Recovery of Electrochemical Properties of Polyaniline-Based Multilayer Films with Improved Electrochemical Stability

Abstract

Owing to its unique structure and reduction–oxidation (redox) properties, polyaniline (PANI) has been widely used in diverse applications, including sensors, solar cells, electrochromic devices, batteries, and supercapacitors. However, irreversible redox reactions between different oxidation states of PANI often result in low chemical and electrochemical stability, deteriorating devices’ performance characteristics. Herein, we fabricated PANI-based multilayer films using spin-assisted layer-by-layer assembly, providing significantly improved chemical and electrochemical stability compared to the PANI homopolymer. More importantly, we found that the electroactivity and electrical conductivity of PANI-based films can be restored by a simple chemical reactivation process using an acidic aqueous solution. The re-doping process successfully recovers the electrochemical properties of PANI, even improving the electroactivity and conductivity characteristics of polyacid-doped PANI films, attributed to the secondary doping and rearrangement of polymers. Furthermore, we demonstrate that the performance of PANI multilayer films for ammonia sensors is successfully restored after the reactivation process.

Melamine-Based Nanocomposites for Selective Dopamine and Uric Acid Sensing

“…through electrochemical polymerization can improve the overall performance of the sensor. 29 Herein, using melamine as a carbon source and boric acid as a dopant, nitrogen-/boron-doped CDs are prepared by hydrothermal prepolymerization. A PMEL-CDs/MWCNTs-COOH nanocomposite was prepared by electropolymerization of a nanomonomer (CDs fixed melamine residues) on a modified electrode in chloride ion solution for selective detection of DA and UA.…”

“…Further regulation of the electrical activity and conductivity of the polymer (such as number of scan cycles, scan rate, etc.) through electrochemical polymerization can improve the overall performance of the sensor …”

Thermally Cross-Linked Copolymer for Highly Transparent to Multicolor-Showing Electrochromic Materials

“…Electrochromic materials can undergo stable and reversible changes in optical properties under external voltage. , Recently, electrochromic materials have been widely studied in the fields of smart windows, automotive anti-glare rearview mirrors, electronic tags, displays, and other advanced wearable technologies, and some of them have already been applied. − Polymer-based electrochromic materials (PEC) have received more and more attention owing to their easy structural modification, wide color changes, high optical contrast, and fast switching time. − However, for application in transmissive electrochromic devices (like smart windows or smart glasses), higher requirements have been proposed in terms of high transparency, large optical contrast, and excellent cycling stability. − …”

Sulfonate-Functionalized Two-Dimensional Metal–Organic Framework as a “Dispersant” for Polyaniline to Boost Its Electrochemical Capacitive Performance

“…Developing techniques to store electrical energy generated from the sources of renewable energy has become significantly crucial in recent years. , Among various energy-storage methods, electrical energy storage (EES) has attracted great attention and has been widely utilized in electric vehicles and various portable electronic devices. , Owing to their moderately high energy density and power density, supercapacitors are the attractive options of EES that can fill in the gaps between the batteries and conventional capacitors. , Thus, various active materials for supercapacitors, including porous carbons, transition-metal oxides, , and conducting polymers, , have been developed in order to achieve outstanding capacitive performances. Among these materials, polyaniline (PANI), a common conducting polymer, is particularly of interest owing to its high electrical conductivity, processability, and considerable theoretical specific capacitance. ,, The charging and discharging processes of PANI rely on its fast and reversible electrochemical reactions along with the adsorption and desorption of ions. ,, It is thus expected that PANI with a large exposed surface area to render more redox-active sites electrochemically addressable should be highly desirable for use in supercapacitors to achieve a high capacitance close to the theoretical value.…”