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In this contribution we describe the formation of gold nanoparticles (AuNP)and polyaniline (PANI) AuNP-PANI nanocomposite via in situ enzymaticpolymerization. The method consists of electrostatic adsorption of aniliniummonomers on AuNPs citrate stabilized surface of 50 nm diameters, followedby oxidation with horseradish peroxidase (HRP) enzyme and its cofactorH2O2. All reaction steps were monitored by UV-Vis-NIR spectroscopy includ-ing in situ detection of the polymerization process. UV-Vis-NIR, Cyclicvoltammetry (CV) and surface enhanced Raman scattering (SERS) measure-ments supported the formation of a nanoshell of PANI on the AuNP core. Two templates for anilinium assembly were compared revealing a strongdependence of the enzymatic kinetics on the template. The kinetic study hadshown that the rigid template of the AuNP contributes to higher reaction rateon the AuNP compared with the more flexible polyanion template. The mildreaction condition enables an easy and precise method for obtaining PANInano-shell on anionic templates for advanced bioelectronic applications

The depleting fuel resources and elevated air pollution are raising serious concerns among the global population. The fuel prices are also increasing day by day. Hence the world is more focused on maximizing conventional energy resources like solar, tidal, wind energies, etc. However, for the fullest utilization of conventional energy sources, we need efficient energy storage systems, and currently, we are using batteries as the primary energy storage elements. Nowadays, researchers are giving utmost importance to the development of supercapacitors. Graphene coming under carbon groups and polyaniline (PANI), coming under electronic conducting polymers (ECP), are two different materials mainly used for supercapacitor electrode fabrication. The normal route for synthesizing graphene-PANI composites is a time-consuming process. Here we present a simple route for synthesizing graphene-PANI composites. The same method can be adopted for fabricating modified graphene-PANI composites too. The FTIR, Raman spectroscopy, XRD, SEM, and TEM results showed that the formation of graphene-PANI composites in the current route is the same as that of the normal method. Moreover, the cyclic voltammetry (CV) and charge–discharge (CD) tests revealed excellent electrochemical performance and cyclability. The CV study reported that the specific capacitances of the supercapacitor are 235, 179, 120, 85, and 55 F/g at scan rates of 10, 20, 50, 100, and 200 mV/s. The capacitance retention ratio was more than 90% and the ESR was found to be 10.5 O.

Quasi-two-dimensional (q2D) conducting polymer thin film synergizes the advantageous features of long-range molecular ordering and high intrinsic conductivity, which are promising for flexible thin film-based micro-supercapacitors (MSCs). Herein, we present the high-performance flexible MSCs based on highly ordered quasi-two-dimensional polyaniline (q2D-PANI) thin film using surfactant monolayer assisted interfacial synthesis (SMAIS). Owing to high electrical conductivity, rich redox chemistry, and thin-film morphology, the q2D-PANI MSCs show high volumetric specific capacitance (ca. 360 F/cm3) and energy density (17.9 mWh/cm3), which outperform the state-of-art PANI thin-film based MSCs and promise for future flexible electronics.

The simplification of localized surface plasmon resonance (LSPR) detection can further promote the development of optical biosensing application in point-of-care testing. In this study, we proposed a simple light emitting diode (LED) based single-wavelength LSPR sensor modulated with bio-electron transfers for the detection of electroactive biomolecules. Indium tin oxide electrode loaded with nanocomposites of polyaniline coated gold nanorod was used as LSPR chip, and the applied electric potential was scanned at the LSPR chip for single-wavelength LSPR biosensing. Under the scanning of applied potentials, biological electron transfer of redox reaction was employed to demonstrate the bioelectronic modulation of single-wavelength LSPR for selective electroactive biomolecule detection. Without any additional recognition material, electroactive biomolecules uric acid and dopamine were detected directly with a sensitivity of 5.05 μmol/L and 7.11 μmol/L at their specific oxidation potentials, respectively. With the simplified optical configuration and selective bioelectronic modulation, the single-wavelength LSPR sensor is promising for the development of simple, low-cost, and high specificity optical biosensor for point-of-care testing of electroactive biomolecules.

Metal organic frameworks (MOFs) have been considered as compelling precursor for miscellaneous applications. However, their unsatisfied electrocatalytic performance limits their direct application as electrocatalyst. Herein, by incorporating the cobalt-oxide bonds and polyaniline (PANI) with two-dimension zeolitic imidazolate frameworks (ZIFs), a novel bifunctional catalyst (Co-O-ZIF/PANI) for Zn-air battery was designed based on a facile and eco-friendly method. This Co-O-ZIF/PANI with optimized surface adsorption effect and suitable Co3+/Co2+ ratio, exhibits eminent electrocatalytic activity toward both oxygen reduction and evolution reaction. The as-assembled liquid ZABs based on Co-O-ZIF/PANI achieves a remarkable maximum power density of 123.1 mW cm-2 and low discharge-charge voltage gap of 0.81 V at 5 mA cm−2 for over 300 cycles. Operando Raman spectroscopy reveals that the excellent performance origins from the optimized surface chemisorption property of O2 and H2O brought by Co–O bonds and PANI. This work provides a novel prospect to develop efficient MOF derived bifunctional electrocatalysts by optimizing surface chemisorption properties.

In this study, single crystal ZnO microwires (MW) with size of ∼5.4 mm × 30 μm are prepared through a chemical vapor deposition technique at high temperature (1200 °C). Subsequently, p-type conducting polyaniline (PANI) polymers with different conductivities are densely coated on part of the ZnO MW to construct organic/inorganic core-shell heterojunction photodetectors. The hetero-diodes reach an extremely high rectification ratio (I+3V/I-3V) of 749230, and a maximum rejection ratio (I350nm/Idark) of 3556 (at -3 V), indicating great potential as rectified switches. All the heterojunction devices exhibit strong response to ultraviolet (UV) radiation with high response speed. Moreover, the obvious photovoltaic behavior can also be obtained, allowing the device to operate as an independent and stable unit without externally supplied power. Under 0 V bias voltage, the self-powered photodetector shows a maximum responsivity of 0.56 mA W−1 and a rapid response speed of 0.11 ms/1.45 ms (rise time/decay time). Finally, a finite difference time domain (FDTD) simulation is performed to further demonstrate the interaction mechanism between the incident light field and the hexagonal cavity, which strongly supports the enhancement of the light absorption in whispering-gallery-mode resonator.

