistry

4 years ago

Design of conjugated microporous polymer nanotubes for efficient benzene molecular adsorptions

Yu-Cai Hu, Hua Shi, Wen-Jie Fan, Rui-Qin Zhang, Da-Zhi Tan, Yan-Ling Zhao

Single-walled conjugated microporous polymer (CMP) nanotubes containing alternative phenylene and ethynylene units were described computationally for the first time in this work. The electronic structures and adsorption properties were studied by the density-functional tight-binding method augmented with a van der Waals dispersion term. Our calculations show that the morphology of CMP influences the benzene-adsorption performance significantly. The tubes show smaller binding energies to benzene molecule than the film counterparts, consistent with the observation of low adsorption capacities of tubular materials in our experiments. Enlarging the linker or adding substituents in the node can both reduce the tube's band gap. The introduction of OH or NH2 substituents in the tube node increases the binding strength between the adsorbent and the adsorbate, which is energetically favorable to enhance the adsorption capacity. Our results are expected to provide theoretical insights into the rational design of novel CMP nanotubes with improved adsorption capacities for organics. Conjugated microporous polymer (CMP) nanotubes are a novel kind of organic tubular materials reported recently. The morphology (nanofilm and nanotube) of CMP networks affects its benzene-adsorption properties significantly. Enlarging the linker or adding substituents in the tube node can both reduce the electronic band gap of the tubes and noticeably change the binding strength between the nanotubes and the adsorbate.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/qua.25492