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With a classical trajectory Monte Carlo model, we systematically study the laser intensity and field amplitude ratio dependence of nonsequential double ionization by counter-rotating two-color circularly polarized fields (800 and 1600 nm). The results show that the optimized field amplitude ratio changes with the laser intensity, which is attributed to the shift of the most probable amplitude ratio of electron returning with the laser intensity. Moreover, the laser intensity-dependent double ionization probability curve shows a remarkable dip in the transition region between the nonsequential and sequential channels. It can be well explained by the reduction of the probability of electron returning with the increase of the laser intensity. [ABSTRACT FROM AUTHOR]

Since the synthesis of non-oxidized ceramic and alloy powders requires both high temperature and oxygen insulation conditions, here we demonstrate a cost-efficient molten salt sealing/shielded synthesis method with dynamic gas tightness. Compared to conventional synthesis method, it can prevent the loss of reaction materials at high temperature, cut off the connection between reacting material and outside air, and does not require long-time ball milling mixing treatment or provision of applied pressing before or during heating. Only low-cost salts (e.g., NaCl, KCl), a few minutes of raw material mixing, and regular heating molds are required to obtain high-purity (>96 wt%), micron-sized Ti 3 AlC 2 and Ti 3 SiC 2 powders with narrow size distribution, which significantly decreased the complexity and production costs in the synthesis process. The effect of temperature and raw material content on the products were investigated. The mechanism of diffusion reaction between reactants in molten salt environment was analyzed. The new method developed here was also applicable to Ti 2 AlC, V 2 AlC and Cr 2 AlC MAX phases, as well as provided new ideas for the preparation of other MXenes precursors with certain stoichiometric ratios, air-sensitive materials and nanopowders. [ABSTRACT FROM AUTHOR]

Although all-inorganic lead halide perovskite nanocrystals (NCs) have attracted great attention, the intrinsic toxicity of lead remains to be resolved. Doped CsBr NCs have recently proved to be a new promising candidate of lead-free NCs, but the low photoluminescence quantum yield (PLQY) and the difficulty in the fine modulation of chrominance are still the current challenges. Herein, environment-friendly Cu doped CsBr (Cu:CsBr) NCs were synthesized with good stability and high PLQY (∼38.8%) by using a facile one-pot colloidal synthesis approach. Moreover, for the first time, Mn was introduced into the Cu:CsBr NCs, resulting in dual-emission from Cu and Mn dopants. By controlling the doping amounts of Mn, the co-doped CsBr NCs with flexibly controlled two emission peak intensities and chrominance could be realized. The current co-doping method can not only realize fine modulation of chrominance but also avoid the instability induced by mixed halide. Finally, as-synthesized NCs can be employed as an efficient color conversion layer for fabricating phosphor-converted LEDs. [ABSTRACT FROM AUTHOR]

In this study, Al 2 O 3 ceramic and Cu bars were brazed with newly designed Ag–Cu–Ti(ABA)+Zn composite fillers. Systematic analysis of the microstructure of the brazed joints indicated that the volatilization of Zn atoms during the brazing process could promote the spreading of liquid brazing fillers on the surface of the Al 2 O 3 ceramic, resulting in a uniform dendritic interfacial structure. The typical interfacial structure was an Al 2 O 3 /TiO/(Cu, Al) 3 Ti 3 O+Ag(s, s)/Cu interface. Notably, the tensile strength was improved to 20.89 MPa for Al 2 O 3 /Cu joint brazed with ABA+Zn composite fillers at 900 °C for 20 min, approximately 67.6% higher than the sample brazed without Zn foil. In this case, the fracture model was straight and sharp-angled inside the Al 2 O 3 ceramic. In addition, the joint strength decreased with increased brazing temperatures from 900 to 940 °C. [ABSTRACT FROM AUTHOR]

High‐entropy (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C ceramics (HEC) are fabricated via spark plasma sintering using different die configurations, including the conductive and insulating dies. Compared to the conductive die, the grain sizes of samples sintered in the insulating die are significantly larger, which is attributed to the higher local temperature as a result of the higher current density in the sample. Furthermore, the microstructure evolution and grain growth mechanism of HEC are investigated for the first time. We find that at moderate temperatures (∼1600°C), the grain growth of HEC can occur by a grain coalescence mechanism, forming numerous irregular grains in the porous sample. Three factors are crucial to induce grain coalescence, including the formation of partial melting layers on particle surfaces, nanograin rearrangement via rotation and sliding, and the formation of low‐angle grain boundaries. During the final sintering stage, the irregular grains will change into polyhedral shapes by grain boundary migration. These findings are of assistance to better understand and control the microstructure evolution of HEC and other ultrahigh‐temperature carbide ceramics. [ABSTRACT FROM AUTHOR]

Ti 2 AlN powders were synthesized through molten salt method and re-calcination process using TiH 2 , Al and TiN powders as raw materials at 1100 ℃. The composition of final composite was directly influenced by the initial Al and TiH 2 content in the starting mixture. The purity of the synthesized Ti 2 AlN powder could reach 97.1 wt% when the Al molar ratio was 1.05. Then high strength Ti 2 AlN ceramics were successfully prepared in different modes, including two forms of pulse electric current sintering (PECS/SPS) and hot-pressing sintering (HP). A record-high flexural strength of 719 MPa was obtained for the PECS/SPS with an electrical insulating die (PECS/SPS II) sintered sample, based on the synthesized powder in which the initial molar ratio of Al was 1.1. The sintering behaviors in various modes were analyzed, confirming the shrinkage of particles starting at lower temperature in PECS/SPS II. The density, microstructure, Vickers hardness and elastic modulus of sintered ceramics were also investigated. Therefore, the present work provided the new methods about powder preparation and ceramic sintering of Ti 2 AlN, making it possible to be used as high strength structural ceramics. [ABSTRACT FROM AUTHOR]

Flash sintering (FS) is an important technique in the field of ceramic sintering. Nevertheless, conventional FS is less attractive for practical applications because of the complex shapes and small sizes of the specimens. In this study, using the novel electric field‐assisted hot pressing (FAHP) technique, we successfully achieved FS during the net‐shape hot pressing (HP) process for the first time. It was found that the 3 mol% yttria‐stabilized zirconia (3YSZ) can be flash sintered at 909°C using a fairly low DC field of 33 V/cm under 30 MPa pressure. The grain sizes of the FAHP‐sintered samples were 20% smaller than that of the HP‐sintered sample. When the current density limit is ≥240 mA/mm2, 3YSZ can be fully densified during the flash events. Careful analysis of the sintering curves suggests that although the carrier type or concentration is changed during flash events, it cannot explain the ultrafast densification. Additionally, we devised a qualitative method to analyze the densification mechanism. The results indicated that the ultrafast densification observed during flash events resulted from the synergistic effects of the rapid heating rate and peak sample temperature. Finally, the atomic force microscopy confirmed the lower grain boundary energy for the FAHP‐sintered samples, which accounts for the smaller grain sizes than the HP‐sintered sample. We believe that the FAHP technique could create new possibilities for theoretical and applied research on field‐assisted sintering techniques. [ABSTRACT FROM AUTHOR]

