A novel molecularly imprinted electrochemical sensor from poly (3, 4-ethylenedioxythiophene)/chitosan for selective and sensitive detection of levofloxacin.

The improper usage of levofloxacin (LEV) endangers both environmental safety and human public health. Therefore, trace analysis and detection of LEV have extraordinary significance. In this paper, a novel molecularly imprinted polymer (MIP) electrochemical sensor was developed for the specific determination of LEV by electrochemical polymerization of o-phenylenediamine (o-PD) using poly(3,4-ethylenedioxythiophene)/chitosan (PEDOT/CS) with a porous structure and rich functional groups as a carrier and LEV as a template molecule. The morphology, structure and properties of the modified materials were analyzed and studied. The result showed that the electron transfer rate and the electroactive strength of the electrode surface are greatly improved by the interconnection of PEDOT and CS. Meanwhile, PEDOT/CS was assembled by imprinting with o-PD through non-covalent bonding, which offered more specific recognition sites and a larger surface area for the detection of LEV and effectively attracted LEV through intermolecular association. Under the optimized conditions, MIP/PEDOT/CS/GCE showed good detection performance for LEV in a wide linear range of 0.0019- 1000 µM, with a limit of detection (LOD, S/N = 3) of 0.4 nM. Furthermore, the sensor has good stability and selectivity, and exhibits excellent capabilities in the microanalysis of various real samples.

An ionic liquid-modified PEDOT/Ti3C2TX based molecularly imprinted electrochemical sensor for pico-molar sensitive detection of L-Tryptophan in milk.

L-Tryptophan (L-Trp) is essential for the human body and can only be obtained externally. It is important to develop a method to efficiently detect L-Trp in food. In this work, ionic liquid (IL) modified poly(3,4-ethylendioxythiophene)/ Titanium carbide (PEDOT/Ti3C2TX) was used as a substrate material to improve detection sensitivity. Molecular imprinted polymers (MIP) film for specific recognition of L-Trp was fabricated on the surface of modified electrodes using electrochemical polymerization. The monitoring results showed that the molecularly imprinted electrochemical sensors (MIECS) exhibited good linearity ranges (10-6 - 0.1 µM and 0.1-100 µM) with a low detection limit (LOD) of 2.09 × 10-7 µM. In addition, the MIECS exhibited remarkable stability, reproducibility, and immunity to interference. A good recovery (93.54-99.59%) was demonstrated in the detection of milk. The sensor was expected to be developed as a highly selective and sensitive portable assay, and applied to the detection of L-Trp in food.

Carbon Fiber Reinforced Recycled Polypropylene/Polyolefin Elastomer Composites with High Mechanical Properties.

The treatment of waste plastics has gradually become a hot topic in the current scientific community. In response to the needs for high-impact performance R-PP-based composites, carbon fiber (CF)-reinforced polyolefin elastomer (POE)/recycled polypropylene (R-PP) composite (CF/POE/R-PP) was prepared by the mechanical blending method, and its mechanical and thermal properties were systematically studied. It was found that the CF could effectively improve the bending and notch impact strength as well as enhance the thermal stability of POE/R-PP. Furthermore, a stable and dispersed composite interface formed by the combination of maleic anhydride-grafted polypropylene (PP-g-MAH) with the surface of CF and the fusion alkyl chains in R-PP and POE further enhanced the CF's reinforcing effect. As a result, the addition of 9 wt.% CF successfully improved the heat resistance of the composite material, and the residual carbon content increased by 97.84% after sintering. The composite toughening of POE and CF effectively improved the impact strength of the composite material, with a maximum increase of over 1000%. This study ultimately resulted in a high-impact-resistant composite material.

Self-Powered UV Photodetector Construction of the P(EDOS-TTh) Copolymer-Modified ZnO Nanoarray.