In the present study, composites of Polyaniline and some fruit peels were synthesized in various conditions and used for lead removal from aqueous solutions. Adsorption tests were conducted in batch mode using the most efficient adsorbent, and the effects of medium pH, initial lead concentration, contact time, adsorbent dosage, and adsorption isotherms were investigated. The results showed that all composites were more efficient in lead removal compared to the fruit peels alone. The highest removal percentage was related to the composite of banana peel and Polyaniline that synthesized in the aqueous solution in the presence of 2 g·L−1 Poly ethylene glycol. This composite showed 95.96% lead adsorption at pH=6, the contact time of 90 min, the initial lead concentration of 25 mg·L−1, and an adsorbent concentration of 8 g·L−1. Adsorption isotherm study showed that adsorption of lead by synthesized composite could be fitted by both Langmuir and Freundlich models, but the Langmuir model was more fitted than Freundlich. Besides, some characteristics of the composites, such as chemical composition (XRD analysis), structure, and morphology (SEM analysis) and functional groups (FTIR analysis), were studied.

The homogeneous distribution of nano-sulfur onto 3D structures for the development of high-performance Li-S batteries (LSBs) is a top concern to solve the low utilization of sulfur, sluggish redox kinetics, and lithium polysulfide (LiPS) shuttle effect. Herein, a novel “egg tray” hierarchical architecture of confining and uniformly distributing nano-sulfur into a 3D holey graphene (HG) framework with polyaniline crosslinking (3DHG/NS/CPANI) via photo-assisted method was designed for high-mass-loading LSB cathode. Notably, HG contains both conductive skeletons as electron transfer paths and abundant void spaces in favor of homogenous sulfur anchoring. This configuration improves the contact between nano-sulfur and graphene for effective charge transportation and provides buffering space for volume variations during electrochemical processes. Moreover, a facile photo-assisted method was developed to cross link HG with polyaniline to act as an efficient polysulfide adsorbent, allowing nano-sulfur (NS) to be firmly embedded into the holes of graphene through physical and chemical effects, thus prohibiting the dissolution and shuttle effect of polysulfide. Considering these advantages, the prepared 3DHG/NS/CPANI electrode exhibited excellent performance with high sulfur utilization and specific capacity, resulting in specific discharge capacities at 0.5 and 1 C of 1082 and 921 mA h −1, respectively, and small capacity decay of 0.04% per cycle over 500 cycles at 1 C. The strategy in this work, which synergistically combines morphology control, nano-sulfur positioning, and structural engineering to enhance the electrochemical performance for Li−S batteries, will offer a valuable reference to energy storage and conversion advances.

Clean and sustainable energy is of one prime interest to current water production demands. Producing unpolluted drinking water and sustainable energy is the next big challenge to overcome. Solar steam generation has great future potentials for mankind. The need to overcome limitations of solar steam generation is in recent penchants. A highly efficient black photo-convertor nanomaterial is synthesized and functionalized to achieve 87% efficiency under one Sun (1kW.m-2) illumination. The black tin oxide (bSnO) nanomaterial was synthesized using electrocatalytic reduction approach, resulting a robust photo-convertor nanomaterial. To enhance the capabilities of water evaporation, polymerization was performed using PANI (polyaniline), and PPy (polypyrrole) referred to as bSnO@PANI and bSnO@PPy, respectively. Various physical factors as narrow bandgap, surface water ratios and localized heating are found remarkable to enhance overall efficiency. The bSnO@PANI was assessed to be at highest elevated temperature by acquiring nearly ∼82 °C in close to 100 seconds under one sun irradiance and nearly ∼56 °C when in contact with water body. Thus, final water evaporating rate recorded to be 2.04 kg.m-2 h-1 and 1.74 kg.m-2 h-1 for water and seawater, respectively. Producing drinking water from Dyed and sea-water are reported after solar evaporation. Achieving enormous evaporation rate can further be explored for green energy generation.

A plasmonic Cu6Sn5/polyaniline (Cu6Sn5/PANI) nanocomposite was synthesized by chemical reduction and hydrothermal methods. The best photocatalytic overall water splitting performance was achieved by the Cu6Sn5/PANI3wt% composite, which contains 3 wt% PANI, which is approximately three times more than that of pure Cu6Sn5. Meanwhile, Cu6Sn5/PANI3wt% exhibited excellent photocatalytic stability for water splitting during the stability investigation. The dramatic promotion of the photocatalytic activity performance can be ascribed to the cocatalyst PANI. The existence of PANI can remarkably promote the separation and transfer efficiency of the photoinduced electron-hole pairs, and therefore enhance the photocatalytic activity. Our results also verify that the photogenerated charge comes from plasmonic Cu6Sn5 with the surface plasmon resonance (SPR) effect, which is different from traditional semiconductor-based photocatalysts. This work sheds some light on plasmonic photocatalyst development and provides an alternative pathway for photocatalytic reactions.

Carbon-based conductive and electroactive materials (e.g., derivatives of graphene, fullerenes, polypyrrole, polythiophene, polyaniline) have been studied since the 1970s for use in a broad range of applications. These materials have electrical properties comparable to those of commonly used metals, while providing other benefits such as flexibility in processing and modification with biologics (e.g., cells, biomolecules), to yield electroactive materials with biomimetic mechanical and chemical properties. In this review, we focus on the uses of these electroconductive materials in the context of the central and peripheral nervous system, specifically recent studies in the peripheral nerve, spinal cord, brain, eye, and ear. We also highlight in vivo studies and clinical trials, as well as a snapshot of emerging classes of electroconductive materials (e.g., biodegradable materials). We believe such specialized electrically conductive biomaterials will clinically impact the field of tissue regeneration in the foreseeable future. Statement of significance This review addresses the use of conductive and electroactive materials for neural tissue regeneration, which is of significant interest to a broad readership, and of particular relevance to the growing community of scientists, engineers and clinicians in academia and industry who develop novel medical devices for tissue engineering and regenerative medicine. The review covers the materials that may be employed (primarily focusing on derivatives of fullerenes, graphene and conjugated polymers) and techniques used to analyze materials composed thereof, followed by sections on the application of these materials to nervous tissues (i.e., peripheral nerve, spinal cord, brain, optical, and auditory tissues) throughout the body.

Harmless and breathable flexible humidity sensor has important applications in continuous and real-time detection of human physiological activities. In this work, with hydrophobic poly (vinylidene fluoride) (PVDF) membrane as both the template and substrate and cetyltrimethylammonium bromide as a structure regulator, polyaniline (PANI) was unilaterally deposited on a PVDF microporous membrane to facilely fabricate a single-sided integrated flexible humidity sensor (IFHS). Such IFHS is featured with unique micro/nano structure and good air permeability. Moreover, it exhibits good humidity sensing properties at room temperature including fast response, small hysteresis and stable response even under bending deformation. The flexible sensor could realize non-contact monitoring of human respiration and speaking activities. Unilateral deposition of PANI and good breathability of IFHS avoids direct contact between PANI and human skin, thus averting harms to human and minimizing the deterioration of humidity sensing properties of PANI layer. The simple method is universal to the preparation of single-sided, integrated, breathable, nontoxic and fast response wearable humidity sensors based on PANI and hydrophobic microporous polymer membranes, offering useful references for the construction of advanced flexible sensors.