Two strategies have been extensively employed to develop advanced accident tolerant fuels (ATF): improving thermal conductivity and producing large grain sized pellets. However, there are few reports on the simultaneous utilization of both strategies. In this work, we fabricated Mo–Cr alloy reinforced UO 2 (UMC) composite pellet with both high thermal conductivity and large grain size by a simple in-situ alloying method for the first time. The average grain size of UO 2 increased from 6 μm to 113 μm. Thermal conductivity of the UMC pellet (with 2 vol% Mo) at 1200 °C increased by 36.46% compared with pure UO 2. The increase rate of thermal conductivity per 1 vol% dopant reached about 18%. The Mo–Cr alloy formed continuous micro-cell layer around UO 2 particles. Such continuous micro-cell Mo–Cr alloy layer and increase of UO 2 grain size both helped improve the thermal conductivity of UMC composite pellets. Thermal expansion coefficient of the UMC under the operating temperature decreased by 11.90% compared with pure UO 2. The oxidation resistance of the UMC pellet under high temperature steam was also improved. This work provides a new strategy towards fabricating ATF with both high thermal conductivity and large grain size. [ABSTRACT FROM AUTHOR]

A novel alternating current-assisted sintering (ACS) technology was applied to prepare Al 2 O 3 ceramics. The results show that, compared to conventional pressureless sintering (PS), the ACS method has remarkable advantages in reducing the sintering temperature and shortening sintering time. Specifically, submicron dense Al 2 O 3 ceramics could be obtained by ACS with a soaking time of 5 min and a sintering temperature of 1400 °C. A higher sintering temperature (1500 °C) and longer soaking time (1 h) were necessary for PS to reach a similar density. The maximum flexural strength and hardness of alternating current-assisted sintered (ACSed) samples were 864 MPa and 19.24 GPa, respectively. For the ACSed and pressureless sintered (PSed) samples whose densities and grain sizes were similar, the flexural strength of the ACSed ones was more than 50% higher than that of the PSed ones. The results suggest that the key to achieving rapid densification is the fast heating rate and mechanical load. In conclusion, the ACS technology, whose cost is lower than spark plasma sintering (SPS), is a viable alternative for preparing high performance Al 2 O 3 ceramics. [ABSTRACT FROM AUTHOR]

In the present work, high‐quality MgSiN2 powders were prepared by a combustion synthesis method, based on Mg‐Si3N4‐N2 system. The effects of additive content (NH4Cl or NH4F) and N2 pressure on phase composition and crystal morphology of products were investigated. The results suggested that both NH4Cl and NH4F additives alleviated agglomeration and decreased the grain size of MgSiN2. In addition, NH4Cl did not result in the formation of an extra impurity, while MgF2 residue was found when NH4F was introduced. Therefore, NH4Cl additive was considered as a better choice for the preparation of MgSiN2 powders in comparison with NH4F additive. According to the observation of some MgSiN2 whiskers and notably increased Si content under low N2 pressure, the pressure of N2 over 0.5 MPa was essential to have a complete reaction in the present work. Finally, MgSiN2‐Si3N4 composite powders with quasi‐spherical morphology were prepared by adding excessive Si3N4 and NH4Cl additive in reactant. The formation and growth mechanism of MgSiN2 grains was reasonably speculated based on the experimental results. Because of the remarkable merits, the as‐prepared Si3N4‐MgSiN2 composite powders showed great potential for alternative sintering aid in the sintering of Si3N4‐based ceramics. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a readily available copolymer that comes as an aqueous dispersion with good processability. A flexible voltammetric sensor for the widely used food stabilizer tert.-butylhydroquinone (TBHQ) was constructed by using a film of PEDOT:PSS. The electron transfer efficiency of the electrode was enhanced by doping with dimethyl sulfoxide (DMSO), and mass transport at the electrode-electrolyte interface was increased by adding the cationic surfactant cetyltrimethylammonium bromide (CTAB) which acts as a sorbent for TBHQ. SEM, AFM, XPS, UV − vis and electrochemical analysis were conducted to characterize the properties of the electrode. After optimization of the experimental conditions, the electrode operated at a working potential of 0.17 V (vs. SCE) has a linear response in the 0.5–200 μM TBHQ concentration range and a lower detection limit of 0.15 μM (at S/N = 3). It was applied for the determination of TBHQ in spiked real samples, and recoveries ranged between 96.85 and 103.41%. [ABSTRACT FROM AUTHOR]

Abstract In this work, electrode based on poly(3,4-ethylenedioxythiophene) (PEDOT) was employed for the fabrication of an efficient sensor for 4-chloro-3-methylphenol (PCMC) detection. To improve the dispersity and increase the specific surface area of PEDOT, core-shell structured UiO-66-NH 2 @PEDOT was designed by in-situ oxidation method using Zr-based metal-organic framework (UiO-66-NH 2) as template. In addition, to achieve a further increased active surface area and electron transfer rate of the modified materials, graphene aerogel (GA) was utilized as substrate material for the assembly of UiO-66-NH 2 @PEDOT. Then, the obtained UiO-66-NH 2 @ PEDOT/GA modified electrode was employed as an electrochemical sensor for PCMC detection. Experiment parameters, such as pH value of acetate buffer solution and accumulation time, were optimized in detail. Under the optimized experiment condition, the UiO-66-NH 2 @PEDOT/GA electrode showed a good linear range of 0.6–18 μM, as well as a low detection limit of 0.2 μM (S/N = 3). The UiO-66-NH 2 @PEDOT/GA electrode was applied toward the detection of PCMC in tap water with good recovery. All these features suggest that the prepared PEDOT-based composite could serve as a promising sensing platform for monitoring water pollutants. Graphical abstract 3D UiO-66-NH 2 @PEDOT/GA modified electrode as an electrochemical sensor was employed for 4-chloro-3-methylphenol detection. Unlabelled Image Highlights • A novel 3D UiO-66-NH 2 @PEDOT/GA composite was obtained through facial approach. • UiO-66-NH 2 @PEDOT/GA electrode was applied for the electrochemical detection of PCMC. • Low detection limit and wide linear range for PCMC were obtained. • The method can detect PCMC in tap water with good recovery. [ABSTRACT FROM AUTHOR]

