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Polymer-based ternary nanocomposites with tunable optical properties are the key components for optoelectronics applications. Here, we demonstrate the linear and nonlinear optical properties of polypyrrole (PPy) and its ternary composites with different concentrations of the MoS2–ZnO core–shell (ZnO@MoS2) heterostructure. The interesting observation of multiple excitons and their transportation through the interface of PPy and ZnO@MoS2 by using photoluminescence and fluorescence lifetime spectroscopy was studied. Furthermore, the third-order nonlinear optical properties of all samples were also measured by employing the z-scan technique at an excitation wavelength of 532 nm. The reverse saturable absorption of pure PPy was switched to saturable absorption after the addition of ZnO@MoS2 at the uniform linear transmittance. These ternary composites with good nonlinear responses provide an option for the development of high-performance nonlinear optical devices and open a new path for the future development of ternary systems in the optical fields. [ABSTRACT FROM AUTHOR]

High density, skin effect, and environmental instability are significant limitations that restrict the application of metal-based microwave absorbers in achieving lightweight, high performance, and long service life. This study broke from traditional methods for preparing a microwave absorber Mn 2 O 3 -Fe 3 O 4 @PPy (polypyrrole) by employing an innovative annealing process to convert metal into metal oxide by the introduction of metal organic framework (MOF), which effectively achieving a more lightweight absorber material with hollow porous nanocube structure. Subsequently, PPy was coated onto the metal oxide surface to form a core-shell structure by a situ chemical oxidation synthesis method. The combination of metal oxide of the hollow porous nanocube structure and the core-shell structure formed by highly conductive PPy shell significantly enhanced heterogeneous interfaces and electromagnetic (EM) wave reflection. Excellent dielectric loss and impedance matching contributed evidently to the ultra-wideband EM wave absorption performance. It was demonstrated that, with a filling amount of only 20 wt%, the prepared Mn 2 O 3 -Fe 3 O 4 @PPy achieved an effective bandwidth (EAB) of 10.0 GHz at a thickness of 3.08 mm, with EAB max reaching 13 GHz. At a filling amount of only 10 wt%, the reflection loss (RL) was −62.13 dB, achieving an EAB of 7.4 GHz at 2.98 mm thickness, with EAB max reaching 11.4 GHz. Furthermore, the proposed strategy incorporating metal oxide and PPy enhanced corrosion resistance with higher charge transfer resistance. The ultra-wideband microwave absorption material uses an innovative annealing process for MOF, and then ingenious combines with the coated PPy to form a hollow porous nanocube core-shell structure. Excellent microwave absorption performance: EAB max = 13 GHz, RL min = −62.13 dB, low fill of 10 wt%. In addition, the corrosion resistance of the metal is improved. [Display omitted] [ABSTRACT FROM AUTHOR]

This work describes the synthesis, characterization, and photocatalytic evaluation of a polypyrrole-reinforced zinc-nickel mixed metal ferrite (PPy@ Zn 0.5 Ni 0.5 Fe 2 O 4) nanohybrid. A facile hydrothermal process is employed to synthesize the nanostructured zinc-nickel mixed metal ferrite (ZNF), and in situ oxidative polymerization is utilized to create the PPy nanohybrid. In this nanohybrid, PPy plays multiple roles: preventing charge recombination, reducing photocorrosion, mitigating particle aggregation in ZNF, and enhancing charge transfer and visible light absorption. The combined electron-capturing ability, intrinsic conductivity, and extensive π-conjugation of PPy, along with the magnetic nature of ZNF, render the PPy@ZNF catalyst highly efficient. The results of photoluminescence, impedance, and UV/Vis analysis confirm that PPy plays a critical role in enhancing photocatalytic performance by facilitating charge transfer and extending visible-light absorption. In practical environmental applications, the PPy@ZNF nanohybrid demonstrated superior photocatalytic activity compared to ZNF alone, degrading 98.5 % of malachite green dye under W-lamp light within 80 min, with a rate constant of 0.031 min−1. Scavenger and cyclic experiments identified the active species involved in dye degradation and assessed the reusability of the nanohybrid. Extensive testing revealed the optimal conditions for photocatalytic efficiency; the considered variables included light intensity, catalyst dose, dye concentration, temperature, irradiation time, and pH. These findings suggest that the PPy-reinforced ZNF nanohybrid offers cost-effectiveness, magnetic recoverability, structural stability, and high efficacy as a visible light-driven catalyst, making it a promising candidate for diverse environmental remediation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) has practical applications in healthcare, food security, and environmental protection. The current study has been focused on creating H2O2 sensors using a bimetallic composition of polypyrrole/Cobalt-silver on indium tin oxide (ITO) through electrochemical fabrication. Composite hybrid materials comprising Co@Ag/PPy/ITO were successfully synthesized using chronoamperometry and pulsed electrodeposition techniques. The obtained electrode (Co@Ag/PPy/ITO) was studied using scanning electron microscopy (SEM), ultraviolet–visible, and cyclic voltammetry techniques. The energy-dispersive X-ray spectroscopy and SEM revealed that silver and cobalt nanoparticles were distributed on the PPy surface, forming fern-like structures. A detailed investigation of the electrochemical properties of the bimetallic composition was conducted using cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy. The amperometric method and CV were used to carry out the electrochemical detection of H2O2. The non-enzymatic H2O2 sensor exhibited an enhanced amperometry response, showing a higher sensitivity of 3.664 mA mM−1 cm−2 within a linear range spanning 0.12–2.36 mM. Notably, the sensor achieved a low detection limit of 1.985 μM (S/N = 3). Additionally, the nanocomposite hybrids demonstrated superior stability, repeatability, and reproducibility, making this sensor suitable for long-term use. [ABSTRACT FROM AUTHOR]

Interest in metal electrodeposition for synthesizing customized nanomaterials has resurged, particularly for applications such as sensors and fuel cells. The present study involved the synthesis of ZnSe nanoparticles (via hydrothermal method) while polypyrrole and novel composite Ppy@ZnSePpy@Ppy (via sequential electrodeposition technique) on a glassy carbon (GC) electrode and their physiochemical, electrochemical, and operando spectro-electrochemical characterizations towards oxygen evolution reaction (OER). Results indicated that ZnSe nanoparticles are well embedded within the Ppy layers and during OER the composite electrocatalyst approached 398 mV at 10 mA cm−2 and exhibited Tafel value (b ∼ 75 mV dec−1) with ECSA (0.03) which shows better results than other two. In addition, the operando spectro-electrochemical spectra of the composite revealed the significant generation of active intermediate oxygen species of selenium and Zn2+. The important feature of the current work is the disclosure of Se's questionable role and species involved in OER found to be Se4+. [Display omitted] • State of art Ppy@ZnSePpy@Ppy composite & its physicochemical characterization has been reported. • Electrodeposition method used for synthesis of composite. • First time operando spectroelectrochemical study was carried out to study OER of Ppy@ZnSePpy@Ppy. • The ambiguous role of Se has been revealed. • As Synthesized composite has shown better candidature towards OER. [ABSTRACT FROM AUTHOR]

A thiosemicarbazone‐based iron(III) complex is prepared and used in the preparation of a supercapacitor electrode material. This electrode is produced by a solvothermal reaction of polypyrrole and the complex on carbon felt. The characterization of the complex and material is carried out using UV‐vis, elemental analysis, FT‐IR, XRD, BET, and TGA methods, and the surface morphology is examined using SEM technique. Because the interaction of electrode and electrolyte is of great importance in energy storage systems, as the surface area and pore volume increase, electrode ions at the electrode/electrolyte interface leak to the inner surfaces and interact with the larger surface area, which increases the charge storage performance. The electrode material, nano‐worm structure, reached the highest specific capacitance value of 764.6 F g−1 at 5 mV s−1. Compared to the capacitance value of polypyrrole in its pure form, it is observed to exhibit an 187.2% increase. The highest specific capacitance value of the asymmetric supercapacitor (ASC) formed with a graphite electrode is 318.1 F g−1 at the current density of 1 Ag−1. Moreover, ASC reached a wide working potential of 1.8 V in an aqueous electrolyte and exhibited ultra‐long cycle life (112%), maintaining its stability after 10 000 cycles. [ABSTRACT FROM AUTHOR]