To solve the problem that zinc oxide nanorods (ZnO NRs)-based self-powered ultraviolet (UV) photodetectors cannot obtain both higher responsiveness and shorter response time, P(EDOS-TTh) was prepared using 3,4-ethylenedioxyselenphene (EDOS) and terthiophene (TTh) as copolymers, which modify the ZnO NRs surface, and the ZnO/P(EDOS-TTh) P-N junction self-powered UV device is assembled. The effect of the number of electrochemical polymerization cycles on the UV photodetection performance of ZnO/P(EDOS-TTh) P-N heterojunction was studied by adjusting the number of electrochemical polymerization cycles at the monomer molar ratio of 1:1. Benefiting from the enhanced built-in electric field of the ZnO/P(EDOS-TTh) interface, balancing photogenerated carriers, and charge separation and transport. The results show that the contact between N-type ZnO NRs and P-type P(EDOS-TTh) is best when the number of polymerization cycles is 3, due to the fact that EDOS-TTh and ZnO NRs form excellent P-N heterojunctions with strong internal electric fields, and the devices show good pyroelectric effect and UV photodetection performance. Under 0 V bias and 0.32 mW/cm2 UV irradiation, the responsivity (R) of ZnO/P(EDOS-TTh) reaches 3.31 mA/W, the detectivity (D*) is 7.25 × 1010 Jones, and the response time is significantly shortened. The rise time is 0.086 s, which exhibited excellent photoelectric properties and stability. UV photodetection performance with high sensitivity and fast response time is achieved.

Highly sensitive electrochemical sensing of norfloxacin by molecularly imprinted composite hollow spheres.

Poly (3,4-ethylenedioxythiophene) (PEDOT)-based molecularly imprinted electrochemical sensors have attracted widespread attention for monitoring contaminants in food and the environment. However, there are still problems such as poor hydrophilicity, easy agglomeration, and low selectivity in its preparation. In this work, a novel molecularly imprinted composite hollow sphere was prepared by a molecular imprinting technique using nitrogen-doped hollow carbon spheres as matrix material, and PEDOT and poly(methacrylic acid) as monomers. The selective binding capabilities and mechanism of the material to norfloxacin (NOR) were systematically investigated. Then the material-based sensor was constructed, and its electrochemical detection performance toward NOR was thoroughly studied. The sensor exhibited a wide linear range (0.0005-31 µM), a low detection limit (0.061 nM), satisfactory immunity to interference and stability. Besides, the sensor displayed better sensitivity and reliability (spiked recoveries of 98.0-105.2%, relative standard deviation of 3.45-5.69%) for detecting NOR in lake water, honey, and milk than high-performance liquid chromatography. This work provides a new strategy for developing poly(3,4-ethylenedioxythiophene)-based molecularly imprinted electrochemical sensors.

Poly (3, 4-propylenedioxythiophene)/Hollow carbon sphere composites supported Pt NPs to facilitate methanol oxidation reactions.

Direct methanol fuel cells (DMFCs) are thought of as portable, sustainable, and non-polluting energy devices. The exploration of efficient and affordable catalysts for the methanol oxidation reaction (MOR) is significant for the industrial application of DMFCs. In this study, nitrogen-doped hollow carbon spheres (HCS) derived from polydopamine were proposed for the catalyst support for platinum nanoparticles (Pt NPs) for serving as the anode catalyst for DMFCs, and a composite support material was fabricated by in-situ oxidation of 3,4-ethylenedioxythiophene (ProDOT) with HCS to get core-shell structured poly(3,4-propylenedioxythiophene) (PProDOT)-embellished hollow carbon spheres (HCS) (PProDOT/HCS) for further improving the catalytic activity for supported catalyst. The results indicated that the platinum (Pt) on the surface of HCS was well dispersed, and the Pt became smaller and more evenly distributed with the introduction of PProDOT. Simultaneously, the Schottky junction formed between PProDOT and Pt NPs contributes to enhanced charge transfer and catalytic activity of the catalyst. Notably, the core-shell structure of the ternary catalyst, its excellent charge transfer capability, and the interaction between platinum and the support contribute to its high electrocatalytic activity. Electrochemical tests demonstrated that the PProDOT/HCS/Pt catalyst exhibited a mass activity of 1169.6 mA mg-1Pt for methanol oxidation in acidic electrolytes, surpassing the activity of the HCS/Pt catalyst (472.4 mA mg-1Pt) and commercial Pt/C (281.0 mA mg-1Pt).