Abstract A highly-sensitive electrochemical sensor based on single walled carbon nanotubes (SWCNTs) nanocomposite electro-catalyst supported molecularly imprinted poly(3,4-ethylenedioxythiophene) (PEDOT) film modified with two-dimensional layered tungsten sulfide (WS 2 ) nanosheet for the detection of vitamin B 2 (VB 2 ) was successfully developed. Molecularly imprinted WS 2 -PEDOT film was prepared by the electrochemical co -polymerization of functional monomer 3,4-ethylenedioxythiophene in the presence of template molecule VB 2 and WS 2 nanosheet. SWCNTs nanocomposite modified electrode was obtained by drop-coating SWCNTs dispersion containing graphene oxide (GO) onto GCE surface. WS 2 was used for improving the denseness and smoothness in the morphology and structure of PEDOT. GO was employed for enhancing the electro-catalytic capacity of SWCNTs and the interaction with template molecule via functional groups. The imprinted sensor was characterized, and its performance and parameters were investigated and optimized using linear sweep voltammetry. Under optimized conditions, the prepared imprinted sensor displayed a good linear response to VB 2 in wide concentration ranges from 0.002 to 0.9 μM with a low detection limit of 0.7 nM, and successfully applied to electrochemically detect VB 2 in drug samples with good reproducibility, repeatability and storage stability. The new design for the facile fabrication of mimic electrode will open up a new horizon in the development of highly-sensitive biomimic/imprinted sensors. Graphical abstract Unlabelled Image Highlights • A novel electrochemical sensor based on graphene oxide-SWCNTs supported WS 2 -MIPs film was developed. • WS 2 -MIPs film was prepared by the electropolymerization of EDOT in the presence of VB 2 and WS 2 nanosheets. • The developed sensor was successfully used for VB 2 detection in real samples with good performance. [ABSTRACT FROM AUTHOR]

Conductive poly(3,4-ethylenedioxythiophene) (PEDOT) composites have emerged as potential candidates for electrochemical biosensors, however, the sensing performance was mainly relied on their structure and composition. In this work, a novel three-dimensional (3D) structural nano-PEDOT-graphene aerogel (nano-PEDOT-GA) composite was designed via the in-situ polymerization of nano-PEDOT on porous 3D GA. SEM revealed that the introduction of GA could induce the growth of worm-like PEDOT. Subsequently, Au nanoparticles (AuNPs) were directed to nano-PEDOT-GA surface by electrodeposition method. Featuring the excellent biocompatibility, high specific surface area and good conductivity of AuNPs/nano-PEDOT-GA, a highly sensitive label-free immunosensor was developed using AuNPs/nano-PEDOT-GA as signal amplification platform for detecting prostate specific antigen (PSA). Under the optimal conditions, the fabricated immunosensor presented a good linear in the analytical range of 0.0001–50 ng mL −1 with a low detection limit of 0.03 pg mL −1 (S/N = 3), high selectivity against other serum interfering substance and good stability and reproducibility, which provides a promising platform for the clinical immunoassay of PSA. [ABSTRACT FROM AUTHOR]

A sensitive Pb(II) sensor was fabricated based on Co 3 O 4 /reduced graphene oxide/chitosan (Co 3 O 4 /rGO/chitosan) nanocomposite modified glassy carbon electrode (GCE). The Co 3 O 4 /rGO material was synthesized through in situ growth of Co 3 O 4 nanoparticles (NPs) on GO and subsequent hydrazine reduction process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that Co 3 O 4 NPs with a diameter of around 100 nm are attached on rGO sheets. The structures and compositions of Co 3 O 4 /rGO were further characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Many experimental parameters, such as pH value, deposition time and deposition potential were optimized. Under optimal conditions, the calibration plot for Pb(II), with data acquired at − 0.556 V ( vs . SCE) is linear in the concentration range from 1.0 to 200.0 nM. Combining the good conductivity and high surface area of rGO, strong Pb(II) adsorption ability of Co 3 O 4 NPs, and excellent Pb(II) complex-forming ability of chitosan, the nanocompsite provides a sensitive Pb(II) senor with a detection limit of 0.35 nM. Moreover, the positively charged chitosan can interact with the negatively charged rGO to increase the stability of Co 3 O 4 /rGO nanocomposite. The hybrid nanocomposite Pb(II) senor provides new opportunity for vegetable analysis. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene) (PEDOT) as a potential molecularly imprinted polymer (MIP) for the promising application in different fields is being closely concerned, but the denseness and smoothness in the morphology and structure of PEDOT hinder the application of the imprinted PEDOT film. In this paper, a simple voltammetric sensor with high sensitivity and selectivity based on the imprinted PEDOT film with imprinted sites as a recognition element for the trace analysis of vitamin K 3 (VK 3 ) in poultry drug samples was developed by the one-step electro-polymerization of commercially-available monomer 3,4-ethylenedioxythiophene in the presence of the template molecule VK 3 . The imprinted PEDOT/GCE could efficiently discriminate VK 3 from its structural analogs, and the imprinted PEDOT sensor displayed good linearity with VK 3 concentrations in the wide range of 0.009 to 35 μM with a low limit of detection 0.00031 μM under the optimal conditions. The proposed method was successfully applied for the selective determination of VK 3 in poultry drug samples. All results indicated that the proposed imprinted electrode will provide a promising mimetic sensing platform for the determination of VK 3 in animal feedstuffs, livestock products and veterinary drugs. [ABSTRACT FROM AUTHOR]

We experimentally study two-body Coulomb explosions of CO2, O2, and CH3Cl molecules in intense femtosecond laser pulses. We observe an obvious variation in the ionic angular distribution of the fragments with respect to the kinetic energy releases (KERs). Using a classical model based on ab initio potential energy curves, we find that the dependence of the ionic angular distribution on the KER is relevant to the fact that the accurate potential energy deviates significantly from the value determined by applying the Coulomb interaction approximation at a relatively small internuclear distance of the molecule. We show that the KER-dependent ionic angular distribution provides an effective way to determine the critical internuclear distance at which the Coulomb interaction approximation holds or breaks down without relying on the knowledge of the accurate potential energy curves. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) dotted S-doped carbon (AuNPs/S-C) nanoflakes were synthesized via a facial and simple approach. Typical synthesis route involves the formation of gold nanoparticles/poly(3,4-ethylenedioxythiophene) (AuNPs/PEDOT) and a subsequent calcination process. Many techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) were used to characterize their morphology, structures and compositions. Results indicated that AuNPs with an average size of 5 nm were uniformly dotted on/into the S-C nanoflakes. The AuNPs/S-C/nafion was utilized as a new electrode material for simultaneously electrochemical determination of Cu (II) and Hg (II) using differential pulse anodic stripping voltammetry (DPASV) technique. Benefiting from the efficient metal-complexing ability and electrocatalytic activity of S-C and the good conductivity of AuNPs, the modified electrode exhibited enhanced electrochemical performance compared with bare glassy carbon electrode. Under optimal conditions, the peak currents displayed linear response to the concentrations of Cu (II) and Hg (II) ranges from 0.64 to 63.55 μg/L and 4.01 to 300.89 μg/L, with detection limits of 0.19 μg/L and 1.40 μg/L (S/N = 3), respectively. The modified electrode was also applied for the determination of Cu (II) and Hg (II) in lake water samples with good results. [ABSTRACT FROM AUTHOR]

