Abstract
A variety of layered transition metal oxides with cation-exchange properties were delaminated into their unilamellar nanosheets by reacting their protonated form with bulky organic cations. Exfoliation of anion-exchangeable hosts of layered double hydroxides was attained by the action of formamide upon their NO3-or ClO4- form. Ionexchange reactivity played an important role in these delamination processes. The resulting two-dimensional nanosheets can be used as a building block to fabricate a range of nanostructured materials. Addition of appropriate electrolytes into a colloidal suspension of nanosheets induced flocculation to yield a restacked structure. Sequential adsorption of nanosheets with polyelectrolytes could produce layer-by-layer assembled multilayer films having precisely controlled nanostructures. These processes could be applied to design a range of functional materials, e.g. fluorescent materials, photocatalysts, dielectrics, electrochromic films.