PEDOT-embellished Ti3C2Tx nanosheet supported Pt-Pd bimetallic nanoparticles as efficient and stable methanol oxidation electrocatalysts.

Exploiting high-efficiency and durable electrocatalysts toward the methanol oxidation reaction (MOR) is crucial for the advancement of direct methanol fuel cells (DMFCs). Herein, we demonstrate the loading of platinum-palladium bimetallic nanoparticles (Pt-Pd NPs) onto poly(3,4-ethylenedioxythiophene) (PEDOT)-embellished titanium carbide (Ti3C2Tx) nanosheets as the electrocatalyst (Ti3C2Tx/PEDOT/Pt-Pd) via a facile and rapid chemical reduction-assisted one-pot hydrothermal process. The structural and morphological analyses of Ti3C2Tx/PEDOT/Pt-Pd indicate that the three-dimensional (3D) hybrid structure formed between PEDOT and Ti3C2Tx provides a sizable active surface and more active sites, which enhances the homogeneous dispersion of the Pt-Pd NPs and facilitates mass transfer. The Schottky junctions formed between PEDOT and Pt-Pd NPs contribute to charge transfer. The electronic effects and synergistic interactions between the support and catalyst favor the electrocatalytic activity of the catalyst. The electrochemical test results reveal that the Ti3C2Tx/PEDOT/Pt-Pd catalyst has prominent electrocatalytic capability for the MOR. Compared with Ti3C2Tx/Pt-Pd and commercial Pt/C catalysts, the Ti3C2Tx/PEDOT/Pt-Pd catalyst has a larger electrochemical activity surface area (ECSA = 122 m2 g-1) and higher mass activity (MA = 1445.4 mA mg-1), as well as better CO tolerance and more reliable long-term durability (a peak current density retention of 71% after 5200 s).

Ultraviolet Photodetector Based on Poly(3,4-Ethylenedioxyselenophene)/ZnO Core-Shell Nanorods p-n Heterojunction.

In this work, we successfully assembled an organic-inorganic core-shell hybrid p-n heterojunction ultraviolet photodetector by the electropolymerization deposition of poly(3,4-ethylenedioxyselenophene) (PEDOS) on the surface of zinc oxide nanoarrays (ZnO NRs). The structures of composite were confirmed by FTIR, UV-Vis, XRD and XPS. Mott-Schottky analysis was used to study the p-n heterojunction structure. The photodetection properties of ZnO NRs/PEDOS heterojunction ultraviolet photodetector were systematically investigated current-voltage (I-V) and current-time (I-t) analysis under different bias voltages. The results showed that PEDOS films uniformly grew on ZnO NRs surface and core-shell structure was formed. The p-n heterojunction structure was formed with strong built-in electric field between ZnO NRs and PEDOS. Under the irradiation of UV light, the device showed a good rectification behavior. The responsivity, detection rate and the external quantum efficiency of the ultraviolet photodetector reached to 247.7 A/W, 3.41 × 1012 Jones and 84,000% at 2 V bias, respectively. The rise time (τr) and fall time (τf) of ZnO NRs/PEDOS UV photodetector were obviously shortened compared to ZnO UV photodetector. The results show that the introduction of PEDOS effectively improves the performance of the UV photodetector.

Electrochemical sensor formed from poly(3,4-ethylenedioxyselenophene) and nitrogen-doped graphene composite for dopamine detection.

In this study, an electrochemical sensor for dopamine (DA) detection has been developed by a composite of poly(3,4-ethylenedioxyselenophene) (PEDOS) and nitrogen-doped graphene (PEDOS/N-Gr) using an in situ polymerization method. Its structure and properties were then compared with those of the composites of poly(3,4-ethylenedioxythiophene) (PEDOT)/nitrogen-doped graphene (PEDOT/N-Gr), which were prepared by the same methods. FT-IR, Raman, UV-vis, XPS, mapping and SEM investigated the structure and morphology of these composites. These revealed that PEDOS/N-Gr had a higher conjugation degree than PEDOT/N-Gr. The synergetic effect between PEDOS and N-Gr was beneficial for the formation of a homogenous surface coating. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were conducted for electrochemical detection of DA. Compared with PEDOT/N-Gr, the PEDOS/N-Gr displayed an enhanced sensitivity and electrocatalytic performance for DA detection with linear ranges of 0.008-80 µM (PEDOT/N-Gr: 0.04-70 µM) and limits of detection (LOD) of 0.0066 µM (S/N = 3) (PEDOT/N-Gr: 0.018 µM (S/N = 3)).