The prospective of percutaneous drug delivery (PDD) mechanisms to address the limitations of oral and injectable treatment for rheumatoid arthritis (RA) is increasing. These limitations encompass inadequate compliance among patients and acute gastrointestinal side effects. However, the skin's intrinsic layer can frequently hinder the percutaneous dispersion of RA medications, thus mitigating the efficiency of drug delivery. To circumvent this constraint, we developed a strontium ranelate (SrR)-loaded alginate (ALG) phototherapeutic hydrogel to assess its effectiveness in combating RA. Our studies revealed that this SrR-loaded ALG hydrogel incorporating photoelectrically responsive molybdenum disulfide nanoflowers (MoS2 NFs) and photothermally responsive polypyrrole nanoparticles (Ppy NPs) to form ALG@SrR-MoS2 NFs-Ppy NPs demonstrated substantial mechanical strength, potentially enabling delivery of hydrophilic therapeutic agents into the skin and significantly impeding the progression of RA. Comprehensive biochemical, histological, behavioral, and radiographic analyses in an animal model of zymosan-induced RA demonstrated that the application of these phototherapeutic ALG@SrR-MoS2 NFs-Ppy NPs effectively reduced inflammation, increased the presence of heat shock proteins, regulatory cluster of differentiation M2 macrophages, and alleviated joint degeneration associated with RA. As demonstrated by our findings, treating RA and possibly other autoimmune disorders with this phototherapeutic hydrogel system offers a distinctive, highly compliant, and therapeutically efficient method. [ABSTRACT FROM AUTHOR]

Highlights In this novel work, we fabricated the multiwalled carbon nanotubes (MWCNTs)/polypyrrole (PPy) nanocomposite by employing the novel ultrasonic dual mixing (UDM) method. Subsequently, the atomistics and structural characterizations of the fabricated MWCNT/PPy nanocomposite (PM) were performed using SEM, Raman, and XRD. Furthermore, we experimentally evaluated the mechanical properties of the fabricated PM by reinforcing the PPy matrix with MWCNTs at different wt.%. The experimental study of PM shows that the mechanical properties depend upon the amount and dispersion quality of MWCNTs in the PPy matrix. In order to validate the experimental outcomes, the conservative fully coupled finite element (FE) models were developed using the ANSYS Workbench and novel FEAST software. The electromagnetic interference (EMI) shielding effectiveness (SE) of developed PM was also calculated at different thicknesses of PM by taking the effect of SE due to absorption (SEA) and SE reflection (SER) in the microwave frequency range of the C‐band (5.37–8.2 GHz) into consideration. The total SE (SET), the cumulative sum of SEA and SER, is the strong function of the thickness of the PM. Additionally, our study's outcomes reveal that as the thickness of the PM increased, the SET also increased by dominating the SEA rather than the SER. The SET value of 75 dB was observed for a sample with a thickness of 3 mm, indicating a high level of shielding. Thus, material becomes a highly attractive option for achieving high‐performance EMI SE in the C‐band for satellite communications, Wi‐Fi devices, weather radar systems, surveillance, and cordless telephones. A complex permittivity and permeability were also studied using the Nicolson–Ross–Weir (NRW) method to understand the mechanism behind the EMI SE. Nanocomposite fabricated using the novel ultrasonic dual mixing method. FE models were developed to validate experimental results. The EC and EMI SE are improved with the increase in the sample thickness. Absorption, rather than reflection, dominated the shielding mechanism. SE was observed ~75$$ \sim 75 $$ dB with good mechanical properties. [ABSTRACT FROM AUTHOR]

The polypyrrole wrapped‐carbon nanotube composites with the core‐shell design are prepared via two‐step self‐assembly originated from the multi‐interactions of dopant, zeolitic imidazolate framework, carbon nanotube and pyrrole. The core composed of carbon nanotube effectively improves the conductivity of the composite and provides stable double‐layer capacitance. The shell composed of polypyrrole and tightly wrapped on carbon nanotubes effectively prevents the volume expansion of polypyrrole while undergoing the process of doping/de‐doping as well as endows supercapacitors with high pseudocapacitance. The polypyrrole‐coated carbon nanotube displays a remarkable specific capacitance of 510 F g−1 when operating at a current density of 1 A g−1. Surprisingly, the assembled polypyrrole wrapped‐carbon nanotube//activated carbon asymmetric supercapacitor not only possesses a high capacitance preservation of 88.5% after 10,000 charge/discharge cycles at 5 A g−1, but also shows superior flexibility and stable electrochemical behaviors when subjected to various bending angles. Furthermore, the flexible polypyrrole wrapped‐carbon nanotube//activated carbon supercapacitor achieves the superb energy density of 86.3 Wh kg−1 and the power density of 800 W kg−1 when operating at 1 A g−1. These results highlight the significant potential of this new generation of flexible supercapacitor devices. Highlights: Polypyrrole is wrapped on carbon nanotube to form a core‐shell structureCNTs improve the conductivity and provides double‐layer capacitanceThe core‐shell design prevents the volume expansion of polypyrroleThe assembled asymmetric supercapacitor shows superior flexibility [ABSTRACT FROM AUTHOR]

A nanocomposite with a unique satellite dish-like structure, termed arsenic (III) oxide iodide (AsO2I)/polypyrrole (Ppy) intercalated with iodide ions (AsO2I/Ppy-I), has been meticulously developed via a two-step process. It features natural satellite dish-like nanostructures, potentially serving as nanoresonators for efficient single photon absorption. With a bandgap of 2.8 eV, the AsO2I/Ppy-I nanocomposite efficiently absorbs photons in the UV and visible light regions, making it suitable for single photon detection. Impressive performance is seen in photocurrent sensitivity measurements, recording values of 0.017 mA.cm−2 under white light and 0.009 mA.cm−2 under monochromatic light at 340 nm. Additionally, it exhibits high responsivity and detectivity, with peak values at wavelengths of 340 nm and 440 nm associated with the diameter of the Satellite dish nanostructure. Cost-effectiveness and simple synthesis methods make it attractive for industrial applications, while its unique structural characteristics and enhanced optical properties position it as a valuable asset in optoelectronic technologies. It holds promise as a leading material in advanced quantum technology, marking a significant leap forward in optoelectronic technologies, with potential applications in quantum cryptography, communication, and computing. [ABSTRACT FROM AUTHOR]

This review article focuses on the potential of cobalt oxide composites with conducting polymers, particularly polypyrrole (PPy) and polyaniline (PANI), as advanced electrode materials for supercapacitors, batteries, and supercapatteries. Cobalt oxide, known for its high theoretical capacitance, is limited by poor conductivity and structural degradation during cycling. However, the integration of PPy and PANI has been proven to enhance the electrochemical performance through improved conductivity, increased pseudocapacitive effects, and enhanced structural integrity. This synergistic combination facilitates efficient charge transport and ion diffusion, resulting in improved cycling stability and energy storage capacity. Despite significant progress in synthesis techniques and composite design, challenges such as maintaining structural stability during prolonged cycling and scalability for mass production remain. This review highlights the synthesis methods, latest advancements, and electrochemical performance in cobalt oxide/PPy and cobalt oxide/PANI composites, emphasizing their potential to contribute to the development of next-generation energy storage devices. Further exploration into their application, especially in battery systems, is necessary to fully harness their capabilities and meet the increasing demands of energy storage technologies. [ABSTRACT FROM AUTHOR]

