Controllable Synthesis And Application Of Conducting Polymer And Their Hybrid Functional Films With Electroactive Performances

This field encompasses mixed (electron-ion) conducting materials whose bulk phases can be charged/discharged electronically from an external electric circuit or by chemical agents. To retain the electroneutrality of the phase the transferred electronic charge must be compensated by the incorporation/expulsion of ionic species. Such a phenomenon is characteristic of numerous systems with very diverse chemical natures, including redox or electronically conducting polymers, inorganic solids with mixed-valence transition metals, and lithium cation intercalation layers, placed in contact with an electrolyte solution. Despite the broad variety of underlying molecular mechanisms, the electrochemical processes occurring in these materials possess many common features. It is important that the EM with high electronic transfer rate, high ion exchange capacity and high stability, was found and synthesized.In this paper, the all cis-polyaniline nanotube film was successfully obtained using a novel unipolar pulse electro-polymerization method. To the best our knowledge, this is the first report and confirmation of this kind promising film composed of all cis-polyaniline nanotubes. To date, although various polyaniline-based materials have been synthesized and used in different fields, little attention has been paid to these potentially important species on which the chemical and physical properties of polyaniline are based. Only a few scattered reports can be found in the literatures with respect to the molecular conformation of PANI and the effects of possible isomeric forms on the intrinsic properties of polyaniline. That may be why some conflicting results were reported even by some highly respectable research groups. Therefore, in order to understand the performance mechanism of PANI and to determine the intrinsic properties of PANI, it should be very interesting if we can synthesize PANI preferably in one isomeric form or as a mixture containing a smaller than usual number of different isomer. In the present study, we found a facile way to get the all cis-polyaniline nanotube film and its formation mechanism was also analyzed and discussed. Furthermore, many excellent performances such as less charge transfer resistance, better water wettability, higher apparent diffusion coefficient, higher redox site capacity and super-stability of all cis-polyaniline nanotube film with the unique chemical molecular conformation were identified and successfully applied for the supercapacitor and high sensitive ascorbic acid sensor. It is expected that this advanced material will be applied in many electrochemical fields based on this Study.In this paper, the PPDC film was successfully obtained using a novel unipolar pulse electro-polymerization method and its electronic switch copper ion exchange mechanism was analyzed and discussed. The process and mechanism of copper ion exchange were characterized by electrochemical quartz crystal microbalance (EQCM), X-ray Photoelectron Spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The PPDC film prepared had good stability and high ion exchange capacity, and should be useful in practical heavy metal ion waste treatment.Unipolar pulse waveforms consist of an applied anode potential during the on-period and an open-circuit potential during the off-period. Unipolar pulse electrodeposition was used to fabricate nickel hexacyanoferrate/chitosan/carbon nanotubes (NiHCF/CS/CNTs) nanocomposite films with controllable structure on electrode surface and the as-prepared films were applied in hydrogen peroxide (H2O2) sensor. One-step electrodeposition of NiHCF/CS/CNTs film with insoluble-structure NiHCF nanoparticles was performed, and the whole procedure took only several minutes. The morphology and the composition of the NiHCF/CS/CNTs film were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS). With the introduction of CNTs, the formed NiHCF/CS/CNTs system showed synergy between CNTs and NiHCF with a significant improvement of redox activity of NiHCF due to the excellent electron-transfer ability of CNTs. Electrochemical experiments revealed that the modified electrode allowed low potential (-0.2V) detection of H2O2and showed high electrocatalytic activity to the reduction of H2O2. The linear range for the detection of H2O2was0.04-5.6mM with a high sensitivity of654mA M-1cm2, and the response was very fast (less than2s). A detection limit of as low as2.8×10-7M (S/N=3) for H2O2was achieved.Electroactive hybrid films with cubic nickel hexacyanoferrate/polyaniline (NiHCF/PANI) were synthesized on carbon nanotubes (CNTs) modified platinum electrodes by a facile one-step electrosynthesis method using cyclic voltammetry (CV). The morphologies and structures of the as-prepared NiHCF/PANI/CNTs films were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Due to the introduction of CNTs with carboxyl groups, an acidic micro-environment was provided for the nitrogen atoms in the PANI chains, which could maintain its electroactivity in neutral aqueous solutions. The hybrid films were applied for hydrogen peroxide (H2O2) detection and showed synergy and higher electrocatalytic activity with a higher sensitivity, a faster response time and a lower detection limit. It was found that detection sensitivity could be regulated by controlling the time of CV of electrosynthesis during the preparation of the hybrid film. A catalytic rate constant of1.29×108cm3·mol-1·s-1was obtained from an investigation of the kinetics of the catalytic reaction. SEM images showed that the cubic composite nano-particles of PANI and NiHCF were formed and distributed uniformly on the CNTs. The hybrid film prepared had good stability and reproducibility in the detection of H2O2, and should be useful in practical H2O2sensors.