Electrodeposition Of Polyaniline Research Articles

Investigation of polyaniline electrodeposition on hydrophilic/hydrophobic carbon cloth substrates for symmetric coin cell supercapacitors

Investigation of polyaniline electrodeposition on hydrophilic/hydrophobic carbon cloth substrates for symmetric coin cell supercapacitors

Maintaining Electrochemical Performance of Flexible ITO-PET Electrodes under High Strain.

Flexible electrode materials, particularly indium tin oxide (ITO)-coated polyethylene terephthalate (PET), have attracted the attention of researchers for a wide variety of applications. However, there has been limited attention to the effects of electrode flexibility during electrochemical processes. In this research article, we studied how bending commercially available ITO-PET electrodes impacts the electrodeposition process of polyaniline (PANI). Thicker ITO layers start cracking at a normalized strain of 0.10 (bending radius of 10 mm), and cracking becomes detrimental to full deposition at a normalized strain of 0.16 or higher (bending radius of 6 mm or lower). Thinner ITO layers were evaluated as electrodes in electrochemical applications; however, the higher resistance of these electrodes prevented uniform electrodeposition of PANI. In order to overcome the issues of cracking, conductive thin films and copper tape were explored as low-cost methods for electrically bridging cracks in the electrode. While conductive thin films reduced the resistance effect, copper tape was found to fully restore the original electrochemical activity as measured by chronoamperometry and enable uniform electrodeposition at a bending radius as low as 3 mm. This strategy was then demonstrated by performing electrochromic bleaching of PANI under high-strain conditions. These studies illustrate some of the limitations of ITO-PET electrodes and strategies for overcoming these limitations for future applications that require a high degree of flexibility in a transparent electrode substrate.

Electrodeposition of polyaniline on reduced graphene oxide/cotton yarn with tunable electrochemical performance for flexible textile supercapacitors

Graphene/cotton fibers show significant promise in wearable energy storage due to their low cost, porous structure, and exceptional integration ability into wearable systems. However, the eco-unfriendly reductants and standalone electric double-layer capacitor hindered their application. Herein, a green and rapid hydrothermal-electrodeposition method was proposed to fabricate polyaniline (PANI) decorated reduced graphene oxide (rGO)/cotton yarns without using any chemical reductants and oxidants. The PANI/rGO/cotton (PRC) yarn exhibited porous conductive network, structural controllability, and mechanical flexibility. Additionally, the PRC yarn electrode delivers a fast electron transport and ion migration, synergistic energy storage contribution, and a controllable capacitance (up to 81.2 mF cm−1 at 0.2 mA cm−1). The assembled yarn supercapacitor shows a good capacitance (19.8 mF cm−1 at 0.08 mA cm−1), excellent energy-power density (2.7 μWh cm−1 at 40 μW cm−1), and great capacitance retention. This green fabrication of PRC yarns brings new insights into the development of wearable energy storage.

A LAMP-based hydrogen ion selective electrochemical sensor for highly sensitive detection of Mycoplasma pneumoniae.

A concise and rapid detection method for Mycoplasma pneumoniae is urgently required due to its severe impact on human health. To meet such a need, this study proposed and constructed an innovative point-of-care testing (POCT) platform that consists of a hydrogen ion-selective loop-mediated isothermal amplification (H+-LAMP) sensor and an electrochemical detection device. The H+-LAMP sensor successfully integrated the working and reference electrodes and converted the H+ generated during the LAMP process into an electrochemical signal. High sensitivity and stability for pathogen detection were also achieved by treating the working electrode with an electrodeposited polyaniline solid contact layer and by using an ion-selective membrane. As a result, the sensor shows a sensitivity of 68.26 mV per pH, a response time of less than 2 s, and a potential drift of less than 5 mV within one hour, which well meets the urgent need. The results also demonstrated that the detection limit for Mycoplasma pneumoniae was lowered to 1 copy per μL, the nucleic acid extraction and detection process could be completed in 30 minutes, and the impact of interfering ions on the sensor was negligible. Validation with 20 clinical samples yielded satisfactory results. More importantly, the storage lifespan of such an electrochemical sensor is over seven days, which is a great advantage for on-site pathogen detection. Therefore, the hydrogen ion-selective sensor constructed in this investigation is particularly suitable as a core component for instant pathogen detection platforms.