The nature of rigidity and low energy density of polypyrrole (PPy)‐based electrodes limits their wide application in flexible energy storage devices. In this study, reduced graphene oxide (rGO) wrapped polypyrrole (PPy)/oxidized carbon cloth (OCC) (rGO@PPy/OCC) is prepared by the polymerization of pyrrole using MnO2 as the oxidant on the surface of OCC followed by the adsorption and reduction of graphene oxide (GO). The prepared rGO@PPy/OCC electrode exhibits a high gravimetric specific capacitance of 547 F g−1 at a current density of 0.5 A g−1 and a high area specific capacitance of 1641 mF cm−2 at a current density of 1.5 mA cm−2. It nearly maintains the initial capacitance after 8000 cycles at a high scan rate of 200 mV s−1 and at a large current density of 10 A g−1. Moreover, the flexible rGO@PPy/OCC electrodes are used to construct flexible solid‐state supercapacitors (FSSC). The FSSC based on rGO@PPy/OCC exhibits a high energy density (33.89 Wh kg−1 and 101.81 µWh cm−2) and a capacitance retention of 95.10% after 1000 bending cycles, demonstrating the excellent cycling stability and flexibility. Therefore, it is potential for rGO@PPy/OCC as a flexible electrode to fabricate high‐performance FSSC. [ABSTRACT FROM AUTHOR]

Developing high‐performance platinum (Pt) single atom catalyst with maximum metal‐atom‐utilization efficiency is of significance for water electrolysis, which demonstrates enormous potentials toward hydrogen evolution reaction (HER). In addition to stably immobilizing Pt single atoms on a support material, it is highly desired to elaborately tailor their coordination environments for achieving optimized HER performance. In this work, a general strategy is reported to develop advanced catalysts with Pt single atoms immobilized on conjugated polymers, where their coordination environments and HER activities can be readily tailored by adjusting the cation‐π interactions formed between the Pt single atoms and conjugated polymers. For the proof‐of‐concept study, polypyrrole (PPy), polyfuran (PFu), and polythiophene (PTh) with analogous molecular structures are investigated, where the N, O, and S heteroatoms in PPy, PFu, and PTh can affect their π domains and induce different cation‐π interactions. Experimental and theoretical studies both suggest that the HER performance of the resulting catalysts follows the trend of Pt1‐PTh < Pt1‐PFu < Pt1‐PPy, which shows a correlation with their cation‐π interactions. Moreover, by utilizing the microstructure‐tailorable property of conjugated polymers, PPy aerogel with enhanced specific surface area are prepared to support Pt single atoms, achieving substantial HER performance improvement. [ABSTRACT FROM AUTHOR]

Here we report the operation of p-p heterojunction for improving the H 2 gas sensing performance of ZnMn 2 O 4 /Polypyrrole nanocomposite (PZ) at room temperature. ZnMn 2 O 4 (ZM) with a unique cubic morphology and porous architecture was synthesized via a one-step hydrothermal method. Polypyrrole (PPy) fibers and PZs were prepared through chemical oxidative polymerization of pyrrole monomers in the absence and presence of different weight percentages (wt%) of ZM, respectively. Our findings show that the PZs consisted of microcubic ZMs with dimensions of approximately 8 μm, covered with wire-like PPy fibers. The partial protonated PPy and different wt% of microcubic ZM have a significant effect on H 2 gas sensing. The response of our hand-made sensor increased with increasing wt% of ZM and gas level. The PZ samples exhibited the highest response of 1.23 (the lowest t res value of 21.6 s) at a concentration of 15000 (2500) ppm H 2 gas. Furthermore, the PZ sample contains 10 wt% of ZM demonstrated excellent long-term stability in response after six months, which indicates the accuracy and reliability of the sensor. H 2 gas mechanism of the PZ sensor was studied in details. The advantage of p-p heterojunction could provide a new perspective for H 2 gas sensing applications. [Display omitted] • A H 2 gas sensor developed using p-p heterojunction of ZM microcubes and 1D PPy. • PZ nanocomposites outperformed ZM and PPy in H 2 gas sensing. • PZ sensing layers showed fast t res / t rec , stable performance, and high selectivity. • An in-depth study was conducted on the H 2 gas sensing mechanism of PZ layers. [ABSTRACT FROM AUTHOR]

A new sensor was fabricated for the determination of ketamine (Ket) in urine samples based on enhanced electrochemiluminescence (EECL) behavior of luminol on a carbon paste electrode (CPE) modified with the conductive molecularly imprinted polymer (CMIP) film. The FESEM technique was applied to demonstrate the rod shape morphology of CMIP. Unlike the common luminol system, EECL signal of luminol no need to addition of hydrogen peroxide and it might find application in efforts to avoid instability of hydrogen peroxide or its interference with the analytes of interest. The EECL emission has been optimized by an investigation of the applied potentials, electrochemical polymerization conditions, template and modifier concentrations, and the pH solution. Under the optimum conditions, the EECL signal depended linearly on the Ket concentration within a range from 0.1 to 1.25 μM with a limit of detection (LOD) of 0.08 μM. The sensor exhibited very good recovery percentages ranging from 92% to 101% in urine samples, while precisions were ≤3%. These results suggested that the proposed sensor would be applicable for analysis Ket in complex matrixes without interfering of other drugs (anesthetics) and thus has the potential to be used in clinical application. [ABSTRACT FROM AUTHOR]

Iron microparticles were coated with polypyrrole in situ during the chemical oxidation of pyrrole with ammonium peroxydisulfate in aqueous medium. A series of hybrid organic/inorganic core–shell materials were prepared with 30–76 wt% iron content. Polypyrrole coating was revealed by scanning electron microscopy, and its molecular structure and completeness were proved by FTIR and Raman spectroscopies. The composites of polypyrrole/carbonyl iron were obtained as powders and characterized with respect to their electrical properties. Their resistivity was monitored by the four-point van der Pauw method under 0.01–10 MPa pressure. In an apparent paradox, the resistivity of composites increased from the units Ω cm for neat polypyrrole to thousands Ω cm for the highest iron content despite the high conductivity of iron. This means that composite conductivity is controlled by the electrical properties of the polypyrrole matrix. The change of sample size during the compression was also recorded and provides a parameter reflecting the mechanical properties of composites. In addition to conductivity, the composites displayed magnetic properties afforded by the presence of iron. The study also illustrates the feasibility of the polypyrrole coating on macroscopic objects, demonstrated by an iron nail, and offers potential application in the corrosion protection of iron. The differences in the morphology of micro- and macroscopic polypyrrole objects are described. [ABSTRACT FROM AUTHOR]

In recent years, fatty acids have garnered significant attention as a natural phase‐change material and a hydrophobizer due to their biocompatibility and biodegradability. In this study, the utilization of fatty acid is proposed as a polymerization medium for the first time. As a specific reaction, chemical oxidative polymerizations of pyrrole is conducted using ferric chloride as an oxidant in a stearic acid medium. The polymerizations resulted in the production of micrometer‐sized polypyrrole (PPy) grains, which are aggregates of atypical primary particles with submicrometer size. The PPy grains are doped with stearic acid, suggesting that the stearic acid functioned as a dopant and a hydrophobizing agent as well as a polymerization medium. The dried PPy grains can adsorb at the air–water interface and function as a liquid marble stabilizer with light‐to‐heat photothermal properties. The liquid marble can move on a planar air‐water interface by Marangoni flow induced by NIR laser light irradiation. [ABSTRACT FROM AUTHOR]