We designed a new fluorescent conjugated polymer thin film sensor via direct electropolymerization of the corresponding electroactive monomer M onto the surface of ITO electrode, and the thin film-Fe 3+ complex was used for the highly-selective detection of fluoride ion (F − ) in water environmental samples. The as-obtained thin film could effectively detect Fe 3+ as a selective turn-off fluorescent sensor, and exhibited outstanding reversibility. This film in the presence of Fe 3+ showed a highly selective turn-on response toward F − over other anions with a 5-fold enhancement in the fluorescence intensity. F − with a relatively wide concentration range from 10 μM to 3 mM could be determined in a rather simple and sensitive manner with a detection limit of 6.78 μM (0.128 ppm). Analytical applicability of the film-Fe 3+ complex for determining the levels of F − in environmental water samples has been successfully demonstrated by fluorescent analysis with satisfactory results. This strategy will provide a new approach for the facile design of new molecular sensing devices and practical application in environments. [ABSTRACT FROM AUTHOR]

Similarly to polyanilines, polypyrroles, and polythiophenes, polyindoles belonging to the fused-ring family have emerged in the past several decades as promising materials due to their unique physical and electrochemical properties. To date, polyindoles have been studied in over 200 scientific publications. These studies revealed that the materials based on polyindoles could have an important influence on electrochromic devices, sensors, catalysis and electro-catalysis, anticorrosion, diodes, supercapacitors, batteries, and biology-related applications. The aim of this review is to provide an overview of the development of polyindoles with regard to synthesis, polymerization mechanisms, copolymers, composites, properties, and applications, and reflect on the related existing challenges and make notes on future perspectives. [ABSTRACT FROM PUBLISHER]

In this review, PEDOT--PSS is mainly a commercially available PEDOT--PSS, which is a water-dispersible form of the intrinsically conducting PEDOT doped with the water-soluble PSS, including its derivatives, copolymers, analogs (PEDOT:PSSs), even their composites via the chemical or physical modification toward the structure of PEDOT and/or PSS. First, we will focus on discussing the scientific importance of PEDOT--PSS in conjunction with its extraordinary properties and broad multidisciplinary applications in organic/polymeric electronics and optoelectronics from the viewpoint of the historical development and the promising application of representative ECPs. Subsequently, versatile film-forming techniques for the preparation of PEDOT--PSS film electrode were described in details, including common coating approaches and printing techniques, and many emerging preparative methods were mentioned. Then challenges (e.g., conductivity, stability in Water, adhesion to substrate electrode) of PEDOT--PSS film electrode for devices under the high humidity/watery circumstances, especially electrochemical devices are discussed. Fourth, we take PEDOT--PSS film electrode for a relatively new application in sensors as an example, mainly summarized advances in the development of various sensors based on PEDOT--PSSs and their composites in combination with its preparative methods and extraordinary properties. Finally, we give the outlook of PEDOT--PSS for possible applications with the emphasis on PEDOT--PSS film electrode for electrochemical devices, including sensors. [ABSTRACT FROM AUTHOR]

Free-standing conductive films are important for the application in organic electronics. However, PEDOT as one of the most promising CPs is difficult to be prepared into free-standing paper. Herein, a novel EDOT derivative, 1,6-bis((2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methoxy)hexane (BEDTH), was synthesized and easily electrodeposited into free-standing flexible conducting poly(1,6-bis((2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methoxy)hexane) (PBEDTH) in CH 2 Cl 2 containing 0.1 M Bu 4 NBF 4 . The free-standing PBEDTH films with the conductivity of 0.11 S cm −1 were characterized by FT-IR, UV–vis, SEM, TG, dynamic mechanical analysis and electrochemical method, respectively. Electrochemical results indicated that the specific capacitance of PBEDTH film was 40.8 F g −1 at the current density of 0.5 A g −1 in ionic liquid BmimBF 4 with the cycling capacitance retention of 86.7% after 5000 cycles. Additionally, the thermoelectric property of free-standing flexible PBEDTH film was also studied, showing the Seebeck coefficient was 37.2 μV K −1 and the power factor was 0.015 μW K −2 m −1 at 300 K. Although the capacitive and thermoelectric performance is not satisfactory, the free-standing flexible PBEDTH films will still be promising in the areas of energies and sensors in the true sense. [ABSTRACT FROM AUTHOR]

In this paper, poly[poly( N-vinyl-carbazole)] (PPVK) films electrodeposited in tetrahydrofuran (THF) containing 12 % boron trifluoride diethyl etherate (BFEE) were studied as electrode active material for supercapacitors. The morphology and thermal property were characterized by SEM, atomic force microscopy (AFM), and thermogravimetry (TG), respectively. The electrochemical capacitive behaviors of the PPVK films were also investigated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The electrochemical results showed that the specific capacitance of PPVK films in CHCN solution was about 126 mF cm at 1.5 mA cm and the capacitance retention was only 14.4 % after 1000 cycles. It was exciting to improve the specific capacitance up to 169.3 mF cm at 1.5 mA cm and to make the cyclic stability increase to 81.8 % capacitance retention after 5000 cycles when the equivalent BFEE was added into the CHCN solution containing 0.05 M BuNBF electrolyte. These results clearly demonstrated that BFEE was an efficient promoter for the enhancement of the capacitance performance of PPVK films. Therefore, with the help of BFEE electrolyte, the PPVK films have potential application as capacitive materials in high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Many researches involving in the solvent treatment of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) have been carried out for enhancing the electric conductivity. Herein, the capacitive performance of commercial PEDOT:PSS (trade name: PH1000) treated by NMP, EG and DMSO solvents were studied, including their conductivity, morphology, surface roughness and surface composition. Compared with pristine PH1000 film, the electrochemical active windows of the solvent-treated PH1000 films were negatively shifted to about −0.8 V from 0 V, and more excitedly, the operating voltage of all-solid-state symmetrical supercapacitors based on the treated PH1000 films could enhance up to 1.8 V from about 1.2 V with an excellent stability during 2500 charge/discharge cycles. Moreover, the effects of the three solvents on the capacitive performance of devices were compared in detail, which discovered that the device built with DMSO-treated PH1000 showed superior capacitance behaviors. [ABSTRACT FROM AUTHOR]

