Electrosynthesis of poly(aniline-co-azure B) for aqueous rechargeable zinc-conducting polymer batteries

Tackling the Challenges of Aqueous Zn-Ion Batteries via Polymer-Derived Strategies

Zn-ion batteries (ZIBs) have gathered unprecedented interest recently benefiting from their intrinsic safety, affordability, and environmental benignity. Nevertheless, their practical implementation is hampered by low rate performance, inferior Zn2+ diffusion kinetics, and undesired parasitic reactions. Innovative solutions are put forth to address these issues by optimizing the electrodes, separators, electrolytes, and interfaces. Remarkably, polymers with inherent properties of low-density, high processability, structural flexibility, and superior stability show great promising in tackling the challenges. Herein, the recent progress in the synthesis and customization of functional polymers in aqueous ZIBs is outlined. The recent implementations of polymers into each component are summarized, with a focus on the inherent mechanisms underlying their unique functions. The challenges of incorporating polymers into practical ZIBs are also discussed and possible solutions to circumvent them are proposed. It is hoped that such a deep analysis could accelerate the design of polymer-derived approaches to boost the performance of ZIBs and other aqueous battery systems as they share similarities in many aspects.

Electropolymerization of a Carbonyl-Modified Dihydropyrazine Derivative for Aqueous Zinc Batteries with Ultrahigh Cycling Stability

The design of aqueous zinc-ion batteries (ZIBs) that have high specific capacity and long-term stability is essential for future large-scale energy storage systems. Cathode materials with extended π-conjugation and abundant active sites are desirable to enhance the charge storage performance and the cycling stability of the aqueous ZIB. Based on this concept, 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetrone was chosen as the monomer to be electropolymerized onto carbon cloth (PDHPQ-Tetrone/CC). When used as the cathode material for aqueous ZIBs, an exceptional cycling life (>20,000 cycles) at a current density of 10 A g-1 was achieved, with the specific capacity maintained at 82.8% and with the Coulombic efficiency at around 100% throughout cycling. At the charge-discharge current density of 0.1 A g-1, the ZIB with PDHPQ-Tetrone/CC achieved a high specific capacity of 248 mAh g-1. Kinetic analyses showed that both surface-capacitive-controlled processes and semi-infinite diffusion-controlled processes contribute to the stored charge. The charge storage mechanism was investigated with ex situ characterizations and involves the redox processes of carbonyl/hydroxyl and amino/imino groups coupled with insertion and extraction of both Zn2+ and H+.

Dynamic Study of Intercalation/Deintercalation of Ionic Liquids in Multilayer Graphene Using an Alternating Current Raman Spectroscopy Technique

We report Raman spectra and infrared (IR) imaging collected during the intercalation-deintercalation half cycles in a multilayer graphene (MLG) device (∼100 layers) operating at 0.2-10 Hz. The device consists of a MLG/alumina membrane/copper stack, in which the alumina membrane is filled with ionic liquid [DEME][TFSI], forming an electrochemical cell. Upon the application of a positive voltage, the TFSI- anions intercalate into the interstitial spaces in the MLG. The incident laser light is modulated using an optical chopper wheel that is synchronized with (and delayed with respect to) a 0.2-10 Hz alternating current (AC) voltage signal. Raman spectra taken just 200 ms apart show the emergence and disappearance of the intercalated G band mode at around 1610 cm-1. By integration of over hundreds of cycles, a significant Raman signal can be obtained. The intercalation/deintercalation is also monitored with thermal imaging via voltage-induced changes in the carrier density, complex dielectric function ε(ω), and thermal emissivity of the device.

Synthesis and characterization of PANI and PANI-indole copolymer and study of their antimalarial and antituberculosis activity

The preparation of polyaniline (PANI) and its copolymer with indole involved a chemical oxidative polymerization method, with benzene sulfonic acid (BSA, C6H6O3S) used as a dopant and potassium persulfate (PPS, K2S2O8) as an oxidant. The synthesized compounds underwent characterization using FTIR, 1H-NMR, TGA, and GPC techniques, which allowed the calculation of their average molecular weight and polydispersity index (PDI) through the GPC technique. The PDI values of the PANI copolymer with indole in different aniline-to-indole ratios were 1.53, 1.13, and 1.532 for 1:1, 1:2, and 2:1 ratios, respectively. Thermal stability was determined using TGA, revealing that the indole heterocyclic compound increased the inflexibility of the polymer chains in the synthesized PANI copolymer. The structure of the copolymer was further analyzed using 1HNMR and FTIR techniques, which confirmed the existence of benzenoid and quinoid groups in the PANI-indole copolymers, as well as the effect of doping on the polymer chains. The antibacterial and antifungal properties of the copolymers were studied against several bacterial and fungal strains and measured in terms of minimum inhibitory concentration. Results indicated that the inhibition rate of the PANI-indole copolymer on S. pyogenus (MTCC 442) was higher than that of standard drugs and individual PANI. The PANI-indole copolymers also displayed excellent antituberculosis and antimalarial activities, with the synthesized copolymer showing better outcomes than individual PANI.