Highly-efficient uranium reduction, organic oxidation and electricity generation via a solar-driven wastewater resourceization system with a PANI/CF cathode

Co-existed organics bring great challenges for uranium recycling from water because of the formation of obstinate complexes with uranyl ions (UO22+), predominated species of uranium in water). Here, we proposed an effective strategy to simultaneously decompose organics and recycle uranium from complex radioactive wastewater, combined with electricity production, by a solar-driven wastewater resourcization system (SWRS), in which an electrodeposited polyaniline (PANI) decorated carbon fiber (CF-PANI) cathode was used for highly efficient UO22+ reduction based on the abundant –NH- groups and conductivity of PANI. Under sunlight illumination, a BiVO4 decorated WO3 nanoplate array (BVO/WNP) combined with a rear silicon cell (SC) was applied as the monolithic photoanode to generate oxidative holes and derived hydroxyl radicals for robust organic oxidation, and driven electrons to the CF-PANI cathode for uranium reduction and simultaneous electricity generation at external circuit. Compared to CF, the optimized CF-PANI improved the rate constants (k) by 6 and 6.7 times for UO22+ and organic removal, respectively, and enhanced power output by 2 times (Pmax, 1.12 mW/cm2). Additionally, near 100 % removal ratios for both UO22+ and organics accompanying with Pmax around 1 mW/cm2 were achieved by SWRS when treating model complex wastewater under wide conditions or even under real sunlight illumination. The fixed uranium on the CF-PANI cathode was mainly reduced into U(IV) species (95.8 %) and the repeated tests demonstrated the excellent stability of SWRS (without obvious decay after reusing 15 times). This work provides new insights on the resourceful treatment of radioactive wastewater and contaminated waters.

(Digital Presentation) Construction of a Novel Phosphate Potential Sensor and Its Application

Phosphorus content is one of important indicators in the evaluation of water quality. The level of phosphorus in oilfield water systems not only affects the overall water cycle production system, but excessive phosphorus wastewater entering the environment can cause eutrophication of the water body, as can high levels of ammonia and nitrogen, and leading to rapid growth of algae and thus affecting the balance of the aquatic ecosystem. Therefore, the regulation of phosphorus is of great importance. Phosphorus exists in nature mainly in the form of phosphate, which is currently detected by the traditional spectrophotometric method. As this method requires the addition of a large number of chemical reagents, it is not only complex and time consuming, but also produces a waste solution at the end of the test that can easily cause secondary pollution to the environment. Compared to traditional methods, Ion Selective Electrodes (ISEs) are easier to use, more sensitive, less expensive and do not cause secondary contamination. In conventional ion selective electrode detection systems, liquid contact ion selective electrodes consisting of a polymeric ion selective membrane, an internal filling fluid and an internal reference electrode are susceptible to common variables such as pressure and temperature. There are problems with complex maintenance, leakage and signal calibration. In contrast, all-solid ion-selective electrodes that eliminate the internal filling fluid and internal reference have become a hot research topic for such potential-based sensors. In this thesis, the following research was carried out with the aim of developing a phosphate potentiometric sensor with practical detection capabilities:(1) PANI/ITO electrodes were produced by electrodeposition of polyaniline on ITO conductive glass by constant potential deposition and by ultrasonic peeling. Three oxidation states of PANI/ITO electrodes were prepared at different voltages using phosphoric acid as the doping solution. LBPANI/ITO electrode in the fully reduced state, ESPANI/ITO electrode in the semi-oxidized state and PBPANI/ITO electrode in the fully oxidized state. The response sensitivity and stability of the three electrodes were investigated to determine the optimum doping potential; the response performance of the electrodes was tested for different doping times to determine the optimum preparation time. It is shown that the PBPANI/ITO electrode in the fully oxidized state has the optimum stability and response sensitivity at a doping time of 80 s. The electrode showed good linear response in the range of 1.00x10-5 ~ 1.00x10-1 M, with a response sensitivity of 37.30 dec/mV (R2 = 0.9966) and a detection limit of 10-5.6 M. The response time of the electrode to the solution was around 4 s, and it had good acid-base adaptability (pH 4.0 ~ 8.0). The performance of the prepared PBPANI/ITO electrode as a potentiometric phosphate sensor was also investigated in terms of stability (n = 10, RSD 1.76 %) and lifetime (6 weeks at room temperature), and was successfully used for phosphate detection and analysis in oilfield re-injection water, lake water and tap water samples in real environments with satisfactory results. (2) To further prepare a phosphate potential sensor with a high sensitivity response. We pretreated the home-made cobalt electrode with high pressure anodic oxidation in sodium hydroxide solution to produce a uniform cobalt oxide passivation film on the electrode surface. The sensitivity and stability of the response of the electrode at different pretreatment times were investigated to determine the optimum preparation conditions. The results showed that the pretreated cobalt electrode had a good response in the range of 1.00x10-5 ~ 1.00x10-1 M. The response sensitivity was 67.22 mV dec, R2 = 0.9939 and the detection limit was 10-5.5 M. It was much higher than that of the untreated cobalt electrode. This far exceeded that of the untreated polished cobalt electrode (36 ~ 40 mV/dec). The performance of the pretreated cobalt electrode as a potentiometric phosphate sensor was also investigated in terms of lifetime (7 weeks at room temperature), response rate (less 40 s), stability (n = 10, RSD 1.07 %) and acid-base adaptability (pH 4.0 ~ 8.0), and the sensor was successfully used for phosphate in oilfield re-injection water, lake water and tap water samples with satisfactory results.

