Carbon Supported Polyaniline as Anode Catalyst: Pathway to Platinum-Free Fuel Cells

The effectiveness of carbon supported polyaniline as anode catalyst in a fuel cell (FC) with direct formic acid electrooxidation is experimentally demonstrated. A prototype FC with such a platinum-free composite anode exhibited a maximum room-temperature specific power of about 5 mW/cm2Comment: 11 pages, 3 Postscript figures, atricle tex styl

Use of facile mechanochemical method to functionalize carbon nanofibers with nanostructured polyaniline and their electrochemical capacitance

A facile approach to functionalize carbon nanofibers [CNFs] with nanostructured polyaniline was developed via in situ mechanochemical polymerization of polyaniline in the presence of chemically treated CNFs. The nanostructured polyaniline grafting on the CNF was mainly in a form of branched nanofibers as well as rough nanolayers. The good dispersibility and processability of the hybrid nanocomposite could be attributed to its overall nanostructure which enhanced its accessibility to the electrolyte. The mechanochemical oxidation polymerization was believed to be related to the strong Lewis acid characteristic of FeCl3 and the Lewis base characteristic of aniline. The growth mechanism of the hierarchical structured nanofibers was also discussed. After functionalization with the nanostructured polyaniline, the hybrid polyaniline/CNF composite showed an enhanced specific capacitance, which might be related to its hierarchical nanostructure and the interaction between the aromatic polyaniline molecules and the CNFs

Preparation and Application of Electrodes in Capacitive Deionization (CDI): a State-of-Art Review

As a promising desalination technology, capacitive deionization (CDI) have shown practicality and cost-effectiveness in brackish water treatment. Developing more efficient electrode materials is the key to improving salt removal performance. This work reviewed current progress on electrode fabrication in application of CDI. Fundamental principal (e.g. EDL theory and adsorption isotherms) and process factors (e.g. pore distribution, potential, salt type and concentration) of CDI performance were presented first. It was then followed by in-depth discussion and comparison on properties and fabrication technique of different electrodes, including carbon aerogel, activated carbon, carbon nanotubes, graphene and ordered mesoporous carbon. Finally, polyaniline as conductive polymer and its potential application as CDI electrode-enhancing materials were also discussed

The First Products of Aniline Oxidation – SERS Spectroelectrochemistry

There are different opinions on the first products of aniline oxidation throughout the scientific community. While electrochemists basically accept only linear oligomers with repeating units joint in para positions, chemists have proposed formation of various branched and polycyclic oligomers. It was also suggested that one of these structures, N-phenyl-phenazinium cation, is responsible for the adherence of polyaniline films to substrates. In this work, a surface enhanced Raman spectroscopic and spectroelectrochemical analysis of the species adsorbed onto gold surface in aniline-containing solution at pH 1 and 5 is presented. The influence of the pH value on the oligomer structure is declared. The results are discussed in the context of linear and branched/phenazine-like aniline oligomers. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Electromagnetic shielding of polypyrrole-sawdust composites: polypyrrole globules and nanotubes

Economic and efficient materials for the shielding of electromagnetic interference are required by many applications. Electrically conducting composite materials based on wood sawdust modified by polypyrrole (PPy) with different morphology, globular and nanotubular, were prepared through in-situ polymerization of pyrrole with the use of iron (III) chloride as an oxidant. The effect of PPy morphology and content in composite with sawdust on the DC conductivity and shielding effectiveness (SE) were investigated. Composites of sawdust with globular PPy demonstrated higher DC conductivity as compared to those with PPy nanotubes as long as PPy content was less or equal to 18 vol.%. Above this concentration the opposite trend was observed. The SE of composites was evaluated theoretically in the radio-frequency range, and measured by waveguide method in the frequency range 5.85–8.2 GHz. The SE increased with increase in DC conductivity, and good agreement between the theoretically calculated SE and experimental results was achieved. The SE of the composites extended over 20 dB level above 18 vol.% PPy at the thickness of the order of 10 μm. Polypyrrole nanotubes perfomed better than globular PPy at high conducting polymer content. The composites are good candidates for the application as shielding materials in the microwave band. © 2017, Springer Science+Business Media B.V.Ministry of Education, Youth and Sports of the Czech Republic (NPU I) [LO1504]; Czech Science Foundation [16-02787S