The band gaps of three forms of polyaniline (PANI) are calculated using the DFT method with the B3LYP functional and SV(P) basis set. This marks the first time that the band gap for this polymer has been calculated using this DFT method. The calculations include an investigation of the effect of varying the benzoid–quinoid structural units, the effect of increasing oligomer length, and the inclusion of Michael’s addition structures, which could be residual in the polymer depending on the chosen synthetic method. All results were compared with the experimentally determined band gap of 1.5 eV as typically reported in the literature. A commonly used structural motif of alternating benzoid–quinoid units and a ratio of 0.5:0.5 benzoid–quinoid resulted in a computed band gap of 1.9 eV. Inclusion of one extra quinoid unit gave rise to a band gap of 1.3 eV. Incorporation of a Michael’s addition structure was found to dominate the band gap calculation, yielding a localized LUMO and a band gap of 1.3 eV that was insensitive to the polymer chain length and composition.

In order to improve the anticorrosive performance of waterborne epoxy (WEP) coating, small amounts of polyaniline (PANI) were blended under ultrasonic irradiation to obtain PANI/WEP composite coatings with high dispersibility of PANI particles. The PANI/WEP composite coatings were characterized by Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). Their adhesive force level and hardness grade were tested based on the Chinese National Standard GB/T9286-1998 and GB/T6739-1996, respectively. These results indicated that, compared to the pristine WEP coating, the addition of PANI with suitable content could completely fill the micropores or microcracks and remarkably improve the hardness grade of composite coatings. The electrochemical impedance spectra (EIS) and Tafel polarization curves revealed that the addition of PANI not only could increase the impedance arc, but also could increase the impedance modulus at low frequency. Then, the salt spray tests were employed to observe the anticorrosive performance of PANI/WEP composite coatings. Finally, the enhanced anticorrosive mechanism of WEP coating by the addition of small amounts of PANI was proposed and discussed. The addition of PANI with suitable content could play an important role of physical and chemical barriers to improve the anticorrosive performance of waterborne epoxy coating.

In this present research work, we presented a new Bottom Gate P-Type Organic Field Effect Transistor (OFET) humidity sensor and its applicability towards humidity has been experimentally demonstrated. P-type organic semiconductor polyaniline (PANI) has been used in a variety of applications, including logic circuit components, electromagnetic shielding, chemical sensing, and anticorrosion. Humidity sensor can be used to monitor relative humidity (RH) in various environments. We only focus on the fabrication of conducting polymer OFETs with top contact to measure humidity and verify I-V properties. The current saturation (ISat) of p-type OFETs was 0.8 μA, while the threshold voltage VTh was 2.2V. The results of FESEM have been perform to confirm that deposited thin film grown on the substrate is purely uniform. The Proposed sensor shows that organic gate dielectrics are a low-cost alternative to inorganic gate dielectrics with good electrical performance. The proposed OFET-based sensors have a number of benefits, such as high sensitivity, low cost, quick response, and physical flexibility.

Clay mineral obtained from Tuticorin in Tamilnadu, India (Indian Clay- IC) was purified and used to synthesise polyaniline-Indian clay nanocomposites (Pani-IC NCP) by polymerising aniline with the clay by chemical oxidation method using potassium perdisulphate as oxidant and by varying the aniline to clay ratio. The formation of composite in nanoscale was confirmed by XRD and TEM analysis. The in situ intercalative polymerization of monomer within the clays was ascertained by FTIR, UV–visible, XRD, SEM and TEM studies. The analyses of UV visible and FTIR spectroscopy demonstrated that aniline has been polymerized to Pani in its conducting emeraldine form. The conformation adopted by Pani Chains in the clay interlayer depended on the molar ratio of aniline to clay. SEM analysis showed the variation in morphology from granular agglomerate to layered flaky structure as the clay concentration was increased. Thermal stability of the nanocomposites was studied using TGA/DTA and DSC studies and it was found that they showed better thermal stability than their pristine polymers indicating the enhanced barrier property of the nanoclay. XRD showed that the clay host used accommodates higher amount of emeraldine salt than MMT. The Cyclic voltammetry studies of the synthesized nanocomposites showed the one with 0.5 g clay showed better electrochemical response. It exhibited good adherent behaviour on electrode surface at pH 1.0 with two oxidation peaks at 463 and 672 mV and two reduction peaks at 360 and 126 mV. By varying the atmosphere it was found that the nanocomposite modified electrode exhibited oxygen reducing capacity than their Bentonite counterpart. Chronoamperometric and Chronocoulometric studies were also carried out at inert as well as oxidising atmosphere which confirmed the above fact. EIS studies of the modified electrodes showed double layer capacitance value of 5.95 × 10−8 Fcm−2 with the bode phase angle of 70°.

Flexible carbon nanofibers networks (FCNNs) play a crucial role in flexible and portable energy storage devices. Doping conductive and reactive N-atoms can enhance charge transport and transfer properties vital for high energy storage and high power. However, synchronous-ultrahigh conductive-reactive N-atoms doped FCNNs (SH-FCNNs) are still challenged by the N-atoms instability at high temperatures. To resolve this problem, an in-situ synergistic-carbonization-nitridation strategy is reported using polyaniline (PANI) implanted highly porous polyacrylonitrile nanofibers as a precursor. The obtained SH-FCNNs were doped with 5.9 at% conductive and 4.73 at% reactive N-atoms. They exhibit a superhigh specific capacitance (580.9 F g−1@0.5 A g−1) and high-rate capability (307.2 F g−1@128 A g−1). The flexible solid-state supercapacitors can output specific energy and power density of 18.3 Wh kg−1 and 16.9 kW kg−1. As for flexible solid-state Zn-ion batteries, the constructed SH-FCNNs@PANI cathodes have specific energy (290 Wh kg−1@0.159 kW kg−1) and supercapacitor-like power performance (128.1 Wh kg−1@23.3 kW kg−1). The synergistic effects of ultrahigh conductive and reactive N-atoms promote these performances to reach the mountaintop of flexible solid-state energy storage devices. The novel strategy also presents new insights on designing high-performance FCNNs for electrochemical energy storage, catalysts, and sensors.