Electrodeposition of Polyaniline on Tantalum: Redox Behavior, Morphology and Capacitive Properties

Polyaniline (PANI) is among the most widely studied conducting polymers due to its potential technological applications in various fields. Recently, PANI-based hybrid materials have played an important role in the development of energy storage and conversion systems. The aim of the present work is the investigation of the simultaneous electrochemical growth of PANI and Ta2O5 on the Ta substrate and the characterization of the morphology, redox behavior and pseudocapacitive properties of the resulting micro- or nanostructured composite thin films. A well-adherent conductive Ta2O5-PANI composite film was first formed using cyclic voltammetry on Ta that facilitates the on-top electrodeposition of single PANI via an autocatalytic mechanism. The electrochemical characterization of the Ta|Ta2O5-PANI|PANI electrodes reveals unique redox properties of PANI not shown previously upon using PANI electrodeposition on Ta. Scanning electron microscopy shows that the morphology of the electrodeposited films comprises nano- or microspheres that may develop into nano- or microrods when the polymerization proceeds. Preliminary evaluation of the capacitive properties of the Ta|Ta2O5-PANI|PANI electrode shows adequately high specific capacitance values as high as 1130 F g−1 (at 9.2 mA cm−2), depending on the electrochemical parameters, as well as adequate stability (~80% retention after 100 cycles), indicating their potential application as energy storage devices.

Layer interfacing strategy to derive free standing CoFe@PANI bifunctional electrocatalyst towards oxygen evolution reaction and methanol oxidation reaction

Developing inexpensive, highly electrochemically active, and stable catalysts towards electrochemical studies remains challenge for researchers. In this regard, binder-free CoFe@PANI composite electrocatalyst is deposited on nickel foam (NF) substrate via successive electrodeposition of polyaniline (PANI) and CoFe-LDH at Room temperature (RT). As deposited binder-free CoFe@PANI electrocatalyst displays high electrocatalytic activity towards oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) in alkaline media. In CoFe@PANI structure, interfacing of high-electron conducting PANI establishes strong interconnection with CoFe-LDH by tuning electronic structures, which accelerates the electrochemical performance towards OER and MOR. For OER, CoFe@PANI requires low overpotential (η10) of 237 mV to reach current density (Id) of 10 mA cm−2 and displays low Tafel slope value of 46 mV dec−1 in 1 M KOH solution. Also, it displayed specific Id of 120 mA cm−2, when it was tested for MOR in 1 M KOH with 0.5 M methanol solution. The superior electrocatalytic activity of CoFe@PANI is mainly ascribed to high electrochemical active surface area (ECSA), abundant active sites and fast electron transfer between electrocatalyst and electrode surface. Of note, the current work may open new era for design and development of non-precious highly active and stable hybrid electrocatalysts at RT for various applications.