Herein, an electrochemical sensor was developed for detecting heavy metal ions by using a carboimidazole grafted reduced graphene oxide (reduced graphene oxide-NH-carboimidazole, abbreviated as RGO-NH-Ci) modified electrode. The morphology of RGO-NH-Ci material was characterized by scanning electron microscopy (SEM). The electrochemical behaviors of the RGO-NH-Ci modified electrode toward heavy metal ions, including Hg 2 + and Pb 2 + , were investigated with differential pulse anodic stripping voltammetry (DPASV). Compared with pure reduced graphene oxide (RGO), RGO-NH-Ci modified electrode showed improved analytical performance in detecting the two metal ions owing to the strong complexing capacity of Ci and the presence of the amino groups. The detection limits were estimated to be 0.2 nM and 3.0 nM for Hg 2 + and Pb 2 + , respectively, under the optimized conditions. The developed method was also employed to detect the Hg 2 + and Pb 2 + in real water samples, and satisfactory results were obtained. [ABSTRACT FROM AUTHOR]

Abstracts Development of selective methods for the detection of mercury (Hg 2+ ) has received tremendous attention in modern chemical research due to its health hazard and persistence in environment. In this paper, the electrochemical determination of Hg 2+ at trace level based on poly(3,4-ethylenedioxythiophene) nanorods/graphene oxide nanocomposite modified glassy carbon electrode (PEDOT/GO/GCE) is reported. PEDOT/GO nanocomposite has been proposed via a simple liquid–liquid interfacial polymerization approach. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) were employed to characterize the morphology and structure of the as-prepared PEDOT/GO. The results revealed that PEDOT with a nanorods-like structure anchored on the surface of GO nanosheets, which could enhance the electro-active sites of the nanocomposite. Differential pulse stripping voltammetry (DPSV) was applied to determine low concentrations of Hg 2+ on PEDOT/GO/GCE. Experimental conditions, including accumulation time, pH values and deposition potential were optimized. In optimal conditions, a good linear relationship was found between peak currents and the concentration of Hg 2+ in 10.0 nM-3.0 μM range. The detection limit was estimated to be 2.78 nM at a signal-to-noise ratio of 3. Finally, the applicability for Hg 2+ determination in tap water samples was successfully demonstrated. [ABSTRACT FROM AUTHOR]

Carbon/ceramic nanocomposites have been considered as ideal candidates for electromagnetic interference shielding (EMI) applications in harsh environments. However, the conventional fabrication methods of carbon/ceramic composites are often complicated, costly and time-consuming. Herein, by applying a DC electric field during hot pressing sintering, we realized the direct growth of graphene-like carbon nanosheets (GCNs) in zirconia ceramics during sintering, achieving in situ fabrication of GCNs/zirconia nanocomposites with both high EMI shielding effectiveness (>40 dB) and mechanical strength (>1000 MPa) in one step. In particular, we found that applying a DC electric field could significantly enhance the carburization during sintering, and GCNs are in situ formed at zirconia grain boundaries. When the initial electric field is constant, the amount of in situ formed GCNs could be controlled by simply adjusting the current density, resulting in the tunable electrical conductivity. These findings will provide new opportunities for both experimental and theoretical studies on carbon/ceramic EMI shielding materials and the DC electric field-assisted sintering technique. [Display omitted] • In situ growth of graphene-like carbon nanosheets (GCNs) in oxide ceramic is achieved under DC field. • The amount of GCNs can be controlled by adjusting current density, resulting in the tunable conductivity. • The nanocomposites exhibit superior electromagnetic interference shielding performance and mechanical strength. [ABSTRACT FROM AUTHOR]

In the past few decades, trap emission was always believed hardly manipulated to luminescent quantum dots (QDs). Actually, not all trap emissions are useless. This work shows that the interface between MnSe dopant and ZnSe host could be used for manipulating irradiative defects with a controllable manner. This study focuses on three basic challenges for manipulating interface defects, including (i) how to introduce irradiative defects at the dopant-host interface, (ii) how to control the intensity of the interface trap emission, and (iii) how to tune QD emission color via the interface trap emission. Finally, this study shows the application of dopant-host interface defects in ratiometric optical thermometry. [ABSTRACT FROM AUTHOR]

This paper demonstrates that Au–PEDOT/reduced graphene oxide nanocomposite (Au–PEDOT/rGO) can be rapidly synthesized through a facile, cost-effective one-pot method with chloroauric acid as the oxidant and NaBH 4 as the reductant successively. The morphology, composition and structure of the obtained composites were confirmed by SEM, TEM, XRD, Raman and XPS characterizations. The Au–PEDOT/rGO modified glassy carbon electrode (GCE) showed significantly improved charge transfer efficiency and high electrocatalytic activity toward caffeic acid (CA) oxidation as compared to bare GCE and Au-PEDOT modified electrode. Under optimized conditions, the Au–PEDOT/rGO constructed sensors exhibited a wide linear range of 0.01–46 μM with the correlation coefficient of 0.9926 and a detection limit as low as 0.004 μM for the detection of CA. To validate its possible application, the present sensor was also illustrated with satisfactory anti-interference performance, high reproducibility and sensitivity for the determination of CA in red wine sample. The prepared Au–PEDOT/rGO nanocomposite is a promising electrode material for the determination of CA in red wines or other CA-containing food and beverage. [ABSTRACT FROM AUTHOR]

Cu nanoparticle/graphene oxide/single walled carbon nanotube (CuNP/GO/SWCNT) composites were prepared by a facile electrodeposition method and used for constructing nonenzymatic glucose sensor. Scanning electron microscopy (SEM) and Raman spectroscopy were employed to characterize the morphology and structures of the samples. The electrocatalytic performance of CuNP/GO/SWCNT composites towards glucose oxidation was studied by cyclic voltammetry (CV) and current–time measurements. Electrochemical results indicated that CuNP/GO/SWCNT electrode exhibited a higher electrocatalytic activity towards the oxidation of glucose than CuNP, CuNP/GO and CuNP/SWCNT electrodes. This was because the GO/SWCNT composite as substrate material not only possessed excellent conductivity, but also provided large surface area for the high loading of the CuNPs. Meanwhile, the good dispersibility, independent and multi-layer structure of CuNP, could enhance the charge-transport properties, and afford more active sites for the catalytic oxidation of glucose. Under the optimized conditions, the sensor showed a high sensitivity of up to 930.07 μA mM − 1 cm − 2 , with a wide linear range of 1 μM to 4.538 mM and a low detection limit of 0.34 μM (S/N = 3). It also exhibited excellent stability, reproducibility, selectivity, and reliable measurement in real human blood samples. All of these excellent properties made the CuNP/GO/SWCNT composite material promising for the development of effective nonenzymatic glucose sensors. [ABSTRACT FROM AUTHOR]