Polyaniline (PANI)-based networks combined with Fe3O4 hollow spheres and carbon balls (FCP) for improved electromagnetic wave (EMW) absorption were investigated using an easy-to-industrialize solvothermal and physical method. Hollow structure Fe3O4 spheres with a lower density than that of the common solid sphere were prepared. As a thin and light magnetic material, Fe3O4 hollow spheres generate magnetic loss, carbon balls and PANI networks generate dielectric loss. The magnetic and conductive parts play appropriate roles in achieving complementarity in the EMW absorption. The relatively high specific surface area introduced by PANI networks promotes interfacial polarization and further supports dielectric loss. In conclusion, the above reasons provide multiple attenuation mechanisms. Samples FCP1 (−65.109 dB, at 12.800 GHz, 1.966 mm, from 5.6 to 18.0 GHz) and FCP2 (−61.033 dB, at 8.480 GHz, 3.328 mm, from 4.3 to 18.0 GHz) demonstrated a wide bandwidth, a small thickness, a minimum reflection loss (RL), and a low loading ratio (25%) in paraffin-based composites. Specifically, their loading ration of 25% is much lower than the loading ratio of conventional materials (usually 50% and above). In addition, the bandwidth is excessively wide, above 12 GHz, possessing good absorption performance in continuous intervals with different thicknesses. Such excellent characteristics have rarely been reported in literature.

This research paper presents the synthesis and characterization of polyaniline (PANI) and PANI/Copper oxide (PANI/CuO) nanocomposites. PANI was synthesized using chemical a route and PANI/CuO Nanocomposite was prepared using mechanical mixing method. The prepared samples were characterized for FTIR, XRD, SEM, Electrical conductivity using four probe method and methanol gas sensing properties. FTIR spectra confirm the presence of characteristics peaks of PANI. XRD spectrum indicates the presence of copper oxide nanoparticles in PANI and SEM micrographs indicate the distribution of copper oxide nanoparticles in PANI matrix. Electrical conductivity of PANI has been decreased in the presence of different weight percent of CuO. Gas sensing of the response of PANI-CuO was observed higher compared to pure PANI.

Ferrites are ceramics having Fe (III) ions. Cobalt ferrite was doped with bismuth via sol–gel method. The doped samples were mixed with polyaniline to form the composites. Polyaniline was chosen as it was a cheap material. Sol–gel method is a time saving and simple method. It also brings about the homogeneity in the reaction. The synthesized material was calcinated at 900 °C for 6 h. Preparation of polyaniline was done by oxidative polymerization method. Here ammonium persulphate act as an oxidative agent. The polyaniline was washed with methanol and dried for 24 h in an oven. The composite of bismuth doped cobalt ferrite and polyaniline were studied through X-ray diffraction (XRD), FTIR, UV, VSM and FESEM. It was observed that magnetic and optical properties changed with change in amount of dopant.

Dye-sensitized solar cells (DSSCs) associated to the class of thin-film solar cells which have been under recent research work for more than two decades due to their low cost, simple preparation technology, low energy consumption, roll-to-roll manufacturing, eco-friendly, durable and light weight. Dye-sensitized solar cells (DSSCs) were fabricated using TiO2 as the photo anode and the composite of PANI and FeS2 as a counter electrode. The effect of the contents on the DSSC performance was investigated by adjusting the ratios of PANI and FeS2. It was found that the optimized DSSC efficiency of 0.9 % to 2.02% was achieved. The structure, surface morphology, elemental composition and functional groups of the PANI and FeS2 composites were characterized by XRD, SEM, TEM and FTIR analysis. This article provides an in-depth discussion on fabrication of DSSC based on polyaniline/FeS2 composite as counter electrode, operating conditions, prospective efficient materials and FTIR characteristics. From the obtained results, the composites of PANI and FeS2 counter electrode is served as an efficient, low-cost counter electrode (CE) material for dye-sensitized solar cells (DSSCs).

Self-healable aqueous batteries can improve their service lifetime and solve safety issues induced by device failure during large deformations at room temperature. At low temperatures (e.g. -20 °C), they generally lose most of their electrochemical performance and self-healing function since water molecules in aqueous electrolytes are inevitably frozen. Herein, a simple and effective method is adopted to prepare an anti-freezing and self-healable polyelectrolyte (AF-SH CPAM) by the in-situ polymerization of acrylamide monomer in a water/ethylene glycol solution. In AF-SH CPAM, ethylene glycol simultaneously achieves the anti-freezing and self-healing performance of the polyelectrolyte by restraining the icing of water molecules and dynamically adjusting the molecular interactions between polymer chains and water. Based on this polyelectrolyte, a self-healable zinc ion battery working at -20 °C is fabricated for the first time by using the gold-sprayed carbon nanotube/polyaniline film as cathode and the zinc foil as anode. This battery can deliver a high specific capacity of 233.9 mAh g − 1 at room temperature, exceeding that of those reported aqueous Zn/polyaniline batteries. More impressively, it also shows the prominent self-healablity with a high capacity retention of 90.4% after three cutting/self-healing cycles at -20 °C, presenting a breakthrough in low-temperature self-healing function of aqueous batteries.

Transition metal dichalcogenides (TMDCs) are two dimensional nanomaterials made up of a monolayer of transition metal atoms sandwiched (X-M-X) between two layers of chalcogen atoms in a hexagonal lattice. Molybdenum di sulfide (MoS2) have attracted much attention among the TMDCs family and is a suitable electrode material for supercapacitors. It has remarkable physical and chemical properties such as large surface area, sheet like structure, superior capability and lower rates of cyclic induced degradation. However, MoS2 suffers from lower electronic conductivity that limits its energy storage. Hence the conducting polymer, polyaniline is doped with the MoS2 to overcome the deficiencies and to enhance the electrochemical performance. A novel microwave assisted method is implemented to synthesize MoS2/PANI nanocomposites for the strategy of supercapacitors. The microwave assisted processing of MoS2/PANI nanocomposites provides several advantages than the conventional heating method such as tuning the physiochemical properties as reduction of impurity, mono dispersivity in the morphology that results in enhancing the electrochemical performance. The phase purity, homogeneity, and functional groups present in the MoS2/PANI nanocomposites are synthesized and characterized by X-ray diffraction (XRD), Field Emission Scanning Electron microscope (FESEM), High Resolution Transmission Electron Microscope (HR-TEM), Fourier Transform infrared spectroscopy (FT-IR), UV–Visible (UV–Vis) absorption spectroscopy and Raman spectroscopy. The optimized MoS2 /PANI nanosheets exhibits a high specific capacitance of 348 F/g at 0.5 A/g and MoS2/PANI nanocomposites retains 89.21% of its initial specific capacitance even after 2000 cycles. Hence the strategy of microwave assisted synthesis of MoS2/PANI nanocomposites improve the electrochemical performance of two dimensional MoS2 based electrode materials for energy storage.

