Electrochemical fabrication of nanoporous gold decorated with manganese oxide nanowires from eutectic urea/choline chloride ionic liquid
responsabile: Ing. Claudio Mele
Porous materials are of critical importance in many key technologies, such as catalysis, sensing, and filtration, and thus there is a continuous interest in the discovery of new porous materials, new methods to fabricate them, and new techniques to process them into useful forms. In our research we intend to fabricate and characterize a thin, metallic, nanoporous gold (NPG) film. Crucial to the formation of NPG is the chemical etching process called dealloying, which is the selective dissolution of one or more components from a metallic solid solution.
Our work is based on the idea of: (i) fabricating the Au alloy by electrodeposition, (ii) carrying out Mn dealloying by controlled electrochemical corrosion, (iii) reprecipitating the dealloyed material in the form of a functional oxide decorating the nanoporous gold structure, achieved by dealloying. In particular, we intend to develop a MnO2 nanowires/NPG system for supercapacitors and Li-ion batteries. Our growth process uses an electrodeposition bath based on an eutectic urea/choline chloride ionic liquid followed by an electrochemical oxidation step performed in an aqueous solution.
Cracking of Fe interconnects in ionic liquid-based nano-PEMFC half cells
responsabile: Prof. Benedetto Bozzini
Fabrication of nano fuel-cells is a serious technological challenge for miniaturisation and integration into electronic devices and implementation of on-chip systems. The principal interest of fuel-cell material problems is particularly related to durability issues of critically degradable Proton Exchange Membrane Fuel Cell (PEMFC) components, such as: membranes, catalysts and interconnects. The ideal service-life without major maintenance actions for a PEMFC should amount to several tens of thousands hours, a target performance currently far from achievement. A nanotechnology approach is the key to attain a long-term material performance since an anticorrelation has been conjectured between the spatial scale of controlled defects in a given material and the timescale of the material durability.
In the special case of PEMFCs nanotechnologies can offer improved routes to the fabrication of several components. As far as interconnect materials are concerned, bipolar materials using nanocomposites have been considered in order to achieve higher durability and lower contact resistance between bipolar plates and gas-diffusion layers. The research will be focussed on peculiar mechanico-electrochemical failure modes of the Fe interconnects of open cells implementing a composite Nafion/RTIL electrolyte, Pt black as catalyst, an Au feeder electrode and an Fe test electrode.