A fluorescent conjugated polymer thin film sensor via the electropolymerization for fluorescent detection of Fe 3+ in aqueous solution was successfully fabricated using a poly(5-cyanoindole) (P5CI), which was electrochemically prepared in the mixed electrolyte of boron trifluoride diethyl etherate, diethyl ether and tetrabutylammonium tetrafluoroborate on ITO electrodes by successive cyclic voltammetry. The thickness of the electropolymerized P5CI thin film could be precisely controlled by optimizing scan cycles and scan rates. The as-obtained fluorescent P5CI thin film sensor could effectively recognize Fe 3+ with outstanding sensitivity, selectivity, reversibility and reproducibility over other commonly coexistent metal ions and anions, and realize the quantitative determination of Fe 3+ in a linear range of 0.2 μM–0.5 mM with a detection limit of 0.897 ppb. The reversibility and reproducibility of P5CI thin film sensor were assessed. Satisfactory results indicated that fluorescent conjugated polymers via the electropolymerization provided a promising candidate for fluorescent thin film sensor. [ABSTRACT FROM AUTHOR]

Toxic heavy-metal ions are well known to be severely harmful to human health. Therefore, the development of fast and sensitive methods for their detection has drawn a great attention in recent years. Herein, a sensitive electrochemical platform for the simultaneous determination of Cd 2 + , Pb 2 + , Cu 2 + , and Hg 2 + has been constructed based on N-doped graphene (NG) modified electrode using differential pulse stripping voltammetry (DPSV). NG was synthesized by a facile, efficient and green electrochemical method. The structure and composition of NG were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron microscopy (XPS) techniques, chronocoulometry and N 2 adsorption–desorption measurements. The NG modified electrode showed excellent catalytic activity for selective detection of Cd 2 + , Pb 2 + , Cu 2 + , and Hg 2 + due to its particular structure and unique electronic properties. Under optimal conditions, the limits of detection were estimated to be 0.05 μM for Cd 2 + and Hg 2 + , 0.005 μM for Pb 2 + and Cu 2 + , respectively. Finally, the method was applied to the simultaneous detection of trace metal ions in the tap water samples. [ABSTRACT FROM AUTHOR]

Electrochemically reduced graphene oxide (ERGO) based voltammetric sensors have drawn considerable attentions due to their simple preparation process and outstanding electrochemical properties. While quite a lot of work suffers from problems in terms of sensitivity and cycling stability. Here, we demonstrate that the reduction extent of ERGO displays a crucial role in enhancing sensitivity and preventing electrode fouling. To illustrate this, partially reduced and relatively complete reduced ERGO films were prepared via the electrochemical method. The reduction extent was controlled by performing cyclic voltammetry with varieties of reduction cycle numbers. Results indicated that partially reduced ERGO film with 5 reduction cycle numbers (ERGO 5 ) showed the highest sensitivity towards electrochemical oxidation of isoniazid (INZ) among all the ERGO films with different reduction extents, and acquired better electrode stability as compared with ERGO 15 . Under the optimal conditions, the peak currents on ERGO 5 modified electrode increased linearly with the concentrations of INZ in the range of 0.09–100 μM. The detection limit of INZ reached 15 nM (S/N = 3). The present work has a guidance meaning in developing ERGO based sensors for detecting other electroactive analytes. [ABSTRACT FROM AUTHOR]

Nanostructured poly(3,4-ethylenedioxythiophene)/β-cyclodextrin (PEDOT/β-CD) was prepared by the oxidation of EDOT with FeCl 3 using β-CD as substrate. The as-synthesized nanocomposites were characterized by scanning electronic microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and electrochemical impedance spectroscopy (EIS). It was found PEDOT/β-CD clusters were uniformly distributed, and hold an enhanced surface-to-volume ratio. The electrocatalytic performance of the nanostructured PEDOT/β-CD toward hyperoside and shikonin was investigated, which revealed that PEDOT/β-CD performed a better electrocatalytic activity than pure PEDOT. Thus, PEDOT/β-CD clusters were proposed as electrochemical sensing platform to detect hyperoside and shikonin. This simple PEDOT/β-CD complex demonstrated very sensitive and selective hyperoside and shikonin detection capability, as well as high reproducibility and stability. [ABSTRACT FROM AUTHOR]

Maleic hydrazide (MH) was successfully detected using a novel electrochemical sensor based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)-carboxymethyl cellulose-single-walled carbon nanotubes modified glassy carbon electrode (PEDOT:PSS-CMC-SWCNT/GCE). A commercially available aqueous PEDOT:PSS dispersion with good processability and conductivity was used as electrode modified substrate material, while a water-soluble and adhesive CMC was selected as both binder and dopant to improve the long-term electrode stability in water of the PEDOT:PSS composite film and obtain synergistically enhanced electrocatalytic ability for analytes. A commercially available SWCNT dispersion with good processability, enhanced electrocatalytic ability and large rough surface area was selected as enhancer to improve the sensing performance of PEDOT:PSS composite electrode. The properties of the prepared composite film and its electrode were characterized and employed for the electrochemical detection of MH. The electrochemical behaviors of MH, optimum experimental parameters, and the performance of sensing electrode were investigated. The fabricated PEDOT:PSS-CMC-SWCNT/GCE accelerated electron transfer, enhanced synergistically electrocatalytic ability toward MH oxidation and displayed excellent sensing performance such as wide linear range (0.8–51 μM) and a low limit of detection (0.1 μM) and good sensing stability. [ABSTRACT FROM AUTHOR]

The effects of various DC electric fields (0–167 V/cm) on liquid-phase hot pressing of Si 3 N 4 ceramics were investigated. The application of a DC field promoted the α→β phase transformation of Si 3 N 4 near the cathode while inhibiting it near the anode. As a result, the Si 3 N 4 ceramics with continuously graded microstructures and mechanical properties were in situ fabricated from a homogeneous raw powder. Although the DC field-driven migration of Mg2+ and Y3+ ions was recorded, the graded phase transformation phenomenon was linked to the Peltier effect, which led to additional heating at the cathode and cooling at the anode. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) composite film with superior stability in water, adhesion and flexibility, which is very critical for maintaining the long-term stability in water of the PEDOT:PSS film electrode, was easily prepared by introducing a water-soluble, anionic, non-toxic and biocompatible biopolymer (sodium carboxymethyl cellulose, Na-CMC) into a commercially available aqueous dispersion of the conducting polymer (PEDOT:PSS dispersion). The high conducting PEDOT:PSS-CMC film exhibited good flexibility and long-term stability in water after being soaked in water for 35 days. The high performance film electrode with excellent adhesion, long-term electrode stability in water (retaining almost 99.4% of its original activity for 105 days), and electrochemical properties was prepared facilely by drop-coating, and displayed good synergistically enhanced electrocatalytic ability towards the anodic oxidation of harmful substances and nutritional ingredients in edible agro-products, which were employed for its application in electrochemical sensors. The simultaneous or individual detection of maleic hydrazide, salicylic acid, nitrite, sunset yellow, and tryptophan was successfully realized using PEDOT:PSS-CMC/GCE, and exhibited superior sensing stability. All satisfactory results indicated that the introduction of CMC into PEDOT:PSS could improve the flexibility, adhesion, long-term electrode stability in water and electrocatalytic ability, which would provide a promising platform for the application in electrochemical fields of the high performance film electrode, especially the application in electrochemical sensors. [ABSTRACT FROM AUTHOR]