Life cycle thinking and safe-and-sustainable-by-design approaches for the battery innovation landscape

Developments in battery technology are essential for the energy transition and need to follow the framework for safe-and-sustainable-by-design (SSbD) materials, chemicals, products, and processes as set by the EU. SSbD is a broad approach that ensures that chemicals/advanced materials/products/services are produced and used in a way to avoid harm to humans and the environment. Technical and policy-related literature was surveyed for battery technologies and recommendations were provided for a broad SSbD approach that remains firmly grounded in Life Cycle Thinking principles. The approach integrates functional performance and sustainability (safety, social, environmental, and economic) aspects throughout the life cycle of materials, products, and processes, and evaluates how their interactions reflect on SSbD parameters. 22 different types of batteries were analyzed in a life cycle thinking approach for criticality, toxicity/safety, environmental and social impact, circularity, functionality, and cost to ensure battery innovation has a green and sustainable purpose to avoid unintended consequences.

Electrochemical DNA Sensor Based on the Copolymer of Proflavine and Azure B for Doxorubicin Determination

A DNA sensor has been developed for the determination of doxorubicin by consecutive electropolymerization of an equimolar mixture of Azure B and proflavine and adsorption of native DNA from salmon sperm on a polymer film. Electrochemical investigation showed a difference in the behavior of individual drugs polymerized and their mixture. The use of the copolymer offered some advantages, i.e., a higher roughness of the surface, a wider range of the pH sensitivity of the response, a denser and more robust film, etc. The formation of the polymer film and its redox properties were studied using scanning electron microscopy and electrochemical impedance spectroscopy. For the doxorubicin determination, its solution was mixed with DNA and applied on the polymer surface. After that, charge transfer resistance was assessed in the presence of [Fe(CN)₆]^3-/4- as the redox probe. Its value regularly grew with the doxorubicin concentration in the range from 0.03 to 10 nM (limit of detection 0.01 nM). The DNA sensor was tested on the doxorubicin preparations and spiked samples mimicking blood serum. The recovery was found to be 98-106%. The DNA sensor developed can find application for the determination of drug residues in blood and for the pharmacokinetics studies.

Organic Cathode Materials for Rechargeable Zinc Batteries: Mechanisms, Challenges, and Perspectives

Energy and environmental issues have given rise to the development of advanced energy-storage devices worldwide. Electrochemical energy technologies, such as rechargeable batteries, are considered to be the most reliable and efficient candidates. Compared with other batteries, zinc-based batteries seem promising due to their advantages, including inherent safety, cost-effectiveness, and environmentally friendliness. As potential alternatives to conventional inorganic cathodes, organic cathodes for Zn-organic batteries have become a hot topic for research, owing to their favorable characteristics, such as easy structure design, controllable synthesis, and environmental benignancy. Herein, a systematic overview on the fundamentals of organic cathode materials for zinc batteries, including material design, electrochemical mechanisms, technical advances, and challenging analysis, is provided. Furthermore, perspectives and corresponding research directions are offered to facilitate the future development of organic cathode materials for zinc batteries toward practical applications.

Tyrosinase based amperometric biosensor for determination of tyramine in fermented food and beverages with gold nanoparticle doped poly(8-anilino-1-naphthalene sulphonic acid) modified electrode

The aim of the present work was to develop an amperometric biosensor for tyramine (Tyr) measurement in food and beverages. The biosensor architecture is based on tyrosinase (Tyr_ase) immobilization on glassy carbon electrode modified by a nanocomposite consisting of gold nanoparticles (AuNP) synthesized by a green method and poly(8-anilino-1-naphthalene sulphonic acid) modified glassy carbon electrode. Under optimized experimental conditions for fixed potential amperometric detection, the biosensor exhibited a linear response to tyramine in the range 10-120 µM and the limit of detection was estimated to be 0.71 µM. The novel platform showed good selectivity, long-term stability, and reproducibility. The strong interaction between tyrosinase and the nanocomposite was revealed by the high value of the Michaelis-Menten constant (79.3 μM). The fabricated biosensor was successfully applied to the determination of Tyr in dairy products and fermented drinks with good recoveries, which makes it a promising biosensor for quantification of tyramine.

High-performance rechargeable aqueous Zn-ion batteries with a poly(benzoquinonyl sulfide) cathode

Aqueous Zn-ion batteries with a poly(benzoquinonyl sulfide) cathode show good electrochemical performance.