Rational heterostructure design can bring interfacial polarization relaxation to significantly enhance the electromagnetic wave (EMW) absorption performance. However, intelligently building a homogeneous heterostructure with superior EMW absorption properties remains a great challenge. Herein, a typical conductive metal–organic framework Cu3(HHTP)2 (hexahydroxytriphenylene, HHTP) is delicately packed onto a polypyrrole (PPy) conductive polymer surface via a one‐step in situ polymerization approach. Results show that Cu3(HHTP)2 is well packed on the PPy surface to form an elegant Cu3(HHTP)2@PPy hybrids interfacial microstructure with a unique superiority regarding EMW absorption compared with single components of PPy and Cu3(HHTP)2. Interestingly, the interfacial microstructure of Cu3(HHTP)2@PPy hybrids can be tuned by adjusting the composition of the PPy and Cu3(HHTP)2, resulting in the improvement of impedance matching, conductive loss, and enhancement of interfacial polarization relaxation, endowing the optimization of the EM wave absorption properties of the Cu3(HHTP)2@PPy. The broad effective absorption bandwidth covers a range as broad as 6.68 GHz (11.00–17.68 GHz), which is higher than most reported metal‐organic frameworks (MOFs) and conductive polymer‐based EM absorbing materials. Herein, new insight for developing highly efficient EMW absorption materials through hybridized interfacial microstructure engineering is provided. [ABSTRACT FROM AUTHOR]

With the rising demand for electricity storage devices, the performance requirements for such equipment have become increasingly stringent. Lithium-sulfur (Li-S) batteries are poised to be among the next generation of energy storage systems. However, before they can be commercially viable, several challenges must be addressed, including low sulfur conductivity and the shuttle effect. Herein, polypyrrole based sulfur composite was prepared by simple method in hydrothermal teflon lined autoclave for Li-S battery. The S/SP/ppy/PVDF electrode exhibited the initial discharge capacity of 662 mAh g− 1 at 0.5 C and 637 mAh g− 1 after 100 cycles. The Coulombic efficiency was 96% all along charge/discharge cycling. Moreover, Li-S coin cells were assembled and tested to demonstrate the potential application and scale-up of the polypyrrole-sulfur composite. [ABSTRACT FROM AUTHOR]

With the escalating prevalence of electromagnetic radiation pollution, flexible electromagnetic interference (EMI) shielding materials hold immense potential for widespread application. Carbonized fabric possesses notable advantages such as flexibility, excellent electrical conductivity, and chemical stability. However, its traditional preparation process is characterized by high energy consumption, intricate atmospheric conditions, and prolonged duration. This study introduces a novel approach of incorporating intumescent flame retardant (IFR) into cotton fabric, aiming to facilitate rapid carbonization in an air atmosphere. Remarkably, this innovative approach yields an outstanding total EMI shielding effectiveness (SET) of 17.55 dB within a mere 5 min carbonization process at 900 °C under ambient air conditions. Moreover, in order to enhance the shielding effect, we conducted in-situ growth of polypyrrole (PPy) on the prepared carbonized fabric. The deposition time of 120 min resulted in an impressive SET value of 28.22 dB, effectively providing a shielding capability of up to 99.9% against electromagnetic waves (EMW). Moreover, the SET value of IFR-C-PPy-60 min can be enhanced to 51.84 dB by stacking 4 layers, enabling the attenuation of 99.999% of EMW. The IFR-C-PPy also demonstrated exceptional fire safety and thermal stability. This study presents a novel approach for the rapid and large-scale fabrication of highly efficient conductive carbonized fabric, which demonstrates potential applications in flexible electronic devices. [ABSTRACT FROM AUTHOR]

Constructing heterostructure is a promising strategy to enhance photocatalytic performance. Here, a cyano and carbon dots/polypyrrole (CDs/PPy) co‐modified carbon nitride (CPKCN) heterostructure is constructed for photocatalytic H2O2 generation. It is interestingly found that the intermediates formed during the oxidation polymerization of pyrrole can be the potential electron trapping sites and reactive sites. In addition, the localized photoheat produced by CDs/PPy also plays an active role in improving photocatalytic activity. Moreover, the addition of CDs/PPy leads to a higher negative zeta potential of CPKCN, which is favorable for the attraction of the sample surface to H+. These features, plus the positive effect of cyano groups, collectively boost the charge transfer and improve the selectivity of two‐electron O2 reduction. Therefore, the enhanced photocatalytic H2O2 generation performance of the developed CPKCN is achieved, with an H2O2 generation rate of 3.7 mmol g−1 h−1 under visible light in a 10 vol% isopropanol (IPA) aqueous solution, and with the apparent quantum yield of 16.7% at 420 nm and the solar‐to‐chemical conversion efficiency of 0.34%. The work offers new insights into developing efficient photocatalysts for various applications. [ABSTRACT FROM AUTHOR]

Enhancing the supercapacitors' performance relies on the increased capacitance and voltage window, which are the current key challenges for developing new materials. In this study, the mononuclear NiII‐bis(oxamato) complex ([nBu4N]2[Ni(opba)], 1) has been synthesized and used as a template in polypyrrole (PPy) based conductive polymer as a novel electrode material for supercapacitor applications. The surface and structural properties of PPy and PPy/1 electrodes were studied using SEM and TEM to elucidate their interactions. The results of characterization techniques revealed that complex 1 altered the morphology, creating a prominent three‐dimensional globular structure in the PPy/1 hybrid material without significant chemical modification. The electrochemical properties of PPy and PPy/1 were investigated by CV, EIS, and GCD analyses. The PPy/1 electrode demonstrated intense pseudocapacitive behavior, showing a significantly widened potential window and increased current compared to the PPy electrode, resulting in enhanced energy storage capacity within the material. This improvement was evaluated by testing a symmetric supercapacitor in a coin cell architecture with an alginate‐based gel acting as both electrolyte and separator. The maximum specific cell capacitance reached 41.6 F g−1 at a current density of 0.2 A g−1, with a remarkable capacity retention of 97 % after 1000 galvanostatic charge/discharge cycles. [ABSTRACT FROM AUTHOR]

A hierarchical reduced graphene oxide-MnO2@polypyrrole coaxial nanotube composite hydrogel was prepared via oxidative polymerization of pyrrole in the presence of MnO2 nanotubes, followed by the hydrothermal treatment of graphene oxide and MnO2@polypyrrole coaxial nanotubes. The stable composite hydrogel with a hierarchical network was composed of one-dimensional MnO2@polypyrrole coaxial nanotube and two-dimensional graphene nanosheet and characterized by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface, and X-ray photoelectron spectroscopy measurements. The composite hydrogel can be used as an efficient adsorbent for Cr(VI) removal due to the synergistic interaction between graphene and MnO2@polypyrrole and the hierarchical structure of the hydrogel. Moreover, the composite hydrogel is easily separated because of its stable monolith, and it is reusable (76.8% of removal ability remaining after five adsorption-desorption cycles). The simple fabrication and cost-effective separation process together with the excellent absorption performance endow the composite hydrogel with great potential for practical wastewater treatment. [ABSTRACT FROM AUTHOR]

Supercapacitors have drawn a lot of interest as energy storage devices because of their high-power density, quick charge/discharge rates, and long cycle life. However, the creation of cutting-edge electrode materials is essential in order to further improve their performance. Nanostructures made of graphene-based conducting polymers have shown promise because they combine the special qualities of both graphene and conducting polymers. In the present research, we synthesized the composites of reduced graphene oxide and polypyrrole conducting polymer by in situ chemical polymerization by varying their mass ratio. The fabricated samples were characterized by FTIR spectroscopy, Raman spectroscopy, TEM, XPS, XRD, and cyclic voltammetry for further analyses for these nanostructures' potential application in energy storage devices. Composite fabrication was verified through FTIR and Raman spectroscopy by confirming distinct peaks. TEM studies confirmed the presence of thin and randomly aggregated graphene oxide nanoparticles. XPS survey spectra identified carbon, nitrogen, and oxygen, with major peaks at 284 eV, 399 eV, and 531 eV, reflecting variations in C, N, and O. Cyclic voltammetry determined specific capacitance values of 4.66 F/g and 6.11 F/g for different mass ratios of polypyrrole and reduced graphene oxide. [ABSTRACT FROM AUTHOR]