One-pot self-assembly preparation of thiol-functionalized poly(3,4-ethylenedioxythiophene) hollow nanosphere/Au composites, and their electrocatalytic properties.

In this work, we developed a thiol-functionalized poly(3,4-ethylenedioxythiophene) hollow sphere (poly(EDOT-MeSH)/Au) polymer through a simple one-pot self-assembly method using polyvinylpyrrolidone (PVP) as a soft template. The monomer was used as both a reductant and a stabilizer to decorate gold nanoparticles (Au NPs). FTIR, XRD, EDX, SEM and TEM analyses were used to characterize the composite hollow spheres. The chemical bond between S and Au was confirmed by XPS. The electrochemical performance of the composite hollow spheres was determined by cyclic voltammetry (CV) and an ampere response timing current test. The results revealed that the poly(EDOT-MeSH)/Au hollow-sphere-based electrochemical sensor possesses excellent conductivity and high redox reversibility with detection limits (S/N = 3) of 0.2, 0.02, 0.08 and 0.05 µM in the linear ranges of 0.1-650 µM, 0.05-100 µM and 0.1-600 µM for the determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and nitrate ions (NO2 -), respectively. The preparation method for these composites will further the development of this type of conducting polymer/gold nano-composite material modified electrochemical sensor for biological species.

Electrochemical synthesis of hydroxyl group-functionalized PProDOT/ZnO for an ultraviolet photodetector.

Ultraviolet (UV) detectors based on zinc oxide (ZnO) nanorods (NRs) are ideal materials for UV radiation detection. However, owing to the surface effect of ZnO NRs, their speed of photoresponse and photosensitivity need to be improved. In this study, a UV photodetector was fabricated via electrochemical coating of poly(3,4-propylenedioxythiophene) grafted with functional groups (-OH) on a hydrothermally grown ZnO NRs. For comparison, poly(3,4-propylenedioxythiophene)/ZnO composites were synthesized using the same method. The structure of the composite film was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The effect of the polymer structure on the UV sensing ability of ZnO NRs was evaluated by fabricating a UV detector with a composite material. The structural results indicated that the PProDOT-type conductive polymer and ZnO composites were successfully synthesized. The UV photodetection results showed that the presence of functional groups (-OH) in polymer chains could enhance the responsivity of the material. The response time of the ZnO/PProDOT-OH composite was 15 s shorter than that of the ZnO/PProDOT composite. A rise in photocurrent induced an increase from 2.5 A W-1 to 34.75 A W-1 in the UV photoresponsivity of the ZnO/PProDOT-OH composite, compared with that of the pure ZnO NRs. The external quantum efficiency and detectivity significantly improved, the increases of which were attributed to the coupling of the polymer and ZnO NRs.

Electrochemical synthesis of multilayered PEDOT/PEDOT-SH/Au nanocomposites for electrochemical sensing of nitrite.