Highly Stable CuS Nanotrough‐Networks Constructed on Arbitrate Substrate for Flexible Supercapacitor

Herein, supercapacitors (SC) are fabricated on arbitrary flexible substrates by constructing copper sulfide nanotrough‐network and electrodeposition of polyaniline (PANI@CuS NN) as electrode. Attributed to its unique hollow structure, the CuS NN current collector demonstrates high conductivity (10.4 Ω □−1) and mechanical flexibility (within 2.3% relative resistance change after more than 1,000 bending times at the radius of 4 mm). The obtained PANI@CuS NN electrode demonstrates more than 218.28 F g−1 specific capacity at the current density of 1 A g−1, remaining 85.08% of the original capacity after 1,000 cycles (5 A g−1). This can be attributed to that CuS NN provides abundant attachment sites for PANI by the large specific surface area. Additionally, a flexible solid‐state supercapacitor is constructed by coating silk fibroin hydrogel as the electrolyte between the PANI@CuS NN and another CuS NN electrode loaded with multiwalled carbon nanotubes (MWCNTs@CuS NN). The capacity is 107.8 F g−1 at the current density of 0.25 A g−1 with excellent cycling stability.

Enhanced electrochemical properties of polyaniline (PANI) films electrodeposited on carbon fiber felt (CFF): Influence of monomer/acid ratio and deposition time parameters in energy storage applications

The growing demand for materials with high charge storage capacity, power, and energy density, and a long-life cycle became devices developed for the high power delivery require as supercapacitors the subject of intense research. Conductive polymers are a class of materials widely used in the development of supercapacitors. In particular, PANI is a promising polymer in electrode development due to its high specific capacitance, conductivity, flexibility, thermal stability, and low cost. Carbon felt fiber (CFF) is frequently used as a conductive substrate in the development of composites due to its physicochemical stability, good cost-benefit, and easy obtainability, being an excellent material for the preparation of devices of different shapes. In this work, composite electrodes were prepared by electrodeposition of PANI on CFF substrate according to a systematic study involving two different heat treatments, four synthesis times, and two molar proportions with the aid of the Kruskal-Wallis test to validate the importance of the variables concerning the specific capacitance and the mass of PANI deposited. The samples were characterized by physical-chemical instrumental techniques, for characterization of the local and crystalline structure, in addition to morphological analysis. Finally, the composites were evaluated using electrochemical techniques to analyze their performance in supercapacitor devices. Based on the analyzed data, it was found that all parameters are relevant for the optimization of the system in the preparation of materials with greater load storage capacity. Thus, among all the conditions, the specific capacitance that stands out the most is that obtained by the sample CFF 2000 2:1 1350s reaching the value of 303.76 F. g−1.

RBD-Modified Polyaniline-Based Label-Free Immunosensor for Sensitive Impedimetric Detection of Anti-SARS-CoV-2 Antibodies

The emergence of the SARS-CoV-2 virus and the associated pandemic has affected the entire human population. Human susceptibility to the virus has highlighted a tremendous need for affordable diagnostic systems to manage the pandemic and monitor the effectiveness of vaccination. We have developed a simple and label-free electrochemical immunosensor for the detection of human anti-SARS-CoV-2 IgG antibodies, which consists of a supporting screen-printed carbon electrode (SPCE) modified with an electrodeposited polyaniline film and glutaraldehyde, allowing effective immobilization of the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) as a biorecognition element. The impedimetric immunosensor showed a linear response over a wide concentration range of 0.01–10 μg mL−1, that is, 67 pM–6.7 nM, with a low detection limit of 25.9 pM. A dual working electrode configuration with a built-in negative control unit was demonstrated for practical field applications. The immunosensor was successfully used in a real serum sample from an infected patient and showed good reproducibility and fair agreement with ELISA. An optional amplification step with secondary goat anti-human IgG antibodies was demonstrated, resulting in an extended linear range and a detection limit as low as 0.93 pM.