A novel platform has been developed for the sensitive label-free detection of mutation in the TP53 gene, one of the most prominent genes in cancer research. The platform is based on the electrochemical properties of functionalized multi-walled carbon nanotubes (f-MWCNTs), gold nanoparticles (AuNPs), and polypyrrole (PPy). The microscopic structure and morphology of the prepared films on an ITO electrode surface were characterized using X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared (FTIR). The hybridization events specific to the TP53 gene were monitored using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrode, which incorporates vertically aligned f-MWCNTs arrays and AuNPs, exhibited enhanced probe DNA attachment density, improving the sensitivity of the DNA sensor. The combination of AuNPs/PPy with an in-situ produced f-MWCNTs array provides a viable strategy for developing a highly sensitive biosensor for fast mutation detection in human cancer types. [ABSTRACT FROM AUTHOR]

This review delves into various Conducting Polymer (CP)-based supercapacitors, including polyaniline, polypyrrole, polyindole, polythiophene, and their derivatives. It covers fabrication methods, design concepts, and the types of electrolytes used along with their recent advancements and ongoing challenges. It explores the future direction of flexible supercapacitor materials and their potential impact on flexible electronic applications. The review focuses on the relationship between conductivity, polymer structure, and electrochemical performance, fabrication strategies, including advanced deposition techniques and solution-based methods. Initiatives to enhance electrochemical performance, such as integrating nanostructured materials, selecting electrolytes, and engineering interfaces have also been discussed. Mechanical challenges under bending and stretching conditions are also addressed. It offers a vital analysis of materials, fabrication methods, and performance enhancement in conducting polymer-based flexible supercapacitors, serving as a valuable resource for those involved in flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Pure organic films consisting of polypyrrole, polyaniline and a composite of polypyrrole and polyaniline electrodeposited in the ionic liquid EMIM‐TFSI onto mesoporous carbon electrodes are tested for their hydrogen evolution reaction capabilities. The use of these intrinsically conducting polymers is seen as a way of stepping away from expensive and rare metallic catalysts. Co‐polymerisation of polypyrrole and polyaniline in a 1 : 10 ratio in EMIM‐TFSI was found to be doped with the TFSI− anion and be much more active to the hydrogen evolution reaction when compared to pure polymers. Tafel analysis of the composite gave a value of 144 mV/dec indicating that the Volmer step is the rate limiting step. However, stability tests showed an improvement in the composite's overpoential performance for the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

A novel solar steam generator featuring divergent microchannels (SSG‐DM) is developed via directional freezing of a polypyrrole (PPy)–cellulose nanofiber (CNF) suspension in an inverted frustum mold. Contrary to the conventional 3D SSGs characterized by random micropores (SSG‐RM), SSGs incorporating vertical microchannels (SSG‐VM), fabricated through directional freezing procedure, demonstrate increased evaporation performance due to enhanced water transport to the top surface. However, SSG‐VM manifests a limitation in the form of reduced salt resistance on its side surfaces where water transport is restricted. This issue is addressed by directional freezing of a PPy–CNF suspension in an inverted frustum mold, followed by freeze‐thawing gelation in an AlCl3 solution. The fabricated SSG features divergent microchannels that spanned from the bottom surface to the top and side surfaces, with a gradual increase in diameter. The evaporation rate of SSG‐DM is recorded at 2.42 kg m−2h−1 under 1‐sun illumination; this rate further increases to 15.73 kg m−2h−1 in the presence of a 4 m s−1 wind. Notably, SSG‐DM demonstrates excellent salt resistance in highly saline brine (10 wt%) under windy conditions (4 m s−1), whereas SSG‐RM and SSG‐VM are ineffective under the same conditions. [ABSTRACT FROM AUTHOR]

NiCo 2 S 4 with a spherical spinel structure was innovatively synthesized from discarded mobile phone batteries using a simple hydrothermal method, and the surface was coated with N-doped carbon to form NiCo 2 S 4 @NC. The products were used as anode materials of sodium-ion batteries to study the effect of the N-doped carbon layer on the electrochemical properties, structure and morphology. The results of XRD, FESEM and TEM revealed that the N-doped carbon layer derived by carbonizing polypyrrole had a minimal effect on the structure and morphology of NiCo 2 S 4 , but was coated on the surface of NiCo 2 S 4 with different thicknesses to adjust the electrochemical performance. The presence of N-doped carbon in NiCo 2 S 4 @NC was confirmed by Raman spectroscopy. The mesoporous structure of NiCo 2 S 4 and NiCo 2 S 4 @NC was corroborated by N 2 adsorption-desorption isotherm analysis, and the optimal specific surface area and pore size were 23.14 cm2/g and 18.0 nm, respectively. X-ray photoelectron spectroscopy indicated that Co2+/Co3+ and Ni2+/Ni3+ coexist in the spinel NiCo 2 S 4 @NC 50 synthesized upon adding 50 μL of pyrrole monomer. NiCo 2 S 4 @NC 50 outperformed other products in terms of its electrochemical properties, where its initial discharge specific capacity under the current density of 0.1 A g−1 was 1099.6 mA h g−1 and the specific capacity following 100 cycles reached 327.5 mA h g−1. NiCo 2 S 4 @NC 50 exhibited an optimal electrochemical performance and demonstrated a competent approach toward recycling discarded mobile phone batteries and building electrodes with high performance for use in energy equipment. [ABSTRACT FROM AUTHOR]

Recent interest in tissue engineering (TE) has focused on electrically conductive biomaterials. This has been inspired by the characteristics of the cells' microenvironment where signalling is supported by electrical stimulation. Numerous studies have demonstrated the positive influence of electrical stimulation on cell excitation to proliferate, differentiate, and deposit extracellular matrix. Even without external electrical stimulation, research shows that electrically active scaffolds can improve tissue regeneration capacity. Tissues like bone, muscle, and neural contain electrically excitable cells that respond to electrical cues provided by implanted biomaterials. To introduce an electrical pathway, TE scaffolds can incorporate conductive polymers, metallic nanoparticles, and ceramic nanostructures. However, these materials often do not meet implantation criteria, such as maintaining mechanical durability and degradation characteristics, making them unsuitable as scaffold matrices. Instead, depositing conductive layers on TE scaffolds has shown promise as an efficient alternative to creating electrically conductive structures. A stratified scaffold with an electroactive surface synergistically excites the cells through active top-pathway, with/without electrical stimulation, providing an ideal matrix for cell growth, proliferation, and tissue deposition. Additionally, these conductive coatings can be enriched with bioactive or pharmaceutical components to enhance the scaffold's biomedical performance. This review covers recent developments in electrically active biomedical coatings for TE. The physicochemical and biological properties of conductive coating materials, including polymers (polypyrrole, polyaniline and PEDOT:PSS), metallic nanoparticles (gold, silver) and inorganic (ceramic) particles (carbon nanotubes, graphene-based materials and Mxenes) are examined. Each section explores the conductive coatings' deposition techniques, deposition parameters, conductivity ranges, deposit morphology, cell responses, and toxicity levels in detail. Furthermore, the applications of these conductive layers, primarily in bone, muscle, and neural TE are considered, and findings from in vitro and in vivo investigations are presented. Tissue engineering (TE) scaffolds are crucial for human tissue replacement and acceleration of healing. Neural, muscle, bone, and skin tissues have electrically excitable cells, and their regeneration can be enhanced by electrically conductive scaffolds. However, standalone conductive materials often fall short for TE applications. An effective approach involves coating scaffolds with a conductive layer, finely tuning surface properties while leveraging the scaffold's innate biological and physical support. Further enhancement is achieved by modifying the conductive layer with pharmaceutical components. This review explores the under-reviewed topic of conductive coatings in tissue engineering, introducing conductive biomaterial coatings and analyzing their biological interactions. It provides insights into enhancing scaffold functionality for tissue regeneration, bridging a critical gap in current literature. [Display omitted] [ABSTRACT FROM AUTHOR]

