Graphene Oxide Polyaniline Research Articles

Water-dispersible polyaniline/graphene oxide counter electrodes for dye-sensitized solar cells: Influence of synthesis route on the device performance

The fabrication of efficient and platinum-free counter electrodes (CE) is a highlighted topic for the development of advanced dye-sensitized solar cells (DSSCs). Here, we developed water-dispersible polyaniline/graphene oxide (PANI-GO)-based CEs, which can be straightforwardly prepared by deposition of the nanocomposite dispersion onto FTO substrate. The water-dispersibility properties of PANI-GO allow the formation of smooth films without organic solvents making it a promising material for high-scalable, reduced cost and ‘greener’ fabrication of energy conversion-storage devices. Aqueous dispersions of PANI-GO nanocomposites were prepared by two different routes: physical mixture of PANI and GO, and in situ polymerization of aniline in GO aqueous dispersion. DSSC assembled with emeraldine salt polyaniline (PANI-ES)-based CE generated current density (Jsc) of 12.37 mA/cm2 and power conversion efficiency (PCE) of 5.09%, which was comparable to the device prepared with Pt-based CE (PCE of 5.15%). The addition of GO is found to increase the Jsc to 12.91 mA/cm2 and the fill factor to 67% in CE containing 0.45 wt% of GO (in respect to aniline during synthesis) where the PCE is boosted to 6.12%, which is about 20% higher than Pt-based CE. The investigation of both morphological features and spectroscopic properties showed that PANI-GO nanocomposites prepared by in situ route have dissimilar protonation and oxidation states when compared with those prepared by physical mixture route. These results give insights into the role of GO in tuning PANI chemical and physical properties. Also offers a simpler and more efficient methodology for the synthesis of new CEs for DSSCs.

Chemical properties and antibacterial effect of the oil from seeds of Citrullus colocynthis

In this study, we demonstrate a one-step method for fabricating a novel lignosulfonate–graphene oxide–polyaniline (LS-GO-PANI) nanocomposite aerogel, were prepared and employed for adsorption and removal of (Pb(II)) and Cr(VI) ions from aqueous solution. The results have shown that (LS-GO-PANI) nanocomposite exhibits a very high affinity and selectivity towards Pb(II) and and Cr((VI) Ions The morphology and structure of the LS-GO-PANI ternary nanocomposite were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS)..

Chemical properties and antibacterial effect of the oil from seeds of Citrullus colocynthis

In this study, we demonstrate a one-step method for fabricating a novel lignosulfonate–graphene oxide–polyaniline (LS-GO-PANI) nanocomposite aerogel, were prepared and employed for adsorption and removal of (Pb(II)) and Cr(VI) ions from aqueous solution. The results have shown that (LS-GO-PANI) nanocomposite exhibits a very high affinity and selectivity towards Pb(II) and and Cr((VI) Ions The morphology and structure of the LS-GO-PANI ternary nanocomposite were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS)..

Facile Fabrication of a Low-Cost Lignosulfonate– Graphene Oxide–Polyaniline Ternary Nanocomposite for the Highly Efficient Removal of Pb(II) and Cr((VI) Ions from Aqueous Solutions

In this study, we demonstrate a one-step method for fabricating a novel lignosulfonate–graphene oxide–polyaniline (LS-GO-PANI) nanocomposite aerogel, were prepared and employed for adsorption and removal of (Pb(II)) and Cr(VI) ions from aqueous solution. The results have shown that (LS-GO-PANI) nanocomposite exhibits a very high affinity and selectivity towards Pb(II) and and Cr((VI) Ions The morphology and structure of the LS-GO-PANI ternary nanocomposite were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS)..

Facile Fabrication of a Low-Cost Lignosulfonate– Graphene Oxide–Polyaniline Ternary Nanocomposite for the Highly Efficient Removal of Pb(II) and Cr((VI) Ions from Aqueous Solutions

In this study, we demonstrate a one-step method for fabricating a novel lignosulfonate–graphene oxide–polyaniline (LS-GO-PANI) nanocomposite aerogel, were prepared and employed for adsorption and removal of (Pb(II)) and Cr(VI) ions from aqueous solution. The results have shown that (LS-GO-PANI) nanocomposite exhibits a very high affinity and selectivity towards Pb(II) and and Cr((VI) Ions The morphology and structure of the LS-GO-PANI ternary nanocomposite were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS)..