Several approaches have recently been investigated with the aim of enhancing the specific capacitance of polyaniline (PANI). We herein report a novel pathway to boost the specific capacitance of PANI, which is highly tunable and versatile, based on wet chemistry techniques. In this approach, utilization of a specific metal-organic framework (MOF), UiO-66-NH2, as a nanopore generator (Nanogen) is demonstrated. This systematic study demonstrates a tight interplay between the enhanced electrolyte accessibility to the PANI chains, through the incorporation of MOF nanogens, and the optimal relative amount of the conductive PANI, necessary to attain a charge percolation threshold in the binary system (MOF@PANI). Satisfying the charge percolation while maintaining porosity is necessary to arrive at a maximized specific capacitance of the PANI as the active phase. The enhancement in the specific capacitance of the PANI was fully exploited through a systematic investigation that helped to pinpoint the saddle point at which the two orthogonal properties, namely porosity (electrolyte diffusivity) and charge mobility (PANI inter-chain electronic conductivity) can be fine-tuned via controlling the materials composition. Of the different compositions investigated, the composite containing 23 wt% PANI of the total weight, doped with MOF nanogens, resulted in an enhanced specific capacitance of 872 F g-1 for the PANI, in comparison to only 469 F g-1 for the pristine PANI investigated under identical conditions.

Conducting polymers such as polyaniline have demonstrated their considerable superiorities when serving as promising sulfur host materials for Li-S batteries, owing to their strong affinity for lithium polysulfides (LiPSs) and excellent conductivity. However, less polar groups, unstable frame structure and low specific surface area limited their electrochemical performance. Herein, a covalent organic framework (COF)-like conjugated microporous polyaniline (CMPA) with extended -conjugated system and permanent 3D microporosity was developed as modified material using in the current collector of sulfur cathode for highly efficient Li-S batteries. This multifunctional CMPA shows the integrated nature of conjugated microporous polymers (CMP) and PANi, ensuring exceptionally specific surface area, nitrogen-rich property, stable framework and high conductivity. Attributed to these superiorities, the current collector modified by CMPA delivers a high areal capacity (7.42 mAh cm-2) and high energy density (202.8 Wh kgcell-1) even under the sulfur loading of 8.72 mg cm-2. These outcomes present new strategy for designing advanced cathode and also demonstrate the potential of CMPs in energy storage batteries.

Conducting polyaniline (PANI) is doped with a bi-metal oxide, Zinc tungstate (ZnWO4) in the chemical polymerization method, and the composite matrix is sintered on the substrate to form a film. The characterization of composite by FTIR spectrum to confirm the formation of emeraldine salt phase of PANI from monomer aniline. X-RD spectra and SEM images to confirm the presence of crystalline ZnWO4 in PANI matrix. The difference in conductivity versus temperature shows exponentially thermal activated behavior, in which conductivity increases with temperature due to the curling effect of polymer composite. When exposed to liquid petroleum gas (LPG), due to depletion in the number of conduction electrons at the surface and grain boundaries, there is a barrier formation at the interface of sensing films of PANI/ZnWO4 composite, via Fermi energy exchange control mechanism, thereby composite film increases its resistance with LPG concentration.

Nano composites of conducting polyaniline with ZnS nanoparticles (PANI/ZnS) have been synthesized by in-situ polymerization of aniline monomer using ammonium persulphate as oxidizing agent. The formation of PANI/ZnS composites was assessed by UV–Vis spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscope (FTIR), Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM) and X ray diffraction analysis (XRD). FTIR and UV studies provided the information of functional group and optical behavior respectively SEM studies shows the well dispersion of ZnS Nanoparticles in the polyaniline matrix. Size determination identified and confirmed by TEM analysis.

The rigidity and discomfort associated with the use of conventional semiconductor-based wearable devices has prompted increasing interest in hydrogel-based devices. Hydrogels have properties similar to human skin tissue and therefore are more comfortable to use. The present study reports a high-performance, piezoresistive hydrogel nanocomposite-based wearable device towards human motion sensing. The nanocomposites comprise of an optimized distribution of polyaniline (PANI) decorated thermally exfoliated graphene oxide (TEGO) nanofillers incorporated within a biopolymer matrix. The engineered nanofillers endow the hydrogel with synergistic improvement in mechanical and electrical properties, resulting in a combination of high electrical conductance and extraordinary mechanical performance. The material demonstrated high stability during fatigue cycling done for extended periods. Furthermore, these nanostructured materials were used to prepare wearable sensors towards human motion detection. These advanced sensors exhibit a stable, sensitive and repeatable electrical response. Moreover, the use of fully biodegradable raw materials, simple synthesis method, and easy scalability establish the significant potential of the developed material towards wearable devices.

Conducting polymers are an outstanding class of materials characterized by electroconductive properties that make them good candidates for applications in several sectors. Among them, polyaniline (PANI) is unique for its extraordinary ability to conduct electricity, biocompatibility, and low toxicity. In spite of its surprising features, to date, PANI has not found application in practical uses due to its low solubility and processability. In order to overcome these limitations, different approaches have been developed, such as polymer grafting processes, PANI-based composites, and blends preparation. The present review describes the most recent advances on PANI applications in biomedical fields, such as antioxidant, antimicrobial and antivirus activity, drug delivery, cancer therapy, etc. In this article, synthetic procedures are also reported which are crucial for the realization of more innovative materials in the future.

Aqueous Zn-ion batteries (AZIBs) are promising candidates for large-scale energy storage owing to their intrinsic safety and low cost. However, the formation of Zn dendrite caused by uneven deposition on Zn anode severely impedes the lifespan of AZIBs. Herein, we propose a green and low-cost additive, nettle extract (NE), to guide the uniform Zn deposition via in-situ engineered zincophilic sites. We show by both experiments and theoretical calculations that the zincophilic molecules contained in NE can adsorb on Zn anode surface to offer more effective sites for Zn nucleation, thus effectively suppressing the dendrite growth. Significantly, the Zn||Zn symmetric cell with NE can stably cycle over 2200 h at 5 mA cm−2 with 5 mAh cm−2 capacity. A Zn||polyaniline/carbon felt full cell also gains 84.9% capacity retention after 1500 cycles. Our strategy of engineering zincophilic sites on Zn anode via plant extracts additives ushers in new possibilities to develop dendrite-free Zn anode.