Here, the use of cellulose films (CFs) produced from low‐quality cotton is reported as a template for in situ synthesis of well‐known conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPY) via oxidative polymerization. Three successive monomer loading/polymerization cycles of aniline (ANI) and pyrrole (PY) within CFs as PANI@CF or PPY@CF are carried out to increase the amount of conductive polymer content. The contact angle (CA) for three times ANI and PPY loaded and polymerized CFs as 3PANI@CF and 3PPY@CF are determined as 26.3±2.8 and 42.3±0.6 degrees, respectively. As the electrical conductivity is increased with increased number of conductive polymer synthesis within CF, the higher conductivity values, 3×10−4±8.1×10−5 S.cm−1 and 2.1×10−3±5.8×10−4 S.cm−1, respectively are measured for 3PANI@CF and 3PPY@CF composites. It is found that PANI@CF composites are hemolytic, whereas PPY@CF composites are not at 1 mg mL−1 concentrations. All PPY@CF composites exhibit better biocompatibility than PANI@CF composites on L929 fibroblast cells with more than 70±8% viability at 1 mg of CF‐based conductive polymer composites. Moreover, MIC and MBC values of 3PPY@CF composites for Escherichia coli (ATCC8739) and Staphylococcus aureus (ATCC6538) are determined as 2.5 and 5.0 mg.mL−1, whereas these values are estimated as 5 and 10 mg.mL−1 for Candida albicans (ATCC10231). [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of a Ni-doped coral-like three-dimensional Mo 2 C nanorod via the pyrolysis of polypyrrole (PPy)-loaded NiMoO 4 ·xH 2 O nanorods for nitrobenzene (NB) detection. The incorporation of Ni species into Mo 2 C enhances dual-atom synergistic catalysis, while the inclusion of PPy as a preferred carbon source improves the composite's active area. The coral-like three-dimensional rod structure not only provides various types of sites for adsorbing reactants but also offers more channels for ion migration and electron transfer, promoting charge transfer and further enhancing its electrical conductivity. The resulting composite demonstrates a wide linear detection range (2.11–1053.61 μM), high sensitivity, low limit of detection (0.64 μM, S/N = 3), and excellent stability and anti-interference performance in NB detection. This novel composite preparation approach offers promising prospects for practical NB detection applications. [ABSTRACT FROM AUTHOR]

Flexible devices, such as soft bioelectronics and stretchable supercapacitors, have their practical performance limited by electrodes which are desired to have high conductivity and capacitance, outstanding mechanical flexibility and strength, great electrochemical stability, and good biocompatibility. Here, we report a simple and efficient method to synthesize a nanostructured conductive hydrogel to meet such criteria. Specifically, templated by a hyperconnective nanofibrous network from aramid hydrogels, the conducting polymer, polypyrrole, assembles conformally onto nanofibers through in-situ polymerization, generating continuous nanostructured conductive pathways. The resulting conductive hydrogel shows superior conductivity (72 S cm−1) and fracture strength (27.2 MPa). Supercapacitor electrodes utilizing this hydrogel exhibit high specific capacitance (240 F g−1) and cyclic stability. Furthermore, bioelectrodes of patterned hydrogels provide favorable bioelectronic interfaces, allowing high-quality electrophysiological recording and stimulation in physiological environments. These high-performance electrodes are readily scalable to applications of energy and power systems, healthcare and medical technologies, smart textiles, and so forth. [ABSTRACT FROM AUTHOR]

Amyloid‐β (Aβ) pathway is positioned as the center for Alzheimer's disease (AD) pathophysiology. Viable drugs targeting Aβ pathway are developed with promising outcomes. Meanwhile, most current approaches are focused on the inhibition of Aβ fibrillization or elimination of Aβ plaques by immunotherapeutic strategies. Here, near‐infrared (NIR) photothermal polypyrrole nanoparticles coated with peptide‐polyphenol are developed to both inhibit the Aβ fibrillization and disaggregate Aβ fibrils synergistically. Aβ fibrillization is obviously inhibited after being treated with the photothermal polypyrrole nanoparticles. Besides inhibition of Aβ fibrillization, the amount of Aβ fibrils is gradually reduced with time by 38.0% when co‐incubated with polypyrrole nanoparticles, indicating desired disaggregation capability against Aβ fibrils. In addition, faster and more disaggregation of Aβ fibrils is observed when irradiation by NIR light. Meanwhile, cellular studies also verified that this nanoparticle is able to effectively reduce the cytotoxicity of Aβ fibrils toward PC12 cells through disaggregating toxic Aβ aggregates and maintaining integral membrane structure. Hence, this peptide‐polyphenol‐coated NIR photothermal polypyrrole nanoparticle provides a new perspective for the inhibition of Aβ fibrillization and disaggregation of Aβ fibrils, which can serve as a promising approach for anti‐amyloidosis. [ABSTRACT FROM AUTHOR]

An electrochemical platform for signal amplification probing chloride ions (Cl−) is constructed by the composite integrating core–shell structured nitrogen-doped porous carbon@Ag-based metal–organic frameworks (NC@Ag-MOF) with polypyrrole (PPy). It is based on the signal of solid-state AgCl derived from Ag-MOF, since both NC and PPy have good electrical conductivity and promote the electron transport capacity of solid-state AgCl. NC@Ag-MOF was firstly synthesized with NC as the scaffold and then, PPy was anchored on NC@Ag-MOF by chemical polymerization. The composite NC@Ag-MOF-PPy was utilized to modify the electrode, which exhibited a higher peak current and lower peak potential during Ag oxidation compared with those of Ag-MOF and NC@Ag-MOF-modified electrodes. More importantly, in the coexistence of chloride (Cl−) ions in solution, the NC@Ag-MOF-PPy-modified electrode displayed a fairly stable and sharp peak of solid-state AgCl with the peak potentials gradually approaching zero, which might effectively overcome the background interference caused by electroactive substances. The oxidation peak currents of solid-state AgCl increased linearly with the concentration of Cl− ions in a broad range of 0.15 µM–40 mM and 40–250 mM, with detection limits of 0.10 µM and 40 mM, respectively. The practical applicability for Cl− ions determination was demonstrated using human serum and urine samples. The results suggest that NC@Ag-MOF-PPy composite could be a promising candidate for the construction of the electrochemical sensor. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have been widely used in soft robotics, as well as skin-attached and implantable bioelectronic devices. Among the candidates of conductive fillers, conductive polymers have become popular due to their intrinsic conductivity, high biocompatibility, and mechanical flexibility. However, it is still a challenge to construct conductive polymer-incorporated hydrogels with a good performance using a facile method. Herein, we present a simple method for the one-pot preparation of conductive polymer-incorporated hydrogels involving rapid photocuring of the hydrogel template followed by slow in situ polymerization of pyrrole. Due to the use of a milder oxidant, hydrogen peroxide, for polypyrrole synthesis, the photocuring of the hydrogel template and the growing of polypyrrole proceeded in an orderly manner, making it possible to prepare conductive polymer-incorporated hydrogels in one pot. The preparation process is facile and extensible. Moreover, the obtained hydrogels exhibit a series of properties suitable for biomedical strain sensors, including good conductivity (2.49 mS/cm), high stretchability (>200%), and a low Young's modulus (~30 kPa) that is compatible with human skin. [ABSTRACT FROM AUTHOR]