Graphene Oxide/Polyaniline-Based Multi Nano Sensor for Simultaneous Detection of Carbon Dioxide, Methane, Ethanol and Ammonia Gases

In this study, a multi nanosensor was fabricated for the simultaneous detection of carbon dioxide, methane, ethanol, and ammonia gases, and its electrochemical response to various concentrations of these gases were investigated. In order to fabricate this multi nanosensor, in the first phase, the Graphene-Oxide/Polyaniline (GO/PANI) nanocomposite was synthesized. Chemical composition, morphology and the structure of the nano-composite was studied by Fourier Transform InfraRed (FT-IR) spectroscopy, Field Emission-Scanning Electron Microscopy (FE-SEM), High-Resolution Transmission Electron Microscopy (HR-TEM) and X-Ray Diffraction (XRD). The results indicate that the GO successfully synthesized and the polyaniline particles are well bonded on the surface of the GO sheets. In the second phase, the formed nano-composite was placed on silver-coated electrodes and then, by placing the nanoparticles of aluminum oxide, zinc oxide, tin oxide, and titanium oxide, the different parts of the multi-nano sensor were became more sensitive toward the four mentioned gases. The responsiveness and sensitivity of the multi-nano sensor to each of the gaseswere measured by amperometric experiments and the results showed that the sensitivity of the multi-nano sensor fabricated to the detection of the above gases is acceptable. The results of the electrochemical tests showed that the response of each multi-nano sensor component to a mixture of the above four gas is defined as a four unknown equation and with considering the responses of 4 multi-nano sensor components simultaneously to the 4-gas mixture, 4 × 4unknown equations are obtained, which by solving the equation one can be found the exact concentration of each of the 4 measured gases.

Synthesis of Polyaniline/Graphene Oxide/Azobenzene Composite and Its Adjustable Photoelectric Properties

Azobenzene derivatives have fast light response characteristics; in this paper, a new azobenzene derivative (Azo) was synthesized and to be made a composite (PANI/GO/Azo) with polyaniline/graphene oxide (PANI/GO). Both composites were carefully investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Moreover, their electrochemical properties were characterized by the electrochemical workstation, including cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), cycling stability, and electrochemical impedance spectroscopy (EIS). The results demonstrated that the PANI/GO/Azo composite has a higher capacitance of 478.3 F g−1 than that of PANI/GO (359.9 F g−1) at a current density of 1 A g−1. PANI/GO/Azo composite showed excellent photosensitive electrochemical properties under UV irradiation, and its rate of capacitance change achieved about 52.57%. Additionally, the PANI/GO/Azo composite also displayed high reversibility, with specific capacitance retention of 92% after 500 cycles. Therefore, the PANI/GO/Azo electrode with a controllable electrochemical performance by UV irradiation had a great potential in the photoresponsive supercapacitor.

Study on Direct Synthesis of Energy Efficient Multifunctional Polyaniline-Graphene Oxide Nanocomposite and Its Application in Aqueous Symmetric Supercapacitor Devices.

The synthesis of promising nanocomposite materials can always be tricky and depends a lot on the method of synthesis itself. Developing such synthesis routes, which are not only simple but also can effectively catch up the synergy of the compositing material, is definitely a worthy contribution towards nanomaterial science. Carbon-based materials, such as graphene oxide, and conjugative polymers, such as conductive polyaniline, are considered materials of the 21st century. This study involves a simple one pot synthesis route for obtaining a nanocomposite of polyaniline and graphene oxide with synergistic effects. The study was carried out in a systematic way by gradually changing the composition of the ingredients in the reaction bath until the formation of nanocomposite took place at some particular reaction parameters. These nanocomposites were then utilized for the fabrication of electrodes for aqueous symmetric supercapacitor devices utilizing gold or copper as current collectors. The device manifested a good capacitance value of 264 F/g at 1 A/g, magnificent rate performance, and capacitance retention of 84.09% at a high current density (10 A/g) when gold sheet electrodes were used as the current collectors. It also showed a capacitance retention of 79.83% and columbic efficiency of 99.83% after 2000 cycles.

