Paper MI-ThP3
A Facile and Controllable Two-Step Electrodeposition Technique in Synthesis of Nanostructures of Metal Oxides on Carbon Nanotube S

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

The nano dimensions of materials are comparable to the size of the target analyte biomolecule, higher catalytic reaction, better affinity binding or more efficient molecule-capturing may occur, leading to high sensitivity. And it is possible to use nanoparticle tags for designing electrical bioaffinity assays with remarkable sensitivity and multiplexing ability. So far, efforts have always been made to design novel nanomaterials useful in solving emerging bioanalytical problems such as rapidness, anti-interfering ability, specificity, stability and sensitivity. Synergies of nanocomposite materials, generally retaining the functional properties of each component and possibly yield synergistic effects via cooperative interactions, have exploited a new area to miniaturize and optimize nano-scale sensors and electronics. The synergistic interesting new features include but not limited to increased surface area, enhanced electrocatalytic activities, improved biocompatibility, promoted electron transfer and better invulnerability against intermediate species. A lot of efforts have been made to fabricate nanocomposite materials of metals/metal oxides nanostructures and carbon materials, using a number of techniques, including sputtering, sol–gel, hydrothermal, microwave and electrodeposition from different precursor solutions containing complex agents. Among these, electrodeposition is the easiest, most controllable, environment-friendly and robust technique for synthesis of metal/ metal oxides NPs, in which, the size, density, composition and even the shape of NPs could be well-controlled by electrodeposition potential, time, concentration and composition of metal precursor solutions.

Herein, we report a general two-step approach of electrodeposition useful in facile, controllable and 'green' electrochemical synthesis of metal oxide NPs onto carbon supports, using carbon nanotubes (CNTs) as an example. First, metal nanostructures were electrochemically deposited onto carbon supports at a constant potential with the density, size, shape and elctrocatalytic activities of the produced nanostructures well-controlled by the time and deposition potential applied as well as the concentration of the precursor solution. Then the as-deposited metallic nanostructures were oxidized into metal oxide nanostructures by repetitive potential cycling with extent of oxidation and generation of metal oxides controlled by the number of potential circles.The as-synthesized metal oxides-CNTs composites were characterized and applied as a glucose sensor for illustration of their electrocatalytic properties.