Flexible supercapacitors with high areal energy density are promising energy storage devices to meet the increasing demands for wearable and portable electronic products. Herein, three kinds of flexible electrodes were fabricated electrochemically through tuning spatial distribution of graphene sheets composited with polyaniline (PANi) nanofiber array on carbon cloth, in which graphene sheets were used as the efficient growing substrate or protecting layer for the arrays and directly inserted into the arrays. It is found that the charge storage ability of all the PANi arrays could be enhanced significantly that depended greatly on the spatial distribution of graphene sheets composited with the array. The composite electrodes composing of graphene inserted PANi array on the graphene covered carbon cloth possesses the highest areal energy density among all the electrodes. More clearly, the corresponding all−solid−state supercapacitor devices can reach outstanding performances with a maximum energy density of 313 μWh cm−2 and capacitance retention of 92.7% after 5000 cycles could be achieved in the electrolyte containing Fe3+. This work is believed to provide a new thought for fabricating cost–effective and flexible electrodes with ultrahigh areal energy density, excellent flexibility and cycle stability endow for high−energy wearable/portable energy storage devices.

Supercapacitors with excellent electrochemical performance are considered the most promising candidates to meet the increasing energy demand. Herein, we developed a novel electrode material for supercapacitors, polyaniline (PANI)-3-aminopropyl triethoxysilane (APTEs)-titania nanowires (TNW), which was synthesized on potassium doped titanium foil via a simple two-step procedure. In the composite, the nano-mesh structure formed by APTEs-coated TNW serves as the framework for the growth of PANI nanoparticles, and PANI nanoparticles act as the electrochemically active part. The specific capacitance of PANI-APTEs-TNW of up to 315.16 mF cm−2 at 0.2 mA cm−2 in 1.0 M H2SO4 solution is achieved, while that of PANI-TNW is 271.67 mF cm−2. Meanwhile, the capacitance retention rate of PANI-APTEs-TNW is 86.8% after 1000 cycles under 1.5 mA cm−2. Compared to PANI-TNW, the better capacitive behavior of PANI-APTEs-TNW is attributed to the anchoring effect of APTEs, which is highly interactive and exhibits compact structures between the TNW and PANI nanoparticles, resulting in a stable structure during the rapid charge-discharge process. This strategy is characterized by its good electrochemical properties, simple equipment, low cost of raw materials, and large-area preparation. Thus, our findings provide an effective method for the design of high-performance supercapacitors and promote their practical applications.

As a sustainable and eco-friendly technology, the benthic microbial fuel cell (BMFC) has been emerged as alternative and potential approach to recover electrical energy by microorganisms, but lower power density and poor long-term life hinder their practical application. Modification of anodic materials is an efficient strategy to solve this problem. Here, a conductive and biocompatible hydrogel electrode, polyaniline-polypyrole-CNTs-Fe3O4 (PANI-PPy-CNTs-Fe3O4) is prepared and applied as anode in a simulated BMFC. The maximum power density of the BMFC with PANI-PPy-CNTs-Fe3O4 hydrogel anode (5901.49 mW/m3) is 1.33, 2.15 and 2.06 times higher than that of PANI-PPy (4413.03 mW/m3), PANI and PPy anodes (2737.12 and 2859.53 mW/m3), respectively. The charge transfer resistance of quaternary hydrogel bioanode in BMFC (3.922 Ω) is much lower than that of the PANI (8.682 Ω), PPy (8.262 Ω) and PANI-PPy (5.772 Ω) hydrogel bioanodes. Moreover, the extracellular electron transfer ability is also enhanced on the composite hydrogel anode, which also exhibits the high biomass. High-throughput sequencing technology indicates that the synergistic effect of bacteria on the quaternary hydrogel made full use of organic matter as available fuel to enable a high electricity-generation anode. Such foregoing mainly ascribed to the composite hydrogel keep the high biocompatibility from components, while the addition of CNTs and Fe3O4 dramatically decreases the internal resistance and provides more electrochemical active surface area on basis of macroporous 3D hydrogel structure. This work explores the composite hydrogel used as anodes to construct high-performance BMFC and provides significant information for the applications of actual BMFCs in the future.

The high concentrations of heavy metal ions in industrial effluents are one of the most challenging wastewaters to deal with. In this study and in order to change the inner diameter of the halloysite nanotubes (HNT), their internal surface was coated by different polymers (polydopamine, polyaniline and polystyrene) and then, the modified nanotubes were incorporated in the polyamide thin film NF membrane for the treatment of metal ions solutions. Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) studies indicated that the internal coating was successful. Furthermore, the neat and modified nanofiltration (NF) membranes were characterized in terms of morphology, contact angle, water flux and metal ion rejection. The modified membranes displayed lower contact angle values (29.4% reduction) that can be linked to the hydrophilic groups in the structure of the coated polymers and the smoother surface of the thin film nanocomposite (TFN) membrane. In addition, the permeation fluxes of the modified membranes were improved significantly (33.4% improvement) without any major reduction in their ion rejection; that shows HNTs act as the channels to transfer water through the membrane structure while the coating of the inner surface of HNT reduces the size of the channel and makes more repulsion and steric hindrance for the ion to pass through the nanotubes. Among the fabricated membranes, the NF membrane with 0.05 wt% polystyrene-coated HNT showed the lowest contact angle (55.30o) and the highest water permeation flux (27.51 L m-2 hr-1), compared to the neat TFC membrane (15.26 L m-2 hr-1) and the NF membrane with 0.05 wt% unmodified HNT (20.62 L m-2 hr-1).

The electrochemical method is the most effective, facile, and economical approach for the detection of small molecules. The present article deals with the design and engineering of polymer–graphene-based thin films through an in situ facile synthesis technique for the development of high performance electrochemical sensors. We report a facile technique for preparing polyaniline (PANI) and polyaniline/graphene (PANI/G) nanocomposite thin films and their application as enzyme-free electrochemical sensors for hydrogen peroxide (H2O2). PANI and PANI/G films were deposited on a dopamine modified ITO substrate via spin coating and in situ deposition techniques. The in situ fabricated films, which exhibited better electrical properties and stability as compared to the spin coated films, were studied in detail. These thin films were characterized using UV-visible spectroscopy, FT-IR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM) to study their optical, chemical, and surface textural properties. Results show a homogeneous distribution of the constituting materials. From the AFM results, it was found out that the PANI/G film showed increased surface roughness (∼20 nm) as compared to the PANI film (∼15 nm). The electrochemical properties of the films were determined using the van der Pauw method and cyclic voltammetry technique. The conductivity of the PANI and PANI/G films was estimated to be 5.38 × 103 and 6.84 × 103 S cm−1, respectively. Finally, the electrochemical sensing performances of the PANI and PANI/G films were investigated towards H2O2 reduction in a wide potential range of −0.6 to 0.6 V in 0.1 M PBS solution of pH 7.0. This work demonstrates the application of thin-film technology for the development of nanodevice sensors.