A multilayered film of poly(3,4-ethylenedioxythiophene)/poly(thiomethyl 3,4- ethylenedioxythiophene)/gold nanoparticle (PEDOT/PEDOT-SH/Au) nanocomposites was successfully synthesized on indium tin oxide (ITO) and glassy carbon electrode (GCE) via an electrochemical technique. The structure and morphology of the composite was characterized by FT-IR, UV-vis, EDS, XPS, and SEM analyses. The prepared multilayered PEDOT/PEDOT-SH/Au nanocomposite was used for the electrochemical catalytic oxidation of nitrite by amperometry. The results showed that the microstructures of PEDOT/PEDOT-SH/Au nanocomposites are not strongly dependent on the substrate. Fibrous PEDOT as hard template absorbed EDOT-SH on it to form porous PEDOT/PEDOT-SH. Porous structure had the advantages of large specific surface area and high porosity for nitrite ion adsorption. The thiol group in PEDOT/PEDOT-SH stabilized Au nanoparticles (NPs) effectively through Au-S bond and allowed Au NPs to have high dispersion and excellent electrocatalytic activity. The PEDOT/PEDOT-SH/Au composite prepared on GCE had a good performance in its electrochemical response to nitrite ions. PEDOT/PEDOT-SH/Au/GCE displayed a low oxidation potential (0.74 V), a fast response time (< 3 s), a low detection limit (0.051 µM), two linear ranges (0.15-1 mM and 1-16 mM), good sensitivity (0.301 µA µM-1 cm-2 and 0.133 µA µM-1 cm-2) with good reproducibility, stability, and selectivity. Graphical abstract Schematic representation of the preparation process of the nitrite ion electrochemical sensor.

Self-assembly of pendant functional groups grafted PEDOT as paracetamol detection material.

In this paper, pendant functional group grafted EDOTs, such as EDOTCH2NH2, EDOTCH2OH and EDOTCH2SH, were selected as monomers for the preparation of their respective polymers via a common chemical oxidative polymerization method in the absence of CTAB by varying the [monomer]/[oxidant] ratios. The self-assembly mechanism of the polymers was systematically studied by discussing the hydrogen bonding effect, acidity and electron-donating ability, as well as the chain initiation and chain growth of the chemically oxidated polymerized monomers. These functional group grafted PEDOTs were applied to the electrochemical determination of paracetamol (PAR) to further investigate the effect of the pendant functional groups (-SH, -OH, -NH2) on the electrochemical sensing behaviour of the polymers. The results indicated that the hydrogen bonding effect of the pendant functional groups was vital to the self-assembly of the polymer chains, and the PEDOTs with -OH and -SH groups had a tendency to self-assemble into a spherical structure, while the PEDOT with an -NH2 group exhibited a fibrous structure. The electrochemical response of PEDOTs with functional groups was better than that that of PEDOT alone, and the highest electrochemical response was observed in PEDOT with an -SH group ([monomer]/[oxidant] = 1 : 8).

Electrochemical Sensor of Double-Thiol Linked PProDOT@Si Composite for Simultaneous Detection of Cd(II), Pb(II), and Hg(II).

Heavy metal ions in water, cosmetics, and arable land have become a world-wide issue as they cause a variety of diseases and even death to humans and animals when a certain level is exceeded. Therefore, it is necessary to development a new kind of sensor material for the determination of heavy metal ions. In this paper, we present an electrochemical sensor based on composite material (thiol(-SH) grafted poly(3,4-proplenedioxythiophene) (PProDOT(MeSH)2)/ porous silicon spheres (Si) composite, denoted as PProDOT(MeSH)2@Si) from the incorporation of thiol(-SH) grafted poly(3,4-proplenedioxythiophene) (PProDOT(MeSH)2) with porous silicon spheres (Si) for the electrochemical detection of heavy metal ions (Cd(II), Pb(II), and Hg(II)). The PProDOT(MeSH)2@Si composite was synthesized via a chemical oxidative polymerization method. The structure and morphology of PProDOT(MeSH)2@Si composite were characterized by Fourier transform infrared (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), scanning electron microscope (SEM), Transmission electron microscope (TEM), and Brunauer-Emmett-Teller (BET). Furthermore, the electrochemical performance of PProDOT(MeSH)2@Si was evaluated by detecting of Cd(II), Pb(II), and Hg(II) ions using the differential pulse voltammetry (DPV) method. The relationship between structural properties and the electrochemical performance was systematically studied. The results showed that the entry of two thiol-based chains to the monomer unit resulted in an increase in electrochemical sensitivity in PProDOT(MeSH)2, which was related to the interaction between thiol group(-SH) and heavy metal ions. And, the combination of PProDOT(MeSH)2 with Si could improve the electrocatalytic efficiency of the electrode material. The PProDOT(MeSH)2@Si/GCE exhibited high selectivity and sensitivity in the rage of 0.04 to 2.8, 0.024 to 2.8, and 0.16 to 3.2 µM with the detection limit of 0.00575, 0.0027, and 0.0017 µM toward Cd(II), Pb(II), and Hg(II), respectively. The interference studies demonstrated that the PProDOT(MeSH)2@Si/GCE possessed a low mutual interference and high selectivity for simultaneous detection of Cd(II), Pb(II), and Hg(II) ions.