Preparation of Polyaniline/Graphene Oxide Thin Films Microelectrodes through Electrochemical Reduction at Different Potential Range for High-Performance Supercapacitors

In this article, the fabrication and performance of supercapacitors prepared through electrochemical reduction applied at different voltage range from polyaniline/graphene oxide (PANi/GO) thin films, which are renewable materials with an excellent yield of energy conversion is reported. The PANi/GO thin film was reduced electrochemically with different potential windows, scan rate and number of cycles which was acquired using layer-by-layer (LBL) assembly method. The resultant electrodes displayed various specific capacitances after pre-reduction with different conditions.The influence of the electrochemical reduction was investigated by Raman spectroscopy and X-ray photoelectron spectroscopy for capacitance performance. The optimum conditions were explored for supercapacitor application and an elevated specific capacitance 2619 F cm-3 (areal capacitance 18.38 mF cm-2) at 1 mV s-1 obtaining the film reduced with applied potential of -0.87 to -0.5 V. This study could introduce the new possibilities for the improvement of the electrochemical reduction effects to the composite materials for high-performance supercapacitors.

Zener-like electrical transport in polyaniline-graphene oxide nanocomposites.

The present study includes the fabrication and characterization and an investigation of the electrical transport properties of nanocomposites of n-PANI and graphene oxide (GO). The samples were prepared by loading different weight percentages D of GO during the chemical oxidative in situ polymerization of aniline monomers. Structural characterization by XRD, FTIR, FESEM, etc. confirmed that the nanocomposites exhibited superior morphology and thermal stability. The transport properties were studied by measuring the variation of conductivity with temperature T, V–I characteristics and the fundamental response Vf at different temperatures T. The dc conductance Σ showed a transition from insulator type behavior to weakly temperature dependent behavior at temperature TD, which decreased with increasing D. The V–I characteristics were generally nonlinear and the nonlinearity increased with decreasing temperature. Moreover, at temperatures T ≥ TD, the characteristics showed saturation of voltage for higher values of current, similar to Zener diodes. At lower temperatures (T ≤ TD), a voltage maximum occurred, similar to thyristors. This behavior leads to the possibility of fabricating devices containing these nanocomposites. We have tried to analyze these results using the framework of scaling theory and the concept of inter-chain hopping conduction and tunneling between conducting grains separated by insulating regimes in the nanocomposite.

In-situ temperature regulation of flexible supercapacitors by designing intelligent electrode with microencapsulated phase change materials

Benefiting from the on-going update of wearable electrical devices, flexible supercapacitors have attracted extensive attention in energy storage devices. However, the challenge still exists in achieving high electrochemical performance and cycling stability at high operating temperatures. Herein, an innovative in-situ thermal management system by rationally implanting microencapsulated phase change materials (MPCMs) into three-dimensional porous reduced graphene oxide/polyaniline (GP) frameworks on the surface of carbon nanotube film (CNF) was developed for flexible all-solid-state supercapacitors via facile one-pot electrochemical co-deposition method. The flexible sandwich-shaped all-solid-state supercapacitors using hybrid CNF/GP/MPCMs as electrodes and PVA-H2SO4 as the gel electrolyte were successfully assembled. The incorporation of MPCMs effectively suppressed the temperature fluctuation of the supercapacitor and promoted its operation stability at high temperatures. The supercapacitor containing MPCMs showed superior long-term cyclic stability in comparison with the counterpart without MPCMs. Moreover, the as-prepared supercapacitor was capable of enduring deformations of various angles and maintained 94.1% of the initial capacitance after 500 bending cycles, manifesting excellent mechanical performance. The study paves a feasible way of facilely constructing temperature regulation mechanism based on MPCMs for flexible high-performance supercapacitors.

