Oxide electrodes microporosity

Oxide materials which are attractive because of their catalytic activity are often employed in the form of finely divided powders of considerable surface area. The history of the material and the preparation technique employed are important aspects to be considered when electrokinetic data are compared. Oxide powders can be hot pressed into sintered pellets, supported, or impregnated, on to carbons of high specific area, and bonded with Teflon or other inert material into composite electrodes. Microporosity of the system may produce an ill-defined surface zone flooded by electrolyte with imprecise ratio of real surface area to geometric cross-section. Sput-... 

However, while the above was a rather crude approach to fabricate more porous electrode layers with oxidic support materials, a more elegant way was chosen for home-made ATO by 3D morphology engineering. ATO powder with unique hollow-sphere morphology was synthesized by ultrasonic spray p)irolysis (USP). Depending on precursor concentration and temperature, this process yields a powder composed of individual nano-crystallites forming the shells of hollow spheres with a controlled nano- and microporosity [98]. This offers efficient mass transport and is assumed to prevent the collapse of the electrode structure with time during operation. 

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