Assembly of ligand-stripped nanocrystals into precisely controlled mesoporous architectures

Nano Lett. 2012 Jul 11;12(7):3872-7. doi: 10.1021/nl302206s. Epub 2012 Jun 22.

Abstract

The properties of mesoporous materials hinge on control of their composition, pore dimensions, wall thickness, and the size and shape of the crystallite building units. We create ordered mesoporous materials in which all of these parameters are independently controlled. Different sizes (from 4.5 to 8 nm) and shapes (spheres and rods) of ligand-stripped nanocrystals are assembled using the same structure-directing block copolymers, which contain a tethering domain designed to adsorb to their naked surfaces. Material compositions range from metal oxides (Sn-doped In(2)O(3) or ITO, CeO(2), TiO(2)) to metal fluorides (Yb,Er-doped NaYF(4)) and metals (FePt). The incorporation of new types of nanocrystals into mesoporous architectures can lead to enhanced performance. For example, TiO(2) nanorod-based materials withstand >1000 electrochemical cycles without significant degradation.