Conductive polyaniline-graphene oxide sorbent for electrochemically assisted solid-phase extraction of lead ions in aqueous food samples

This work describes an electrochemical-assisted desorption method that has been developed for solid-phase extraction of metal ions (Pb2+), based on a well-ordered conducting sorbent: an array-like polyaniline nanofiber synthesized on the surface of graphene oxide (PANI-GO). Combining the advantages of the allowable mechanical deformation of GO with the reduced ionic-diffusion path of vertical PANI nanofibers, this method’s synergistic effect lends the prepared sorbent an enhanced stability and high analyte-desorption effectiveness. In terms of the adsorption and electrochemical-assisted desorption behavior of PANI-GO, the paper reports that the adsorption/desorption process is accompanied by the changes of the as-prepared sorbent in cyclic voltammetry, and that the prepared PANI-GO exhibits good anti-interference properties across various interference ions. Given optimal pH values, the limit of detection of the proposed method is 0.04 μg L−1; the repeatability relative standard deviation (RSD) and reproducibility RSD are 1.97% and 2.51%, respectively; and the method shows good recovery capability in the case of real beverage samples spiked with Pb2+.

Electrochemically prepared three-dimensional reduced graphene oxide-polyaniline nanocomposite as a solid-phase microextraction coating for ethion determination

Here, a three-dimensional reduced graphene oxide-polyaniline nanocomposite was synthesized and applied as a sorbent for solid-phase microextraction of ethion from water samples followed by negative corona discharge ionization ion mobility spectrometry. The nanocomposite was synthesized via a fast and facile two-step electrochemical method. The prepared sorbent was characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy and thermogravimetric analysis. The main experimental parameters in the preparation of the fiber including concentration of graphene oxide, electrodeposition time, aniline concentration, and electropolymerization time were investigated. Also, parameters affecting the extraction process (i.e., salt addition, sample stirring rate, solution pH, extraction temperature and extraction time) were studied. Under the optimal conditions, the linearity and limit of detection were found to be 1.0–70 and 0.4 μg L−1, respectively. The method presented good precision (intra-day and inter-day, n = 3), ranged from 1.7 to 4.7%. The analyte recovery obtained using spiked real water samples were in the range of 84–98%.

Polyaniline–graphene oxide nanocomposite microelectromechanical sensor for stink bugs pheromone detection

A novel polyaniline–graphene oxide nanocomposite microelectromechanical (PANI/GO/MEM) sensor was developed and applied in the detection of the synthetic pheromone of E. heros. The sensitive layer was characterized and demonstrates uniform structure with nanometric height and smooth surface. The PANI/GO/MEM sensor exhibits a linear response at concentration range 0.005 to 0.03 μg/mL, with sensitivity of 6.24 Hz/fg, detection limit of 0.91 fg/mL, quantification limit of 1.54 fg/mL, and hysteresis of 0.02 %. The PANI/GO/MEM sensor shows excellent performance and reproducibility in the exposition to volatile molecules of pheromone, with 1.1 % relative standard deviation (RSD). In this way, the results demonstrate the promising candidature of the designed PANI/GO/MEM sensor for detecting these semiochemicals, released in small quantities by the brown stink bug in the agriculture, can be a strategy for pest management.

Highly Permeable Polyaniline–Graphene Oxide Nanocomposite Membranes for CO2 Separations

Carbon dioxide (CO2) capture from fossil-fuel-based power plants requires scalable membranes with high CO2 permeability and reasonable CO2/N2 selectivity. Conventional membranes based on polyanilin...

Brush-structured sulfur-polyaniline-graphene composite as cathodes for lithium-sulfur batteries

Abstract

Achieving Ultrahigh Cycling Stability and Extended Potential Window for Supercapacitors through Asymmetric Combination of Conductive Polymer Nanocomposite and Activated Carbon.

