Polyaniline with high crystallinity degree: Synthesis, structure, and electrochemical properties

Abstract

Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE-SEM), Fourier transforms infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). FE-SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI-2 < PANI-6 < PANI-10. XPS measurements displayed that PANI polymerized at 6 mA cm 22 (PANI-6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI-6 possessed highest crystallinity degree (X cr ) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI-6 possessed greater discharge capacity and better reversibility.In this study, PANI with high crystallinity degree was synthesized by galvanostatic method on the basis of several points of view: the production is purer and more homogeneous, the devices are facile, and different thickness films could be obtained by controlling polymerization time and/or current density. The data about its spectral properties, structure, conductivity, and electrochemical properties were presented. The effect of polymerization current density on the structure, degree of oxidation (DO), doping level (DL), and crystallinity degree was investigated. The relationship between structure and electric properties was discussed. EXPERIMENTAL ReagentsAniline (C 6 H 7 N, analytical grade from Xi'an Chemical Industry, China) was distilled under reduced pressure before use.

Polyaniline‐Acetylene black‐Copper cobaltite based ternary hybrid material with enhanced electrochemical properties and its use in supercapacitor electrodes

“…Spectroscopic bands at 1563 and 1467 cm -1 signify vibrational stretching of C=C based quinoid and benzenoid ring, respectively. 35,36 C=NH + is present at around 2346 cm -1. 32 The functional groups of acetylene black are found at 1561cm -1 (C-C) and 3450 cm -1 (O-H).…”

An Enzyme‐free H2O2 Sensor Based on Poly(2‐Aminophenylbenzimidazole)/Gold Nanoparticles Coated Pencil Graphite Electrode

“…Also, the peak at 1421 cm À1 is ascribed to the ring vibration of the ortho substituted phenyl group [16]. A band at 1030 cm À1 may indicate the presence of positive charges in polymer chains and 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 also assigned to the CÀN stretching vibrations of the aminophenyl group [16,18]. At the peak at 1245 cm À1 is assigned to inplane CÀH deformation of benzimidazole and phenyl ring [17].…”

Growth Processes and Morphological Evolution of Polyaniline Film During Potentiostatic Growth

“…After 300 s, the resulting PAni-300s shows a much thicker and rougher surface consisting of a compact fibrous structure with voids. 10 The band at~1550 cm −1 is mainly attributed to C N stretching vibrations of quinoid units (N Q N), whereas that at~1450 cm −1 is ascribed to the C C aromatic ring stretching vibration of benzenoid units (N B N). Under these conditions the surface roughness reaches a maximum (Rq = 607 nm) after 300 s, and decreases at later times.…”

“…Among conducting polymers, polyaniline (PAni) has been extensively studied because of its attractive electrical, electrochemical, and optical properties, and its potential applications in fields such as sensors, batteries, electronic devices, and electrochromic displays. Studies of electrochemical growth processes have been performed employing three different methods: potentiostatic (constant potential), 5-7 galvanostatic (constant current), [8][9][10] and potentiodynamic (cyclic voltammetry). 4 One of the most important points in the electrochemical studies of conducting polymers is the understanding of nucleation/growth processes.…”

“…Studies of electrochemical growth processes have been performed employing three different methods: potentiostatic (constant potential), 5-7 galvanostatic (constant current), [8][9][10] and potentiodynamic (cyclic voltammetry). [5][6][7][8][9][10][11][12][13] However, few systematic studies have been conducted on the growth processes and morphological evolution of PAni films during potentiostatic growth. 8,14 There have been several studies conducted on the electrochemical growth processes of PAni.…”