Bare Polyaniline Research Articles

TiO2‐WO3 nanocube‐polyaniline hierarchical membrane for efficient removal of chromium in a photocatalytic membrane reactor

AbstractIn this article, the rational design of a physically coated TiO2‐WO3 nanocube‐polyaniline photocatalytic membrane (hierarchical) reactor for the efficient reduction of chromium (VI) under visible light is discussed. The incorporation of TiO2‐WO3 in the polyaniline (PANI) membrane provides excellent hydrophilicity and high photo‐corrosion resistance and facilitates the rapid permeation of water with a flux rate of 12 L/m2 h and higher Cr (VI) reduction. The exposure of bare PANI membranes in Cr (VI) solution leads to over‐oxidation of PANI membrane and eventually leads to the destruction of the membrane. The hierarchical photocatalytic coating improves the lifetime of the membrane by blocking it from deprotonation. The photocatalytic membrane could offer 79.30% Cr (VI) reduction under visible light irradiation in a photocatalytic membrane reactor. After several reduction cycles, the membrane showed good self‐cleaning ability. The present work suggests that TiO2‐WO3 nanocube‐coated PANI hierarchical membrane is a promising approach for the reduction and removal of Cr (VI) from wastewater.

Rapid synthesis of SrTiO3 nanocubes and replacement of the high-cost platinum electrode with SrTiO3@PANI nanocomposite in dye-sensitized solar cells

In this report, SrTiO3 was synthesized in a short time (10 min) as a perfect nano-cube shaped and high-quality crystal using microwave assisted method without any further annealing process. Moreover, SrTiO3 nanocubes were incorporated into the polyaniline (PANI) structure at different amounts and resulted nanocomposites were employed in dye sensitized solar cell (DSSC) as counter electrode (CE). Incorporation of SrTiO3 nanocubes led to enlargement of active surface area and increment in electrocatalytic activity of nanocomposites, resulting in lower electron transfer resistance and excellent charge transfer kinetics at the interfaces of CE/FTO and CE/electrolyte. As a result, photovoltaic (PV) parameters of DSSC improved with incorporation of SrTiO3 nanocubes compared to the bare PANI. Furthermore, 2 wt % SrTiO3 doped PANI nanocomposite (SP2) CE exhibited a better catalytic performance in comparison to the bare PANI and Pt CEs, resulting in higher power conversion efficiency (PCE). The PCE of the DSSC with SP2 CE was extracted as 7.57 %, while the PCEs of the cells employing bare PANI and conventional Pt CEs were calculated as 5.46 % and 7.16 %, respectively. By incorporation of SrTiO3 nanocubes, the PCE of DSSC with bare PANI is enhanced as 38.7 % due to the high redox nature of SrTiO3 and expanding of active surface area stem from nanocubes of SrTiO3. The obtained results suggest that SrTiO3 can be synthesised using simple microwave assisted method in a very short time and with high quality without any further annealing procedure. Furthermore, doping of 2 wt % SrTiO3 nanocubes into PANI can be alternative to the high-cost and rare Pt for commercialization of the DSSCs in near future.

Selective and sensitive chemiresistive sensors based on polyaniline/graphene oxide nanocomposite: A cost-effective approach

In this work, the influence of Graphene oxide (GO) on the sensing performance of Polyaniline (PANI) toward NH 3 and CO gases at room temperature (RT) was comprehensively studied. The PANI/GO nanocomposite was synthesized by the “ in-situ chemical oxidation polymerization” route in the presence of GO. The optical, spectroscopic and structural properties of as-prepared materials were studied through UV–vis, FTIR, RAMAN spectroscopies and XRD. Additionally, the topological investigations of materials were carried out by Atomic Force Microscopy (AFM). The sensors were fabricated via drop-casting of the pure PANI and PANI/GO nanocomposite on a low-cost pattern of Cu interdigitated electrodes (IDE). The sensors based on the PANI/GO nanocomposite exhibited a better-sensing performance for NH 3 than those of bare PANI. The present finding indicates that the PANI/GO-based sensor exhibits high response (9.6%–70 ppm), fast recovery time (23 s), low detection limit (30 ppm) and linear dynamic range (30–230 ppm) with excellent repeatability, reproducibility, long-term stability and exceptional selectivity for NH 3 sensing. Thus, the PANI/GO-based sensor has a high potential for high-performance sensing applications.

Conducting polymers-based nanocomposites: Innovative materials for waste water treatment and energy storage

Over the years, the concept of intrinsically conducting polymers (ICP) endures to intrigue the scientific community owing to its unique properties. ICP is an organic macromolecule that integrates both the conventional polymers and metal properties into one system. The current research article discusses the simplistic methodology for the synthesis of metal oxide doped polyaniline (PANI) nanocomposites via in-situ oxidative polymerization procedure for photocatalysis and supercapacitor application. The synthesised materials are usually characterised by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and BET analysis. The photocatalytic performance of the nanocomposites is usually evaluated by monitoring the degradation of model dyes under UV irradiations whereas the supercapacitor performance is evaluated by fabricating electrodes to analyse the electrochemical efficiencies. The reported literature indicates that the conducting polymers doped nanocomposites revealed better photocatalytic and capacitance efficiencies as compared to bare PANI. Enhanced photocatalytic and electroanalytical performance, simple method for synthesis and cheaper cost of production made these materials to be exploited as potential candidates for efficient energy storage and waste water treatment.

