Advanced materials synthesis at the nano and macro scale: An electrochemical approach.

摘要

There are many environmentally demanding and specific applications which require synthesis of advanced materials which are either difficult to make or extremely expensive on a large scale using standard methods such as integrated circuit fabrication. These applications can range from the need to modify the surface properties of an alloy in order to inhibit corrosion processes to reducing the size of a particular metal or semiconductor in order to confine electrons, which occurs as length scale is reduced to between 1–20 nm. There are a multitude of tools, techniques and processing steps that can be utilized to synthesize these materials. Electrochemical techniques offer an inexpensive method that utilizes the large installed manufacturing base to modify the surface of materials and to produce materials with necessary sizes.; A methodology to electrochemically produce advanced materials was followed that (1) identified applications where advanced materials were necessary, (2) identified electrochemical techniques that could produce those materials with appropriate templates providing the necessary control over size and geometry, (3) developed a general framework and/or simple one-dimensional model to understand what factors were necessary to control or manipulate in order to produce an advanced material with the proper material performance and (4) finally, these materials were synthesized and evaluated using electrochemical and surface analysis techniques.; The versatility of this approach was shown through four applications that included (1) elimination or minimization of the environmentally hazardous Cr(III)/Cr(VI) redox couple from conversion coating formulations, (2) electrophoretic synthesis of ordered nano-arrays from colloidal materials for use as sensors, (3) synthesis of two- and three-dimensional electrodes for fuel cell applications, and (4) development of a process to produce semiconductor wires for improvements in photovoltaic devices and infrared detectors.