In this study, Zn-Al ferrite/polypyrrole (PPy) nanocomposites were synthesized and thoroughly characterized to explore their potential for microwave applications. X-ray diffraction analysis confirmed the presence of ZnO, AlFeO3, and Fe2O3 phases, with the crystal size decreasing from 31 nm to 19.6 nm as aluminum content increased. High-resolution transmission electron microscopy (HR-TEM) revealed a distinctive core–shell morphology, where the polypyrrole encapsulates the ZnAlxFe2−xO4 particles. Magnetic measurements showed that decreasing aluminum concentration led to a reduction in both saturation magnetization (Ms) from 75 emu/g to 36 emu/g and remanent magnetization (Mr) from 2.26 emu/g to 2.00 emu/g. Dielectric analysis indicated that both the real (ε′) and imaginary (ε″) components of dielectric permittivity decreased with increasing frequency, particularly between 10 and 14 GHz. Furthermore, electrical modulus analysis highlighted the significant impact of aluminum doping on relaxation time (τIP), indicating the presence of interface polarization. Impedance spectroscopy results underscored the dominance of interface polarization at lower frequencies and the presence of strong conduction paths at higher frequencies. These combined magnetic and dielectric loss mechanisms suggest that the Zn-Al ferrite/polypyrrole nanocomposite is a promising candidate for advanced microwave absorption applications. [ABSTRACT FROM AUTHOR]

This work elucidates the fabrication and electrochemical performance of solid-state symmetric supercapacitors based on polyaniline and polypyrrole films synthesized through electrochemical deposition. The study systematically investigates the impact of electrolyte pH on the performance of these devices, comparing responses in acidic, neutral, and alkaline environments. The polyaniline-based device demonstrates a superior response in acidic electrolyte conditions, which is attributed to the protonation/deprotonation mechanisms inherent in the polymer matrix, a phenomenon that is explored and interpreted in the paper. However, the symmetric supercapacitor employing polypyrrole exhibits superior performance in both acidic and alkaline electrolytes, suggesting the pseudocapacitive nature of polypyrrole even in alkaline conditions. The redox behavior of polypyrrole in alkaline environments primarily relies on the exchange of hydroxide ions, facilitating polypyrrole's superior retention of its redox characteristics compared to polyaniline. The findings contribute to the rational design of solid-state supercapacitors tailored for specific electrolyte conditions, with potential applications in diverse electrochemical energy storage systems. [ABSTRACT FROM AUTHOR]

Traditional polyurethane coating is prepared by combining isocyanate and polyol, but isocyanate is toxic, which is not conducive to the sustainable development of ecological environment. In this paper, dibutyltin dilaurate (DBTDL) was used as catalyst to synthesize dicyclic carbonate from four different acids and glycerol carbonates. Then, it was gradually polymerized with isophorone diamine (IPDA) and 4,4'-diaminodiphenyl disulfide ether to synthesize self-healing non-isocyanate polyurethane (NIPU). The effects of different acid types on coating forming and self-healing properties of NIPU were studied. Then, polypyrrole modified carbon nanotubes were prepared and physically blended with NIPU to obtain a responsive NIPU gel coating. The results show that NIPU has excellent scratch repair performance at 70°C by optical microscopy; Through the dissolution and re-formation of NIPU by N, N-dimethylformamide, it is proved that the material has repeatable processability and is conducive to the sustainable development of ecological environment; The high precision multimeter proved that NIPU has the responsiveness under different chemical environment of acid, alkali, oxidation and reduction. The coating has broad application prospects in biomimetic technology, biology, electronics and other fields. [ABSTRACT FROM AUTHOR]

This work presents the preparation of a gold-polypyrrole (Au-PPy) composite film on a silicon (Si) semiconductor supported by electrodeposition, and the study of its electrocatalytic activity as an anode catalyst for the glucose oxidation reaction in alkaline media. The microstructure of the as-prepared Au-PPy film is characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the presence of the polymer film on the Si support improves the conductivity of the latter and enables better distribution of the Au microparticles on the electrode surface, thus helping to increase their catalytic activity for glucose oxidation. [ABSTRACT FROM AUTHOR]

In‐suit nitrogen‐doped carbon layer coated on CoFe2O4 nanomembrane (NC−CoFe2O4) directly grown on carbon cloth was successfully fabricated. The electrochemical performance was conveniently manipulated by regulating the molar ration of Co2+ : Fe3+ (molar ration=1 : 2, CoFe2O4 nanomembrane, 2.9 F cm−2). Nitrogen‐doped (N‐doped) carbon coating strategy on CoFe2O4 nanomembrane (NC−CoFe2O4) via annealing of polypyrrole (PPy) was presented and NC−CoFe2O4 nanomembranes displayed a prominent capacitance of 12.1 F cm−2 (2563.8 F g−1) at 5 mA cm−2. More important, the composite demonstrated more stable microstructure and showed long‐term cycling stability (16.0 % decrease after 7000 cycles), which was significantly better than the unmodified CoFe2O4 (55.8 % decrease after 1000 cycles). To verify the practicability of the materials, an aqueous asymmetric supercapacitor has been fabricated using NC−CoFe2O4 composite anode and MnO2/CNTs cathode, and the device has a remarkable wide operating voltage range of 1.9 V. In addition, the assembled device has an exceptional specific capacity of 1.3 F cm−2 at 10 mA cm−2, high energy density (43.3 Wh kg−1 at a power density of 642.9 W kg−1), and also with a good capacity retention rate of 84.9 % after 1000 cycles. [ABSTRACT FROM AUTHOR]

This study is inspired by the importance of advanced composites, combining spontaneous magnetization with electrical charge storage properties. It is focused on the investigation of magnetically hard SrFe12O19 (SFO) material and its composites with polypyrrole (PPy). For the first time, an organic surfactant–charge transfer mediator and high-energy ball milling (HEBM) were applied to the preparation of high-active-mass SFO composite electrodes. An important finding was the ability to achieve enhanced capacitance of SFO and its composites in a negative range of electrode potentials in an electrolyte. The benefits of the sodium sulfate electrolyte and the charge storage mechanism are discussed. Another important finding was the synergy of the properties of SFO and PPy, which allowed the preparation of highly capacitive conductive composites. The effects of HEBM and the SFO content in the composites on the capacitive properties were studied. Magnetic measurements revealed the effect of HEBM on the magnetic properties and demonstrated good magnetic properties of the composites, which also exhibited advanced capacitive properties. The composites were utilized for the manufacturing of an asymmetric device, which exhibited high capacitive properties at an applied voltage of 1.5 V. [ABSTRACT FROM AUTHOR]

Chromium(VI) is one of the most toxic metal ions as it can bioaccumulate and its excessive assimilation may result in anaemia, nervous system failure, kidney damage, cancers of the digestive tract and lungs. In this study a polypyrrole (PPy) modified with histidine (His) by in situ polymerisation technique was investigated for the removal of Cr(VI) from aqueous and characterised by means of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), high resolution-transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS).The influence of solution pH, adsorption time, initial adsorption concentration, temperature and coexisting ions on its adsorption were investigated. The results showed that the optimum adsorption pH was 2.0 with the adsorption being endothermic and chemisorption in nature. Mono-layer adsorption was witnessed as the Langmuir isotherm best described the process with a maximum adsorption capacity 274.73 mg g−1 at 25 °C. Although the removal of Cr(VI) was the primary drive, the reduction of Cr(VI) to Cr(III) during treatment turned out to be very significant to avoid secondary pollution. The adsorption mechanisms were mainly ion exchange, electrostatic attractions, complexation, chelation reactions with protonated histidine sites and reduction. Remarkably, the His-PPy nanocomposite exhibited an exceptional removal for Cr(VI) ions after three cycles of adsorption–desorption (over 99%) suggesting the adsorbent's exceptional recyclability. The adsorption equilibrium was attained from 60 to 150 min and best described by pseudo-second-order kinetics. The high adsorption efficiency, stability and selectivity makes the His-PPy nanocomposite adsorbent potentially suitable for large-scale Cr(VI) ions removal from water. [ABSTRACT FROM AUTHOR]