Insight into the corrosion inhibition of the iron anode with electro-deposited polyaniline during the electrocoagulation treatment process of electroplating wastewater

In this study, polyaniline (PANI) and polypyrrole (PPy) coatings were applied to modify iron plate anodes to treat electroplating wastewater by electrocoagulation (EC) treatment.

Polyaniline decorated salt activated phenolic resin/PAN-based carbon nanofibers with remarkable cycle stability for energy storage applications

Polyaniline (PANI) decorated salt-activated phenolic resin (PR)/polyacrylonitrile (PAN)-based carbon nanofibers (PANI/CNFs) were fabricated by the consecutive solution electrospinning, salt activation and PANI electrodeposition methods for supercapacitor applications. The electrochemical energy storage properties of the PANI-decorated activated PANI/CNFs (activated PAN: CNF-A, activated PR/PAN28 (weight ratio of PR and PAN is 2:8): CNF28-A) were evaluated by assembling the electrodes into a symmetric supercapacitor (SSC) device. The specific capacitance of the device was ca. 336F g−1 at the current density of 1 A/g. The device possessed an energy density of 13.33 Wh kg−1 at a power density of 200 W kg−1 with a retention life of nearly 100 % after 5,000 cycles.

Ambipolar All-Organic Solid-State Electrochromic Device Using Electrodeposited Polyaniline: Improving Performance by Design

Ambipolar All-Organic Solid-State Electrochromic Device Using Electrodeposited Polyaniline: Improving Performance by Design

Electrodeposition of polyaniline on high electroactive indium tin oxide nanoparticles-modified fluorine doped tin oxide electrode for fabrication of high-performance hybrid supercapacitor

In this study, hierarchical polyaniline (PANI) nanosheets were electrochemically deposited on indium tin oxide nanoparticles coated fluorine-doped tin oxide glass (ITONPs-FTO) substrate from an aqueous solution containing 0.5 M aniline and 1 M H2SO4. The ITONPs provide efficient support with high electroactive surface area in the electrochemical deposition of PANI and produce excellent PANI films. The developed PANI film deposited on the ITONPs-FTO electrode was characterized via field-emission scanning-electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. A hybrid supercapacitor (HSC) was fabricated using the developed PANI deposited ITONPs-FTO as a positrode and the jute sticks derived activated carbon nanosheets coated FTO (JAC-FTO) as a negatrode. Because of its high capacitive performance, unique structures of electrode materials, and optimum operating potential window, the fabricated PANI-ITONPs-FTO//JAC-FTO HSC performed excellently in 0.1 M HCl aqueous electrolyte, delivering a high areal capacitance of 318 mF/cm2 at a 1.0 mA/cm2 current density and exhibit a high energy density of 28 µWh/cm2 at a high power density of 400 µW/cm2. Moreover, the HSC exhibits excellent cyclic stability with ∼ 87% Coulombic efficiency and ∼ 91% capacitance retention after 1000 charge–discharge cycles.