Fabrication of visible-light assisted TiO2-WO3-PANI membrane for effective reduction of chromium (VI) in photocatalytic membrane reactor

In this work, TiO 2-WO3(40:1) nanoparticles were hydrothermally prepared and, embedded in Polyaniline (PANI) membrane with varying concentrations (3–7 wt%) and, used in photocatalytic membrane reactor for the removal of Cr(VI) from the aqueous solutions. 4-methyl piperidine (4-MP) was used as a gel inhibiting agent in N-methyl-2-pyrrolidone (NMP) solvent to prepare PANI-based flat-sheet membranes by phase inversion method. Through different characterization technique, it has been found that TiO 2-WO3 incorporated PANI membranes showed enhanced membrane properties like better hydrophilicity, better antifouling properties, higher water uptake, lower contact angle, higher porosity, and better heavy metal removal efficiency compared to bare PANI membranes. PANI membrane with 5 wt% TiO 2-WO3 exhibited a percentage rejection of 98.50% within 60 min at 0.5 MPa transmembrane pressure. Cr(VI) reduction under light and dark conditions was performed in a dead-end filtration cell with a quartz window at the top and the 5 wt% TiO 2-WO3– PANI membrane showed 67.32% reduction under visible light. TiO 2-WO3 incorporated PANI nanofiltration membranes can act as an integrated system consists of a short-circuited photo-anode and cathode under visible light irradiation. Overall, TiO 2-PANI membranes promote Cr(VI) reduction to Cr(III) in the photocatalytic membrane reactor and exhibits a better self-cleaning property.

Anchoring polyaniline molecule on 3D carbon nanotube meshwork as self-standing cathodes for advanced rechargeable zinc ion batteries

Polyaniline (PANI) is considered as an attractive cathode candidate for advanced rechargeable zinc ion batteries (ZIBs). However, the low reactivity and poor reversibility of its redox processes in neutral electrolytes generally lead to limited capacity and short lifespan. Herein, PANI molecules are strategically anchored onto three-dimensional (3D) carbon nanotube (CNT) meshwork as a self-standing cathode to solve this problem. The as-introduced 3D CNT conductive networks are capable of functioning as the electronic transmission pipelines to accelerate the electron transfer and acting as an electrolyte reservoir to maximum the intimate contact between the PANI and electrolyte, greatly facilitating the redox processes of PANI. The PANI-CNT cathode exhibits a high capacity of 240 mAh g −1 at 0.5 A g −1 , almost twice as much as the bare PANI (123 mAh g −1 ). Furthermore, the PANI-CNT electrode also delivers a superior rate capability, maintaining a decent capacity of 129 mAh g −1 with the increase of the current density to 12 A g −1 . This work sheds light on the performance optimization strategies of polymer cathodes for next-generation rechargeable zinc batteries. • The PANI anchored on 3D carbon nanotube meshwork as self-standing cathode is designed. • The highly crisscrossed CNT networks are in favor of fast electron transfer. • The PANI-CNT electrode delivers a superior capacity of 240 mAh g −1 at 0.5 A g −1 .

Room temperature ammonia sensing by CdS nanoparticle decorated polyaniline (PANI) nanorods

In the present work, a chemical co-dispersion technique is employed to develop CdS decorated polyaniline (PANI) nanocomposite. The composite film is used to develop into room temperature ammonia (NH3) sensor. Prior to sensing study, the composite films are characterized to elucidate the structural, morphological and thermal properties. Structural and morphological studies reveal attachment of CdS nanoparticles on polyaniline nanorods. Gas sensing properties of PANI-CdS composite sensor is studied thoroughly and compared with bare PANI sensor. The room temperature gas response towards acetone, ammonia, methanol, formaldehyde and ethanol is investigated and found the sensor to be selective towards ammonia. The maximum gas response of 250 % is achieved with 74 % stability for the composite sensors upon exposure of 100 ppm of NH3 at room temperature. Response and recovery times show a decreasing trend with increasing concentration of NH3 gas.