The concern regarding tetrodotoxin (TTX), a highly hazardous marine neurotoxin found in puffer fish, has expanded beyond Asia due to the migration of puffer fish caused by the rise in global temperatures. This highlights the urgent need to develop fast yet reliable methods for detecting TTX. In this study, we developed a peptide-based potentiometric TTX sensor based on a polypyrrole/Au nanoparticle-modified carbon screen-printed electrode (PPy/AuNP SPE). The bioreceptor responsible for recognizing TTX is a specific binding peptide that was discovered through phage display technique. The phage-displayed peptide candidates were sorted based on frequency and similarity, and their binding affinity was subsequently assessed via phage enzyme-linked immunosorbent assay. The C-terminal of the specific binding peptide was then modified with cysteamine to facilitate its immobilization through Au–S bonding on the PPy/AuNP SPE platform, thereby constructing the TTX sensor. The sensing platform was prepared by successive electrodeposition of polypyrrole and AuNP onto the surface of carbon SPE as a substrate. Both materials play significant roles to improve the poor conductivity of carbon SPE and provide sufficient immobilization sites for TTX receptors, respectively. Finally, the PPy/AuNP TTX sensor demonstrated a detection limit of around 2.80 ppb with a detection range from 2 to 1000 ppb, making it a promising platform for rapid and reliable marine toxin detection. [ABSTRACT FROM AUTHOR]

This study presented the electrochemical deposition of potassium nitrate-doped polypyrrole (Ppy:KNO3) on stainless steel (SS), graphite sheet (GRs), and carbon fiber (CF) substrates, Ppy:KNO3/SS, Ppy:KNO3/GRs, and Ppy:KNO3/CF supercapacitor electrodes. Structural, morphological, and molecular analyses were conducted using X-ray diffraction (XRD), scanning electronic microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). SEM images exhibited distinct morphologies of Ppy:KNO3 films, varying with cycles, scan rates, and Ppy:KNO3 concentrations. Ppy:KNO3/CF film displayed a unique structure with minimal particle aggregation. Electrochemical performance was assessed through Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) measurements and electrochemical impedance spectroscopy (EIS). Notably, Ppy:KNO3/CF demonstrated a specific capacitance of 1020 F/g at 1 A/g. It exhibited 92 % capacitance retention after 1000 cycles, along with impressive power and energy densities of 310 W/kg and 71.2 Wh/kg, respectively. These results represented a significant progress in the development of high-performance, durable supercapacitors.

Abstract The prospective of percutaneous drug delivery (PDD) mechanisms to address the limitations of oral and injectable treatment for rheumatoid arthritis (RA) is increasing. These limitations encompass inadequate compliance among patients and acute gastrointestinal side effects. However, the skin’s intrinsic layer can frequently hinder the percutaneous dispersion of RA medications, thus mitigating the efficiency of drug delivery. To circumvent this constraint, we developed a strontium ranelate (SrR)-loaded alginate (ALG) phototherapeutic hydrogel to assess its effectiveness in combating RA. Our studies revealed that this SrR-loaded ALG hydrogel incorporating photoelectrically responsive molybdenum disulfide nanoflowers (MoS2 NFs) and photothermally responsive polypyrrole nanoparticles (Ppy NPs) to form ALG@SrR-MoS2 NFs-Ppy NPs demonstrated substantial mechanical strength, potentially enabling delivery of hydrophilic therapeutic agents into the skin and significantly impeding the progression of RA. Comprehensive biochemical, histological, behavioral, and radiographic analyses in an animal model of zymosan-induced RA demonstrated that the application of these phototherapeutic ALG@SrR-MoS2 NFs-Ppy NPs effectively reduced inflammation, increased the presence of heat shock proteins, regulatory cluster of differentiation M2 macrophages, and alleviated joint degeneration associated with RA. As demonstrated by our findings, treating RA and possibly other autoimmune disorders with this phototherapeutic hydrogel system offers a distinctive, highly compliant, and therapeutically efficient method.

Abstract A nanocomposite with a unique satellite dish-like structure, termed arsenic (III) oxide iodide (AsO2I)/polypyrrole (Ppy) intercalated with iodide ions (AsO2I/Ppy-I), has been meticulously developed via a two-step process. It features natural satellite dish-like nanostructures, potentially serving as nanoresonators for efficient single photon absorption. With a bandgap of 2.8 eV, the AsO2I/Ppy-I nanocomposite efficiently absorbs photons in the UV and visible light regions, making it suitable for single photon detection. Impressive performance is seen in photocurrent sensitivity measurements, recording values of 0.017 mA.cm−2 under white light and 0.009 mA.cm−2 under monochromatic light at 340 nm. Additionally, it exhibits high responsivity and detectivity, with peak values at wavelengths of 340 nm and 440 nm associated with the diameter of the Satellite dish nanostructure. Cost-effectiveness and simple synthesis methods make it attractive for industrial applications, while its unique structural characteristics and enhanced optical properties position it as a valuable asset in optoelectronic technologies. It holds promise as a leading material in advanced quantum technology, marking a significant leap forward in optoelectronic technologies, with potential applications in quantum cryptography, communication, and computing.

Abstract With the rising demand for electricity storage devices, the performance requirements for such equipment have become increasingly stringent. Lithium-sulfur (Li-S) batteries are poised to be among the next generation of energy storage systems. However, before they can be commercially viable, several challenges must be addressed, including low sulfur conductivity and the shuttle effect. Herein, polypyrrole based sulfur composite was prepared by simple method in hydrothermal teflon lined autoclave for Li-S battery. The S/SP/ppy/PVDF electrode exhibited the initial discharge capacity of 662 mAh g− 1 at 0.5 C and 637 mAh g− 1 after 100 cycles. The Coulombic efficiency was 96% all along charge/discharge cycling. Moreover, Li-S coin cells were assembled and tested to demonstrate the potential application and scale-up of the polypyrrole-sulfur composite.

[Display omitted] Portal vein tumor thrombus (PVTT) formed by cancer cell invasion is a major cause of high mortality in hepatocellular carcinoma (HCC), and the formation of thrombus will be accelerated by bacterial colonization on the surface of the implant after surgery. In this work, Polypyrrole-coated arsenic-loaded layered double hydroxide films were in situ constructed on the nickel-titanium alloy for the efficient killing of tumour cells by thermo-therapeutic synergistic chemotherapy. The good near-infrared photothermal conversion ability of polypyrrole enables the sample surface temperature to be raised to about 51 °C at a low photothermal power (0.5 w/cm2), while the elevated temperature could further accelerate the release of drug arsenic. In addition, when NIR light is not applied, the polypyrrole coating also cleverly acts as a "barrier layer" to reduce the natural release of arsenic in normal tissues to avoid toxicity issues. In vivo and in vitro experiments have demonstrated that the platform exhibits excellent antitumor and antibacterial abilities. In contrast to the systemic toxicity issues associated with systemic circulation of nanotherapeutic drugs, this in situ functional film is expected to be used in localised interventions for precise drug delivery, and is also more suitable for surgical treatment scenarios in PVTT surgeries. [ABSTRACT FROM AUTHOR]