Hierarchical nanocomposites of poly(3,4-ethylenedioxythiophene) nanorods array on graphene oxide nanosheets (PEDOT/GO) were synthesized via a liquid–liquid interfacial polymerization method. The synthesized composites were characterized by using Fourier transform infrared (FTIR) and Raman spectroscopic studies, and their morphology was analyzed by transmission electron microscopy (TEM). Characterization and surface morphology results indicated that PEDOT with a nanorods-like structure successfully anchored on the surface of GO sheets, which could enhance the electro-active sites of the nanocomposites. Then the obtained PEDOT/GO nanocomposites were utilized to modify glassy carbon electrode and designed for the trace level sensing of rutin. Electrochemical results revealed that the PEDOT/GO nanocomposites modified electrode exhibited larger oxidation peak currents of rutin than pure PEDOT and GO owing to the synergistic effect of GO and PEDOT nanorods. Under optimized conditions, the anodic peak current was linear to the concentration of rutin in the range from 0.004 to 60 μM with the detection limit of 0.00125 μM. To further validate its possible application, the proposed method was successfully used for the determination of rutin in pharmaceutical formulations with satisfactory results. [ABSTRACT FROM AUTHOR]

Theasymmetrical sulfur analog of 3,4-ethylenedioxythiophene (EDOT),thieno[3,4-b]-1,4-oxathiane (EOTT), was synthesized,and its electropolymerization was comparatively investigated by employingdifferent solvent–electrolyte systems (room temperature ionicliquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6), CH2Cl2–Bu4NPF6, and CH2Cl2–BmimPF6). Further, the effect of solvents and supporting electrolytes onthe structure, morphology, electrochemical, electronic, and opticalproperties and electrochromic performance of the obtained poly(thieno[3,4-b]-1,4-oxathiane) (PEOTT) films were minutely studied. PEOTTfilm with a band gap (Eg) of about 1.6eV could be facilely electrodeposited in all the solvent-electrolytesand displayed excellent electroactivity, outstanding redox stabilityin a wide potential window, and improved thermal stability. Cyclicvoltammetry showed that EOTT could be electropolymerized at a loweroxidation potential in BmimPF6(∼1.0 V vs Ag/AgCl)due to several advantanges of RTIL BmimPF6itself, suchas high intrinsic conductivity and mild chemical conditions, etc.,and the resulting PEOTT film exhibited compact morphology with betterelectroactivity and stability and higher electrical conductivity.On the other hand, PEOTT films from all the sovent-electrolytes alsoshowed the electrochromic nature by color changing from gray blueto green, and further kinetic studies revealed that PEOTT had decentcontrast ratios (36%), higher coloration efficiencies (212 cm2/C in BmimPF6), low switching voltages, moderateresponse time (1.2 s), excellent stability, and color persistence.From these results, PEOTT provides more plentiful electrochromic colorsand holds promise for display applications. [ABSTRACT FROM AUTHOR]

Most recently, conjugated oligo-/polymers containing furan have regained attention due to their unique properties and promising application in organic electronics. Herein, to acquire a thorough fundamental understanding of the electrosynthesis and properties of furan-EDOT copolymers from different initial monomers, the synthesis and electropolymerization performances of furan-EDOT monomers, namely 5-(furan-2-yl)-2,3-dihydrothieno[3,4- b ][1,4]dioxin (EDOT-Fu), 5,7-di(furan-2-yl)-2,3-dihydrothieno[3,4- b ][1,4]dioxin (Fu-EDOT-Fu), and 2,5-bis(2,3-dihydrothieno[3,4- b ][1,4]dioxin-5-yl)furan (EDOT-Fu-EDOT), were comprehensively reported and the effect of different monomers on the structure and properties of the resulting polymers obtained under optimized electrical conditions were systematically evaluated. The monomers exhibit good blue-green photoluminescence with quantum yields ranging from 0.5 to 40%, which may be used as building blocks for rational design of fluorescent conjugated systems. The onset oxidation potential ranged from 0.78 V-0.45 V with the incorporation of EDOT unit in monomer chain, thus leading to the facile electrodeposition of free-standing films with improved optoelectronic properties in comparison with polyfuran. The obtained copolymers featured the advantageous combination of polyfuran and PEDOT, such as higher fluorescence and better planarity of polyfuran, transparency and excellent redox stability of PEDOT. Structure characterization and properties of the as-formed copolymer films from different initiative monomers, including FT-IR, UV-vis, TG, fluorescence, surface morphology and electrochromic properties, etc., were systematically investigated and comparatively discussed. [ABSTRACT FROM AUTHOR]

ABSTRACT 2-((2,3-Dihydrothieno[3,4- b]dioxin-2-yl)methoxy)methyl oxirane (EDOT-MO) was successfully synthesized by the reaction of epichlorohydrin with hydroxymethylated-3,4-ethylenedioxylthiophene (EDOT-MeOH), which was synthesized via a simple four-step sequence. Poly(hydroxymethylated-3,4-ethylenedioxylthiophene) (PEDOT-MeOH) and poly(2-((2,3-dihydrothieno[3,4- b]dioxin-2-yl)methoxy)methyl oxirane) (PEDOT-MO) were electrosynthesized through electropolymerization of EDOT-MeOH and EDOT-MO, respectively. Structural, electrochemical, optical, and thermal properties of as-formed polymers were investigated by FTIR, cyclic voltammetry, UV-vis, and thermogravimetry. Spectroelectrochemistry studies demonstrated that PEDOT-MeOH and PEDOT-MO could be reversibly oxidized and reduced accompany with obvious color changes. Further kinetic studies demonstrated that the introduction of hydroxymethyl or ethylene oxide group significantly improved electrochromic properties of 3,4-ethylenedioxythiophene (PEDOT) and resulted in high contrast ratios (57.3% at 585 nm) and coloration efficiencies (338.5 cm2 C−1), low switching voltages, and fast response time. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1989-1999 [ABSTRACT FROM AUTHOR]