Synthesis of 2D boron nitride doped polyaniline hybrid nanocomposites for photocatalytic degradation of carcinogenic dyes from aqueous solution

This investigation focused on the photocatalytic treatment of pollutants in waste water using methylene blue (MB) and methyl orange (MO) as the model dyes. In this study, conducting polyaniline (PANI) based nanocomposites doped with 2D hexagonal boron nitride (h-BN) were synthesised using simplistic oxidative in-situ polymerization technique by employing ammonium persulfate as an initiator in acidic medium. The synthesised 2D h-BN doped PANI nanocomposites were comprehensively characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), elemental mapping, X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Degradation of MB and MO dyes under UV irradiations was performed to evaluate the photocatalytic performance of the synthesised nanocomposites. The results indicated that the h-BN nanosheets doped nanocomposites demonstrated better photocatalytic activities as compared to bare PANI or h-BN. Moreover, the nanocomposite P-BN-2, with 2 wt% of 2D h-BN nanosheets was found to be an optimal composition with 93% and 95% degradation efficiency for MB and MO within 90 min respectively.

Facile and template‐free method toward chemical synthesis of polyaniline film/nanotube structures

ABSTRACTA facile and template‐free method is reported to synthesize a new thin film structure: polyaniline (PANI) film/nanotubes (F/N) structure. The PANI F/N is a 100‐nm thick PANI film embedded with PANI nanotubes. This well‐controlled method requires no surfactant or organic acid as well as relatively low concentration of reagents. Synthesis condition studies reveal that aniline oligomers with certain structures are responsible for guiding the growth of the nanotubes. Electrical characterization also indicates that the PANI F/N possesses similar field‐effect transistor characteristics to bare PANI film. With its 20% increased surface‐area‐to‐volume (S/V) ratio contributed by surface embedded nanotubes and the excellent p‐type semiconducting characteristic, PANI F/N shows clear superiority compared with bare PANI film. Such advantages guarantee the PANI F/N a promising future toward the development of ultra‐high sensitivity and low‐cost biosensors © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3973–3979

The investigation of reduced graphene oxide@ SnO2–polyaniline composite thin films for ammonia detection at room temperature

The reduced graphene oxide@ SnO2 (GS)–polyaniline (PANI) composite was synthesized through the in situ chemical oxide polymerization for ammonia (NH3) gas detection at room temperature. The structure and morphology of resultant GS–PANI composite were characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy, respectively. The NH3 sensing performance of the composite was investigated and compared with that of the sensors based on bare PANI and GS. The results revealed that the GS–PANI composite film exhibited 160 % response (1.4 and 16 times response enhanced) to 20 ppm NH3 than that of bare PANI and GS based devices. Meanwhile, the GS–PANI based sensors displayed linearity in response and homogeneous repeatability on exposure to NH3 at room temperature.

A promising electrochemical sensing platform based on ternary composite of polyaniline–Fe2O3–reduced graphene oxide for sensitive hydroquinone determination

Abstract Hydroquinone sensors have been shown useful for a range of applications from pharmaceutical and cosmetic industry, to environmental monitoring. In this paper, we report a facile synthesize polyaniline (PANi) nanofiber incorporated into iron oxide–reduced graphene oxide (Fe2O3–rGO) and its application to construct an electrochemical hydroquinone (HQ) sensor. The ternary composite material (PANi–Fe2O3–rGO) is characterized by means of field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and voltammetric techniques. The as-prepared ternary composite further employed as novel sensing material for fabricating the hydroquinone (HQ) sensor. Compared with bare PANi and binary composite (Fe2O3–rGO), the PANi–Fe2O3–rGO ternary composite showed enhanced electrocatalytic activity to HQ oxidation. The oxidation current of HQ is linear to its concentration in the range of 1.0 × 10−7–5.5 × 10−4 M and the detection limit is found to be 6.0 × 10−8 M. The obtained detection limit and linear range for PANi–Fe2O3–rGO composite is very much comparable to the recent literature values. In addition, the fabricated sensor showed an excellent anti-interference ability against electroactive species and metal ions and proved to be useful for the estimation of the HQ in tab water with satisfactory recovery.

Reduced graphene oxide–polyaniline hybrid: Preparation, characterization and its applications for ammonia gas sensing

Here we present a useful ammonia (NH3) gas sensor based on reduced graphene oxide (RGO)–polyaniline (PANI) hybrids. PANI nanoparticles were successfully anchored on the surface of RGO sheets by using RGO–MnO2 hybrids as both of the templates and oxidants for aniline monomer during the process of polymerization. The resultant RGO–PANI hybrids were characterized by transmittance electron microscopy, infrared spectroscopy, Raman spectroscopy, UV-Vis spectroscopy, and scanning electron microscopy. The NH3 gas sensing performance of the hybrids was also investigated and compared with those of the sensors based on bare PANI nanofibers and bare RGO sheets. It was revealed that the synergetic behavior between both of the candidates allowed excellent sensitivity and selectivity to NH3 gas. The RGO–PANI hybrid device exhibited much better (3.4 and 10.4 times, respectively, with the concentration of NH3 gas at 50 ppm) response to NH3 gas than those of the bare PANI nanofiber sensor and bare graphene device. The combination of the RGO sheets and PANI nanoparticles facilitated the enhancement of the sensing properties of the final hybrids, and pave a new avenue for the application of RGO–PANI hybrids in the gas sensing field.