A bromine-catalysis-synthesized poly(3,4-ethylenedioxythiophene)/graphitic carbon nitride electrochemical sensor for heavy metal ion determination.

In this paper, poly(3,4-ethylenedioxythiophene)/graphitic carbon nitride (PEDOT/g-C3N4) composites were prepared by the bromine catalysed polymerization (BCP) method with varying weight ratios of monomer to g-C3N4. For comparison, solid-state polymerization (SSP) and metal oxidative polymerization (MOP) methods were also used for the synthesis of PEDOT/g-C3N4 composites. Electrochemical determination of heavy metal ions (Cd2+ and Pb2+) was carried out by differential pulse voltammetry (DPV) on composite-modified glass carbon electrodes (GCEs), which were prepared by different methods. The obtained composites were analysed by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible absorption spectroscopy (UV-vis), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that the bromine catalysed polymerization (BCP) method is an effective way to prepare the PEDOT/g-C3N4 composite, and the combination of PEDOT with g-C3N4 can improve the electrochemical activity of electrode materials. And, the composite from the BCP method modified electrode (PEDOT/10 wt% g-C3N4/GCE) exhibited the widest linear responses for Cd2+ and Pb2+, ranging from 0.06-12 µM and 0.04-11.6 µM with detection limits (S/N = 3) of 0.0014 µM and 0.00421 µM, respectively.

An Electrochemical Sensor of Poly(EDOT-pyridine-EDOT)/Graphitic Carbon Nitride Composite for Simultaneous Detection of Cd2+ and Pb2.

In this study, poly(2,5-bis(3,4-ethylenedioxythienyl)pyridine)/graphitic carbon nitride composites (poly(BPE)/g-C3N4) were prepared by an in situ chemical polymerization method. Composites were characterized by using Fourier transform infrared spectroscopy (FT-IR), ultraviolet⁻visible absorption spectra (UV⁻vis), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Furthermore, electrochemical sensors were applied for the electrochemical determination of Cd2+ and Pb2+ using the differential pulse voltammetry (DPV) method. The results indicated that 10 wt % poly(BPE)/g-C3N4 composite-modified electrode exhibited linear detection ranging from 0.12 to 7.2 μM and 0.08 to 7.2 μM for Cd2+ and Pb2+, with detection limits (S/N = 3) of 0.018 μM and 0.00324 μM. Interference analysis suggested that the 10 wt % poly(BPE)/g-C3N4-modified electrode can be applied for the detection of the Cd2+ and Pb2+ in real samples.

Solid-State Heating Synthesis of Poly (3,4-Ethylenedioxythiophene)/Gold/Graphene Composite and Its Application for Amperometric Determination of Nitrite and Iodate.

A ternary composite of poly (3,4-ethylenedioxythiophene)/gold/graphene (PEDOT/Au/GO) for promising electrochemical sensor was synthesized by solid-state heating method. The interaction between the PEDOT, Au, and GO explored for detection of nitrite and iodate. It was found that the PEDOT/Au/GO composite had shale-like morphology with a uniform distribution of gold nanoparticles. Electrochemical experiments showed that the PEDOT/Au/GO composite modified electrode exhibited good electrocatalytic activity toward determination of iodate. The amperometric experiments at the PEDOT/Au/GO/GCE revealed that a good linear relationship existed between peak current and the concentration in the range of 100-1000 µM with the detection of 0.53 and 0.62 µM (S/N = 3) for nitrite and iodate, respectively. Moreover, the current response of PEDOT/Au/GO/GCE for nitrite and iodate at 10 µM was up to 9.59 and 11.47 µA, respectively. Mechanisms of the direct electron transfer between ion(nitrite or iodate)and the PEDOT/Au/GO composite.