Conducting polymers and carbon-based materials such as graphene oxide (GO) and activated carbon (AC) are the most promising capacitive materials, though both offer charge storage through different mechanisms. However, their combination can lead to some unusual results, offering improvement in certain properties in comparison with the individual materials. Cycling stability of supercapacitors devices is often a matter of concern, and extensive research is underway to improve this phenomena of supercapacitive devices. Herein, a high-performance asymmetric supercapacitor device was fabricated using graphene oxide–polyaniline (GO@PANI) nanocomposite as positive electrode and activated carbon (AC) as negative electrode. The device showed 142 F g−1 specific capacitance at 1 A g−1 current density with capacitance retention of 73.94% at higher current density (10 A g−1). Most importantly, the device exhibited very high electrochemical cycling stability. It retained 118.6% specific capacitance of the starting value after 10,000 cycles at 3 Ag−1 and with coulombic efficiency of 98.06 %, indicating great potential for practical applications. Very small solution resistance (Rs, 0.640 Ω) and charge transfer resistance (Rct, 0.200 Ω) were observed hinting efficient charge transfer and fast ion diffusion. Due to asymmetric combination, potential window was extended to 1.2 V in aqueous electrolyte, as a result higher energy density (28.5 Wh kg−1) and power density of 2503 W kg−1 were achieved at the current density 1 Ag−1. It also showed an aerial capacitance of 57 mF cm−2 at current 3.2 mA cm−2. At this current density, its energy density was maximum (0.92 mWh cm−2) with power density (10.47 W cm−2).

Swollen liquid crystalline mesophase assisted synthesis of GO-PANI nanocomposite as a fluorescent probe for purines

This article focuses on the use of graphene oxide-polyaniline (GO-PANI) nanocomposite as fluorescent probe for sensing of adenine (A) and guanine (G). Swollen liquid crystalline mesophase were used for the synthesis of graphene oxide-polyaniline nanocomposite. GO-PANI nanocomposite showed enhanced fluorescent at 441 nm (ƛexcitation = 361 nm) on interaction of purines viz A and G solutions in dimethyl sulfoxide, GO exhibited quenching at 540 nm (ƛexcitation = 261 nm). The fluorescence emission spectra of GO-PANI nanocomposite and GO were recorded in the the pressence of A and G concentrations upto 1.2 × 10−4 M. The limits of detection (LOD) calculated from the concentration dependence study for GO-PANI nanocomposite and GO are 7.5 × 10−6 M and 13.4 × 10−6 M respectively. The LOD in the case of GO is identical for both A (13.0 × 10−6) and G (13.6 × 10−6 M). The binding constant (Kb) determined for GO-PANI with purines are in the range of 0.05-0.08 × 103 M−1 which is higher in the case of GO (2.42–7.52 × 103 M−1). The lifetime measurement demonstrates, an excited state interaction of GO-PANI nanocomposite and GO with purines. This is evident from the increasing lifetime from 4.3 ns to 29.2 ns for GO-PANI nanocomposite, while 17.5 ns to 37.2 ns for GO respectively. The relatively short lifetime of the GO-PANI nanocomposite in comparison with GO suggest an electronic charge dissipation of the excited state between polyaniline and graphene oxide possibly due to the alignment of polyaniline on the graphene oxide sheet. The photopysical properties of GO-PANI nanocomposite and GO observed in this study is new and has potential for application as fluorescent probe for the detection of purines.

Electrochemical properties of reduced graphene oxide-polyaniline composite

Electrochemical properties of reduced graphene oxide-polyaniline composite

Flower-Like ZnO-Decorated Polyaniline–Graphene Oxide Nanocomposite for Electrochemical Oxidation of Imidacloprid: A Hybrid Nanocomposite Sensor

A surfactant-based soft-template method has been used to synthesize flower-like zinc oxide–polyaniline–graphene oxide (ZnO–PANI–GO) hybrid nanocomposites. Mineralization of an agricultural organic pollutant, viz. imidacloprid (Imd), in aqueous environment is investigated by cyclic voltammetry (CV) using a glassy carbon (GCE) modified with ZnO–PANI–GO hybrid nanocomposite as working electrode. CV of the modified ZnO–PANI–GO/GCE hybrid nanocomposite electrode in the presence of Imd in acetate buffer (pH 5.8) revealed an oxidation potential of 0.36 V. The linear range of detection was evaluated using Imd concentrations from 1.25 × 10−7 M to 2.12 × 10−6 M. Limits of detection and quantification of 1.3 × 10−8 M and 1.3 × 10−7 M were calculated, being the lowest reported to date compared with other techniques using nano/nanocomposite materials as probe or modified electrodes. These results suggest that hybrid nanocomposites can be cost-effective materials for detection of Imd pesticide residue. Recovery testing using various samples exhibited 100% recovery.