Fabrication Of Multi-Functional Nanocomposites By Layer-by-Layer Technichque And Related Property Study

With the development of material science, synthesizing multi-functional nanocomposite materials by simple methods have been the hot research spot of material chemistry, for that single functional nanomatrials cannot satisfy the demand of practical applications yet. Assembly of single functional materials to multi-functional nanocomposite materials not only retains functions of each component, but also endows the nanocomposites fantastic properties that cannot be acquired in single functional components. The novel properties originated from the synergic effect between each component may compensate the drawback of single functional materials and create a new filed of material design.The layer-by-layer technology provides a convenient and effective way to construct nanocomposite materials. It can easily assemble species with opposite charges to composite bilayers, making the combination of various functional species possible. With the micromation of electronic devices, self-assembled multilayer films containing multifunctional nanocomposites will play more and more important roles in the fabrication of electronic devices. Depositing metal on semiconductor is of significant interest to obtain their synergic properties due to the electronic characteristics of semiconductor and metal. Herein, we constructed semiconductor/metal ions-containing multilayer at first, and then heating treatment was carried out to reduce metal ions forming ZnO/Au nanocomposites in the films. The combined experimental results suggest that the ZnO/Au nanocomposite-loaded films are not only sensitive to electron transfer kinetics but also have good conductivity. Furthermore, we expand the LbL technology from synthesizing planar nanocomposites to unplanar one-dimensional nanocomposites. Positively charged polyelectrolyte PDDA was selected as glue to assemble negatively charged Keggin and Dawson type polyoxometalates and carbon nanotubes (CNTs). Experimental results demonstrated that the basic structures of polyoxometalates are still preserved in the nanocomposites. Electrochemical study verified that functionalization of CNTs with polyoxometalates not only retains the unique properties of nanotubes, but also endows CNTs the reversible redox activity of polyoxometalates. The obtained nanocomposites may have important potential uses in electrocatalysis and charge storage in redox capacitors. Hence, The controllable combination of various kinds of functional materials may pave a way for the development of material science and the exploitation of new materials.