ULTRATHIN SUPPORTED GRAPHITE OXIDE AND CARBON-FILMS

A wet colloid-chemical synthetic method is considered as a new approac h to supported nanostructured graphite oxide (GO) and carbon films. Th e films are prepared by self-assembly from aqueous colloids of chemica lly exfoliated GO onto substrates of different nature: Al2O3; MgO; ZnO ; Si; GdSi (42% Si) powders fumed silica and a Si plate containing sur face nanostructured Si layer. The procedure works on both planar and h igh surface area substrates. It was found by X-ray diffraction and X-r ay photon spectroscopy analysis that the chemical nature of substrate surface, in particular its basicity, determines the structure and part icles orientation of the GO layer whose thickness increases with an in crease of GO concentration in the starting suspension. Thermal treatme nt of the GO films leads to GO decomposition and the formation of supp orted carbon films. The GO deposition has been shown to increase 8-30 times the adsorption capacity of the substrates toward Cu(II) amino co mplexes. The GO film adsorption capacity can be controlled by varying GO concentration of the starting suspension. The maximum GO adsorption capacity (24 mmol g(-1)) is observed for the samples which were prepa red using the suspensions with GO concentration of 0.3-0.4 gl (-1), an d is close to the total quantity of oxygen-containing groups in GO. (C ) 1998 Published by Elsevier Science Ltd. All rights reserved.