Nucleation, Growth and Electrochemical Performances of Polyaniline Electrodeposited on ITO Substrate

In the first part of the present work, we determined for the first time the electrodeposition mechanism of a polyaniline film on the ITO (Indium tin oxide) substrate in an acidic medium (HNO3 1 M ) using chronoamperometry. The analysis of the ascending parts and maxima of the current density-time transients and the images obtained by the SEM technique, allowed us to deduce that the polyaniline electrodeposition follows the mechanism of progressive 3D nucleation and growth. In the second part, we have studied, by cyclic voltammetry and galvanostatic charge-discharge, the effect of electropolymerization potential (0.8, 0.9, 1.0, 1.1 and 1.2 V) on the specific capacitance of the films. Cyclic voltammetry shows that the specific capacitance increases from 4.28 mF cm−2 (deposition potential 0.8 V/SCE) to 43.12 mF cm−2 (potential 1.2 V/SCE) for a scan rate of 5 mV/s. The specific capacitance decreases sharply with the scan rate for the deposition potentials 1.0, 1.1 and 1.2 V/SCE, whereas it remains almost constant for the films obtained at 0.8 and 0.9 V/SCE. A similar behaviour was obtained by galvanostatic charge-discharge: the specific capacitance increases from 4.14mF cm−2 (0.8 V/SCE) to 60.60 mF cm−2 (1.2 V/SCE) for the discharge current density 0.1 mA cm−2.

Laser‐Scribed Graphene–Polyaniline Microsupercapacitor for Internet‐of‐Things Applications

AbstractThe push toward smart technologies and the Internet‐of‐Things (IoT) demands the development of miniaturized energy storage devices. Herein, a facile and scalable strategy is presented, based on laser reduction of graphene oxide into graphene followed by electrodeposition of polyaniline (PANi), to fabricate a substrate‐free supercapacitor. The fabricated supercapacitor is part of a flexible multifunctional integrated system comprising a thin‐film humidity sensor, a resistor, and a near field communication (NFC) antenna for IoT‐linked wireless communication with a smartphone. The integrated sensory system shares laser‐scribed graphene (LSG) as the same electrode material for all the components (supercapacitor, sensor, resistor, and NFC antenna). The symmetric LSG‐PANi||LSG‐PANi supercapacitor with wireless charging capability exhibits a near record‐high energy density of 0.407 mW h cm−3, and excellent power density of 196 mW cm−3, along with an outstanding rate capability (enduring high rates of over 1 V s−1). As a humidity sensor, the device demonstrates high resistance changes from 2000 kΩ at 0% relative humidity (RH) to 497 kΩ at 100% RH (15 kΩ per RH%) with a sub‐second scale (0.87 s) response time. This research paves the way for limitless applications of IoT across a wide spectrum of fields from healthcare to chip‐based electronics to environmental monitoring.

Latent Fingerprint Enhancement on Metallic Surfaces Using Electroactive Film Deposition Combined with Electrochemically Driven Dye Encapsulation