Polyanilines doped with different concentrations of oxalic acid have been synthesized by oxidative chemical polymerization using potassium perdisulfate as oxidizing agent. The effect of dopant on the kinetics of polymerization has been studied by UV–VIS spectroscopy. The presence of oxalic acid in the polymer has been studied by FTIR, and morphology by SEM and TEM. The thermal stability of the polymer was investigated by TGA and degree of crystallinity of polyaniline was studied by XRD. The electrochemical behaviour has been studied by cyclic voltammetry (CV) and the phenomenon of charge transport and capacitance was examined by Electrochemical Impedance Spectroscopy (EIS). The morphological study shows the particles to be of nanosize and EIS studies show that these samples have significant double layer capacitance (Cdl) and can be used as capacitors.

Zinc oxide nanoparticles were synthesized through wet chemical method. Polyaniline was synthesized by oxidative polymerization of aniline using potassium perdisulphate as oxidizing agent. Polyaniline -Zinc oxide nanocomposites were prepared by five different percentages of zinc oxide nanoparticles mixed with synthesized polyaniline. The prepared metal oxide, polymer and Nano composites were characterized by UV–Vis, FT-IR, AFM and electrochemical studies. The FT-IR spectral studies indicated the presence of metal oxide and polymer in Nano composites. From the FT-IR spectra of Nano composites, the peak around 464 cm−1 indicated the bonding between Zn and O, the peak around 1573 cm−1 and 1503 cm−1 due to stretching vibrations of the quinonoid and benzenoid rings of polyaniline respectively. The surface morphology was characterized by AFM. The UV–Vis spectrum of polyaniline was observed five absorption bands around 230 nm, 258 nm, 299 nm, 457 nm and 632 nm. Among these five bands, the absorption band around 299 nm is assigned to the π–π* transition of the phenyl ring and another band at 632 nm is assigned to the polaron n–π* transition. The UV–vis spectral absorption intensity of Nano composites was increased as increasing of zinc oxide incorporation in polyaniline. Cyclic Voltammetric studies exhibit good sensitivity response at pH 1.0. Chronoamperometric and Chronocoulometric studies were also carried out for polymer–metal oxide nanocomposites. The present study especially aims to investigate PAni-ZnO Nano composites in order to obtain a new noble material which can be utilized for solar cell applications.

Recently in nanophotonics, a rigorous evolution from passive to active metasurfaces has been witnessed. This advancement not only brings forward interesting physical phenomena but also elicits opportunities for practical applications. However, active metasurfaces operating at visible frequencies often exhibit low performance due to design and fabrication restrictions at the nanoscale. In this work, we demonstrate electrochemically controlled metasurfaces with high intensity contrast, fast switching rate, and excellent reversibility at visible frequencies. We use a conducting polymer, polyaniline (PANI), that can be locally conjugated on preselected gold nanorods to actively control the phase profiles of the metasurfaces. The optical responses of the metasurfaces can be in situ monitored and optimized by controlling the PANI growth of subwavelength dimension during the electrochemical process. We showcase electrochemically controlled anomalous transmission and holography with good switching performance. Such electrochemically powered optical metasurfaces lay a solid basis to develop metasurface devices for real-world optical applications.

In this study, an efficient strategy is used to prepare perovskite photoactive layer with superb optoelectronic merits by utilizing polyaniline polymer as an efficient additive to improve perovskite quality. As a result, we prove that the small content of polyaniline (PANI) provides not only suppresses the perovskite defects and lead iodide but also produces a passivation impact. By regarding using macromolecular phases with long chain polymers, the generation of a PANI-perovskite cross-linking is possible. The cross-linking acts to bridge the perovskite crystals, mitigating carrier trapping by grain boundaries and achieving remarkable air stability against humid, which has not been obtainable with tiny molecules defect passivating materials. Also, PANI promoted the development of Lewis base adduct with the perovskite precursor, which, maximized the activation energy for nucleation and growth of the perovskite phase. Therefore, the perovskite layer with optimized PANI additive showed higher crystallinity in (110) crystal plane. After PANI addition, the perovskite grains found to be enlarged from 350 nm to 620 nm. Also, the PSCs with PANI showed suppressed luminescence effect, which indicates lower recombination rates. The SCLC measurements revealed that the PANI additive improving the interfacial contact between the ZnO and perovskite due to reduction the trapped density from 1.78 × 1016 cm-3 to 2.46 × 1015. Consequently, the champion cell yields an efficiency of 17.39% for 4% polyaniline doped electron transport material with negligible hysteresis. This reduces PSC instability generating a device that retained 93% of its original performance after 600 h maintaining in air conditions without any encapsulation.

In the present work, PANI/ Mg x Co 1 − x Fe 2 O 4 (x = 0.2, 0.4, 0.6, 0.8) nanocomposites were synthesized via in-situ oxidation polymerization. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed the formation of nanocomposites. Morphological study of synthesized materials was carried out by scanning electron microscope (SEM) analysis which confirms the construction of magnetic conducting phases in composite materials.Thermogravimetric analysis (TGA) of composites revealed that the thermal stability of the composite with large concentration of magnesium is superior due to higher interaction between the polymer and ferrite nanoparticles. The calculated activation energy of the materials from DC conductivity measurement was found to be considerable sensitive with the varying amount of magnesium contents in the synthesized materials. Dielectric measurements (e' and e'') and AC conductivity ( σ ac ) of samples were studied through impedance analyzer in the frequency range of 100 Hz to 10 MHz. The different investigated properties of fabricated materials are presenting them as promising materials for various high frequency applications.

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs. In this work, water-soluble polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way, leaving no evidence of membrane poration/disturbance or cell death, thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents. For aqueous synthesis, which is important for biocompatibility, the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme. Owing to its fluorescent properties, the localization of as-prepared PANI:PSS is determined by the confocal microscope, and the results confirm its rapid entry into bacteria. Under 808 nm near-infrared (NIR) irradiation, the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects. Staphylococcus aureus (S. aureus), Methicillin-resistantStaphylococcus aureus (MRSA) and Escherichia coli (E. coli) could be effectively eliminated as well as the corresponding bacterial biofilms. Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects. Therefore, the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections., Graphical abstract Image 1, Highlights • Water-soluble, amphiphilic PANI:PSS can penetrate the membrane without overt membrane disruption/poration. • PANI:PSS is superior to traditional cationic antibacterial agents. • PANI:PSS can generate local hyperthermia from inside the bacteria. • PANI:PSS can eliminate bacteria as well as their biofilms.