Photodegradation of methylene blue by photocatalyst of D-A-D type polymer/functionalized multi-walled carbon nanotubes composite under visible-light irradiation.

A donor-acceptor-donor (D-A-D) type monomer (3,6-bis(2-(3,4-ethylenedioxy- thiophene))pyridazine) (EPE) with pyridazine as intermediate unit (acceptor) and 3,4-ethylenedioxythiophene (EDOT) as sealing unit (donor) was successfully synthesized. The functionalized multi-walled carbon nanotubes (f-MWCNT) was covalently linked with polymer chain via chemical oxidative polymerization of monomer EPE to form poly(EPE)/f-MWCNT composite. The prepared composite was characterized by Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible absorption spectra (UV-vis), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), and Field emission scanning electron microscope (FESEM), respectively. The photocatalytic activity of poly(EPE)/f-MWCNT was investigated toward degrading methylene blue (MB) dye solution (1 × 10-5 M) under visible light irradiation. As expected, the degradation efficiency of poly(EPE)/f-MWCNT is significantly higher than that of either pure poly(EPE) or poly(EPE)/MWCNT for MB dye, especially the kinetic constant of poly(EPE)/f-MWCNT is more than 6 times of poly(EPE)/MWCNT. Besides, the reactive oxygen species trapping experiments indicate that the degradation of MB over the poly(EPE)/f-MWCNT composite mainly results from holes oxidation. Moreover, the enhancement of the photodegradation rate is mainly attributed to the superior stability, strong light absorption ability, and highly effective photo-generated electron-hole pairs of the poly(EPE)/f-MWCNT composite. A reasonable mechanism for the enhanced reactivity was proposed.

Functionalization of Graphene Oxide and its Composite with Poly(3,4-ethylenedioxythiophene) as Electrode Material for Supercapacitors.

In this study, poly(3,4-ethylenedioxythiophene)/thiophene-grafted graphene oxide (PEDOT/Th-GO) composites from covalently linking of Th-GO with PEDOT chains were prepared via in situ chemical polymerization with different weight percentage of Th-GO ranging between 40 and 70 % in reaction medium. The resulting composite materials were characterized using a various analytical techniques. The structural analysis showed that the composites displayed a higher degree of conjugation and thermal stability than pure PEDOT, and the weight percentage of Th-GO could affect the doping level, amount of undesired conjugated segments, and porous structure of composites. Electrochemical analysis suggested that the highest specific capacitance of 320 F g(-1) at a current density of 1 A g(-1) with good cycling stability (capacitance retention of 80 % at 1 A g(-1) after 1000 cycles) was achieved for the composite prepared from 50 wt% Th-GO content in reaction medium.

Preparation of PEDOT/GO, PEDOT/MnO2, and PEDOT/GO/MnO2 nanocomposites and their application in catalytic degradation of methylene blue.

The nanocomposite materials of poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO), poly(3,4-ethylenedioxythiophene)/MnO2 (PEDOT/MnO2), and poly(3, 4-ethylenedioxythiophene)/graphene oxide/MnO2 (PEDOT/GO/MnO2) were successfully prepared by facile and template-free solution method. The structure and morphology of nanonanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible absorption spectra (UV-vis), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX), respectively. The catalytic activities of nanocomposites were investigated through the degradation processes of methylene blue (MB) solution under dark, UV light, and nature sunlight irradiation, respectively. The results displayed that nanocomposites were successfully synthesized, and PEDOT/GO had higher conjugation length and doped degree than pure PEDOT. However, the introduction of MnO2 could lead to the reduction of conjugation length and doped degree in PEDOT/MnO2 and PEDOT/GO/MnO2 nanocomposites. The field emission scanning electron microscope (FESEM) analysis also showed that both MnO2 and GO had some effect on the morphology of nanocomposites. The catalytic activities of pure PEDOT and nanocomposites were in the order of PEDOT/GO/MnO2 > PEDOT/MnO2 > PEDOT/GO > pure PEDOT. Besides, the catalytic results also showed that the highest degradation efficiency of MB after 7 h occurred in the PEDOT/GO/MnO2 composite in three irradiation.