|
André Wolf, Vladimir Lesnyak, Sergei V. Voitekhovich, Nikolai Gaponik, Alexander Eychmüller
The assembly of nanoparticles into 1D, 2D and 3D structures open the opportunity to develop materials with well-defined properties. For instance, 3D assembly of nanoparticles in a gel network leads to highly porous structures which preserve the inherent properties of their building blocks. Typical methods used to produce hydrogels are ageing, chemical and photochemical treatments.[1] Processed by critical point drying, hydrogels form monolithic aerogels having high porosity and large surface area. We present a new type of 3D assembly achieved by interconnecting the nanoparticles capped by 5-mercaptomethyltetrazole via metal-tetrazole complexation.[2] This approach provided an efficient control of the optical properties and the morphology of the assemblies by varying their composition of metal and semiconductor nanoparticles in the gel.[3] Interconnection of the nanoparticles in the network ensures efficient charge and/or energy transfer. As an example of a fine tuning of the properties of the assemblies, in particular its photoluminescence, we demonstrate the fabrication of a white light emitting gel employing tetrazole capped ZnSe and CdTe quantum dots. [1] Gaponik, N.; Wolf, A.; Marx, R.; Lesnyak, V.; Schilling, K.; Eychmüller, A., Three-dimensional self-assembly of thiol-capped CdTe nanocrystals: gels and aerogels as building blocks for nanotechnology. Adv. Mater. 2008, 20, 4257-4262. [2] Lesnyak, V.; Voitekhovich, S. V.; Gaponik, P. N.; Gaponik, N.; Eychmüller, A., CdTe Nanocrystals Capped with a Tetrazolyl Analogue of Thioglycolic Acid: Aqueous Synthesis, Characterization, and Metal-Assisted Assembly. ACS Nano 2010, 4, 4090-4096. [3] Lesnyak, V.; Wolf, A.; Dubavik, A.; Borchardt, L.; Voitekhovich, S. V.; Gaponik, N.; Kaskel, S.; Eychmüller, A., 3D Assembly of Semiconductor and Metal Nanocrystals: Hybrid CdTe/Au Structures with Controlled Content. J. Am. Chem. Soc. 2011, 133 (34), 13413-13420. |
|