The metal ions or conductive macromolecules intercalated hydrated vanadium oxides for aqueous Zn-ion batteries (AZIBs) have received increasing attention in recent years. The strategy for the preparation of the intercalated hydrated vanadium oxides has been achieved great advances but is still a huge challenge. In this contribution, we develop an interface-intercalation method to synthesize the polyaniline-intercalated hydrated vanadium pentoxide (V2O5·nH2O), denoted as PANI-VOH, as the cathode materials for AZIBs. The prepared PANI-VOH exhibits a 3D sponge-like morphology and the surface area of 190 m2·g−1. The interlayer spacing of VOH is expanded to be 14.1 A, which provides a lot of channels for the rapidly reversible (de)intercalation of Zn2+ ions. The coin-typed Zn//PANI-VOH battery shows the specific discharge capacity of 363 mAh·g−1 at 0.1 A·g−1 and stable cycling performance. Furthermore, the specific capacity remains 131 mAh·g−1 after 2000 cycles at 5 A·g−1, and the energy density is calculated to be 275 Wh·kg−1 at 78 W·kg−1 on the mass of PANI-VOH. The achieved values are comparable to or even much higher than that of the most state-of-the-art V-based cathode materials for AZIBs. The PANI intercalation can shorten the pathways and facilitate the transports for the migration of ions and electrons. Our finding guides a novel strategy for the intercalation of PANI into the layered materials to adjust their interlayer spacing, which exhibits super ions migration efficiency, as the cathode materials for AZIBs and even other multivalent ions batteries.

In this work, lignin-based carbon nanofibers (LCNFs) were for the first time served as substrate for in-situ electrodeposition of polyaniline (PANI) and tested as pseudocapacitor. Two LCNFs with different lignin ratios were designed to distinguish their morphology and structural properties. Next, PANI deposition mechanisms on both LCNFs were investigated and the electrochemical performance of the resulting LCNF/PANIs were evaluated. It was found although LCNF2 was composed of less uniform nanofibers due to more presence of lignin in precursor dope, it had higher tensile strength/modulus than LCNF1 (strength: 34.3MPa to 24.2 MPa; Modulus: 2.40 GPa to 1.45GPa) and was more cost-effective. Particularly, the beaded fibers on LCNF2 contributes to the deposition of PANI with higher specific mass capacitance (612.8 F g−1 to 547.0 F g−1). Upon assembling into solid-state supercapacitors, the Cm of LCNF2/PANI device was determined to be 229 F g−1 and the maximum energy density was 11.13Wh kg−1 at a power density of 0.08 kW kg−1. This work showed LCNF produced from renewable and low-cost lignin could be directly used as substrate for PANI deposition. Moreover, the composition in spinning dope played an important role in determining the performances of resulting pseudocapacitors.

The present study deals with the synthesis, characterization, and testing of a novel composite, zirconium(IV) phosphate-coated polyaniline (ZrPO4@PANI), toward the adsorption- and surface-controlled toxicity applications. Following the synthesis of the ZrPO4@PANI composite using the sol–gel route, various characterization techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, and powder X-ray diffraction were employed to confirm its surface functionality, morphology and agglomeration, and crystallinity and crystal nature, respectively. The composite was found to be effective toward the adsorptive removal of the methylene blue dye (an organic pollutant) as against the changes in the dye concentration, dose, pH, and so forth. Also, to understand the MB adsorption kinetics, the experimental data were evaluated using the Langmuir and Freundlich models and the results were described in accordance with the Langmuir isotherm model (an adsorption capacity of 120.48 mg/g at ambient temperature). In addition, the tests conducted using pseudo-first- and pseudo-second-order kinetic models confirmed the existence of pseudo-second-order rates. Furthermore, the calculation of thermodynamic parameters for the MB adsorption, namely, changes in enthalpy, entropy, and Gibbs’ free energy, exhibited a spontaneous, feasible, and exothermic nature. Finally, the comparative studies of in vitro toxicity and flow cytometry confirmed that the copresence of ZrPO4 along with PANI significantly improved the biocompatibility. The outcome of the experimental results implies that the composite is capable enough of serving as the safe and low-cost adsorbent, in addition to supporting the effective capping of the surface toxicity of PANI.

A composite consisting of Reduced Graphene Oxide (RGO), Tin Oxide (SnO2) nanoparticles and Polyaniline (PANI) conducting polymer was studied as a potential counter electrode material for Dye Sensitized Solar Cells (DSSCs). This RGO/SnO2/PANI composite CE was fabricated by spray method and used as an alternative to Platinum (Pt) counter electrode (CE). In the fabrication of RGO/SnO2/PANI composite CEs, several optimizations were carried out to obtain the optimum RGO sintering temperature and the optimum amounts of RGO, SnO2 and PANI. The photovoltaic performance of the DSSCs based on the newly prepared CEs was studied by using I-V measurements. The efficiency of the DSSC with the CE with optimized RGO/SnO2/PANI composition having 9.8 μm thickness was 7.92% under the 100 mW cm−2 (1.5AM) light illumination. After the TiCl4 treated TiO2 photoanode was used, the maximum power conversion efficiency of the DSSC based on the RGO/SnO2/PANI composite CE was increased to 8.68%, which corresponds to an impressive 94% of the efficiency of 9.22% obtained for the control DSSC made with Pt CE and TiCl4 treated photoanode measured under same light illumination. These composite CEs were characterized by X-ray diffraction, Raman spectra, FTIR spectra, SEM and TEM. Cyclic voltammetry (CV) analysis showed the excellent electro-catalytic activity of the composite CE. With high energy conversion efficiency and improved charge-transfer process of DSSCs in combination with simple preparation and relatively low-cost technique, the RGO/SnO2/PANI composite electrode demonstrates the beneficial use of this novel composite material as CEs in DSSCs.

Solid polymer electrolytes have been broadly studied due to their wide applications in various electrochemical devices. In the present work, the electrical properties of polyaniline and its composites with BaSO4 have been studied. The polymerization of aniline monomer via the ordinary chemical polymerization process showed an amorphous structure. Whereas, in the presence of BaSO4 as a seed, the aniline is polymerized in an orthorhombic crystalline structure on the BaSO4-surface. Two composite samples of PANI and BaSO4 with different amounts of BaSO4 (1.5 and 2.5 wt%) were prepared and analyzed using XRD, FT-IR, SEM, and XPS techniques. The ac- electrical studies on the composites showed an enhancement in the electrical conductivity of PANI due to the addition of BaSO4. Ac- conductivity at frequency 500 kHz, and 100 °C, showed values of 1.9 × 10−3, 5.4 × 10−4, 1.6 × 10−1, and 1.9 × 10−1 S/cm for PANI, BaSO4, BaSO4/PANI 1.5 wt%, and BaSO4/PANI 2.5 wt%, respectively.