Criminal investigations require establishment of the identities of suspects, victims and witnesses. The most common physical evidence that accomplishes this is a fingermark: it is unique to an individual and time-invariant. Its presence can establish contact between an individual and an object or place the individual at a crime scene. In practice, most such marks are latent (non-visible) fingermarks: these require chemical or physical treatment to render a visible image. Typical chemical treatments involve interaction of a reagent (powder, cyanoacrylate, dye) with the fingerprint residue. Deterioration or loss of residue due to environmental exposure limits the efficacy of these treatments. The success rate for developing a latent mark to a standard permitting a legally acceptable identification is only ca. 10%; this motivates new chemical approaches.In a complementary strategy, we have used the fingerprint residue as a template (“mask”) to direct electrochemically generated reagent to the bare surface between the deposited ridges, thereby creating a negative image of the fingerprint. On metallic substrates the deposition and viewing processes may be controlled electrochemically. This offers the promise of application to a range of objects forensically relevant to both violent crime (knives, guns, bullet casings) and volume crime (tools, handles at points of entry and metal theft). This templating concept was originally demonstrated using electrodeposited polyaniline [1] and PEDOT [2] films, whose electrochromic properties were used to optimize the visual contrast within the fingerprint image. We subsequently extended this concept through the use of electrodeposited poly(pyrrole-co-3,4-ethylenedioxythiophene) copolymers of varying composition to provide wider and more subtle variation of optical properties (simplistically, colour) [3]. Through deliberate selection of co-monomer feedstock, polymer deposition potential and subsequent “viewing” potential, one could then pre-select bespoke material characteristics optimized to a specific substrate.Here we further extend the concept by the inclusion of the dyes Methyl Red (MR), Methyl Orange (MO), Indigo Carmine (IC) or Basic Yellow 40 (BY) into electrodeposited polypyrrole (PPy) films by a combination of electrostatic and/or physical entrapment. The substrates were stainless steel electrodes, upon which a latent fingerprint had been deposited. The deposition medium was an aqueous pyrrole (0.05 mol L-1) / dye (0.005 mol L-1) solution. In the case of MR, sodium dodecylsulphate (0.005 mol L-1) was employed to improve dye solubility. We compare the effectiveness of potentiostatic (0.90 – 1.00 V vs. Ag/AgCl) and galvanostatic (2.5 – 5.0 mA cm-2) deposition control functions. The extent of polymer deposition was varied via deposition time (60 to 300 s) and coulometrically assayed.Dye encapsulation was qualitatively apparent as the polypyrrole films presented the colour of the dye used as dopant: PPy/MR and PPy/MO films were reddish-brown, and PPy/IC was blue. Complementary to these colours seen via absorbance, the emission properties of BY (widely used in conjunction with cyanoacrylate) are also apparent via fluorescence when irradiated with UV light. We will present and interpret images demonstrating how these all these composite electroactive materials yield excellent colour contrast between the surface and the fingerprint. Specifically, one can readily identify the so-called second level features that, in conjunction with dactyloscopy images, unambiguously identify individuals or establish connections between crime scenes. The advantages of this approach, alone and in combination with conventional visualization techniques, will be discussed.

High Capacitive Antimonene/CNT/PANI Free‐Standing Electrodes for Flexible Supercapacitor Engaged with Self‐Healing Function

In virtue of the high electrochemical activity and inherent flexibility, polyaniline (PANI) is an ideal electrode material for flexible supercapacitors (SCs). However, in practical applications, the inevitable agglomeration of PANI leads to low capacitance, poor rate performance, and cycling stability. Here, antimonene (Sb) nanosheets with ultrathin thickness, excellent mechanical strength, and flexibility are introduced into the carbon nanotube (CNT) framework for PANI electrodeposition via simple vacuum filtration, which enables the continuous and uniform growth of PANI. The resultant free-standing Sb/CNT/PANI electrode can thus exhibit a high specific capacitance of 578.57Fg-1 together with a high rate capability. Besides, thanks to the introduction of Sb nanosheets, the agglomeration of PANI during the electrodeposition is improved, which correspondingly alleviates the structural deterioration of PANI during repeated charge/discharge. Thus, the flexible SC assembled by Sb/CNT/PANI electrodes demonstrates both an impressive specific capacitance of 416Fg-1 and outstanding cycling stability over 12000 cycles. Moreover, this SC device can have a practical self-healing function by employing self-healable polyurethane. The facile strategy reported herein sheds light on the design of high-performance flexible SCs, catering to the needs of portable and wearable electronics.

The Performance of Polyaniline Electropolymerization at Various Acidic Electrolytes on Gold Electrodes for Electrochemical Biosensor Application

Polyaniline (PANI), a conductive polymer, has been played a significant role as an electrode material for electrochemical biosensor development. In this study, the electrochemical properties of PANI synthesized in two different acid dopants, i.e. 1.0 M HCl and 0.50 M H2SO4using chronopotentiometry, were investigated. The surface morphologies of the PANI modified gold electrodes were observed using SEM and EDS. The PANI electrodeposition times were also considered. The electrochemical characteristics in terms of the peak-to-peak potential separations (ΔEp), the current of the oxidation (Ipa), and reversible redox properties were investigated using cyclic voltammetry. The results showed that the modified electrode with PANI electropolymerization in H2SO4 as a dopant performed significantly better electrochemically than PANI in HCl at all electrodeposition times. In particular, the PANI prepared in H2SO4 with the electrodeposition time of 120 s demonstrated the best performance in terms of electron transfer and reversible redox reaction.