Abstract: The water-stability and adhesion are one of major problems of PEDOT:PSS film electrode nowadays due to easy swelling, disintegration, cracking-off, and falling of PEDOT:PSS film itself in water. The synergetic or complementary effects between organic and inorganic components can improve properties or performances of composite materials which have recently gained extensive interest in many fields. Two highly water-stable poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) composite materials based on an environmentally friendly polymer and the most studied and promising novel carbon nanomaterials available today are successfully prepared by the incorporation of the poly(vinyl alcohol) (PVA) and multiwalled carbon nanotubes (MWCNTs) or carboxylic group functionalized graphene (GR-COOH) into a commercially available aqueous dispersion of PEDOT:PSS. The two as-prepared highly water-stable PEDOT:PSS–PVA–novel carbon nanomaterials composite film electrodes with excellent adhesion properties are employed for the electrochemical determination of ternary mixture containing epinephrine, uric acid and tryptophan or niclosamide using linear sweep voltammetrys. PVA, a binding agent with adhesive properties, high tensile strength and good flexibility, can enhance the adhesion and binding force between PEDOT:PSS film and electrode interface, and improve swelling and degradation of PEDOT:PSS film in water. MWCNTs and GR-COOH with excellent electrical, optical, thermal and mechanical properties can enhance the electrocatalytic performance and sensing stability of PEDOT:PSS film electrodes. Especially, GR-COOH improves flexibility of PEDOT:PSS–PVA film. The fabricated film electrodes with superior water-stability and adhesion properties exhibit excellent electrocatalytic activity towards sensing application. Satisfactory results indicate that the prepared PEDOT:PSS organic/inorganic composites materials can provide a promising platform for the potential application of electrochemical modified electrode. [Copyright &y& Elsevier]

The preparation process of MXene@PDA/NH 2 -MWCNTs modified electrode and its application for AAP determination. [Display omitted] • Hierarchical MXene@PDA/NH 2 -MWCNTs was prepared. • PDA enhances the interfacial bonding stability between MXene and NH 2 -MWCNTs. • MXene@PDA/NH 2 -MWCNTs was utilized as a platform for electrochemical sensing of AAP. • MXene@PDA/NH 2 -MWCNTs showed ultra-sensitive detection towards AAP. • The method was successfully applied for analysis of AAP in real samples. MXene/MWCNTs nanohybrid has been deemed as ideal electrode material owing to its unique structure, and physical and chemical properties. However, the bonding between MXene and MWCNTs reported in most literatures mainly depends on the π-π, hydrogen bonds, and electrostatic interaction, which limit the mechanical stability of the materials. To address this issue, herein, a facile approach was developed to in situ cross-link amino functionalized multi-carbon nanotubes on polydopamine functionalized MXene (MXene@PDA/NH 2 -MWCNTs). The NH 2 -MWCNTs can be well and firmly distributed on the MXene@PDA via Michael addition reaction. The resultant MXene@PDA/NH 2 -MWCNTs composite displays hierarchical structure, large specific surface area, good conductivity and electrocatalytic ability. Attributing to these characters, the composite modified electrode presents prominent sensing performance toward the determination of acetaminophen (AAP) with good linear response from 5.0 nM to 10.0 μM and 10.0 μM to 60.0 μM, along with a low detection limit of 1.0 nM (S/N = 3). Furthermore, the MXene@PDA/NH 2 -MWCNTs electrode shows acceptable reproducibility, good selectivity and excellent stability. This method is also employed to detect AAP in the actual samples with approving results. [ABSTRACT FROM AUTHOR]

Abstract: A commercially available aqueous poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (PEDOT:PSS) as the immobilization matrix of biologically active species for the development of sensing and biosensing devices has not been widely reported due to its swelling and disintegration in aqueous solution. In this paper, a lowly swelling and disintegrating PEDOT:PSS composite films as the electrochemical biosensing platform was successfully developed by the incorporation of the biocompatible binding agent and common ionic liquid. Nafion was selected as a binding agent, mainly because Nafion could provide the biocompatible environment for biologically active species, improve the adhesion and binding force between films and electrode interface, and prevent peeling off of both enzyme molecules and films. 1-Butyl-3-methylimidazolium tetrafluoroborate, one of common ionic liquids, was used for the secondary dopant and enhancer to improve the water-resistance and electrochemical properties of PEDOT:PSS films. Ascorbate oxidase was used as a mode for the development and application of the electrochemical biosensor. The prepared PEDOT:PSS composite modified electrode exhibited the pronounced water-stability. Moreover, the fabricated biosensor displayed an excellent bioelectrocatalytic activity to the oxidation of vitamin C, fast current response, high sensitivity, wide linear range, low detection limit, high bioaffinity and specificity, and satisfactory results in practical application, indicating that the fabricated biosensor has good electrochemical biosensing performance. Meanwhile, the excellent water-stability, repeatability, reproducibility, storage stability, and electrochemical biosensing performance also make PEDOT:PSS composite modified matrix an interesting candidate for the sensing and biosensing application in the near future. [Copyright &y& Elsevier]

Abstract: This mini-review presents the progress of poly(3,4-ethylenedioxythiophene) (PEDOT)-based thermoelectric (TE) materials having been made in recent years. Systematic research on the TE properties of PEDOT has been carried out since 2008, and then attracted more and more attentions. For PEDOT-based materials, a ZT of 10−1 can be easily obtained nowadays. Considering the advanced techniques for bulk material processing and intensive concerns on PEDOT, a ZT ∼100 may be possible for PEDOT-based TE materials in the near future. However, this TE performance level (10−1–100) may be enough for military and niche applications, since other inherent attributes of PEDOT such as weight, size, and flexibility may be of greater importance. In this paper, we reviewed various materials based on PEDOT in nanoscales, mixtures, and composites and summarized their TE properties, which might facilitate the future TE research of PEDOT. [Copyright &y& Elsevier]

Abstract: The goal of this preliminary study was to produce a promising alternative tool for the direct, rapid and specific determination of vitamin C (VC) content in real samples of different agricultural crops without pre-treatment. For this purpose, a VC electrochemical biosensor based on one-step immobilization of ascorbate oxidase in the biocompatible conducting poly(3,4-ethylenedioxythiophene)-lauroylsarcosinate (PEDOT-SL) film was facilely developed. AO molecules were incorporated into the resulting PEDOT-SL film by using a co-electrodeposition technique under optimum conditions. The sodium N-lauroylsarcosinate provided a good biocompatible environment for biologically-active macromolecules AO. The electrochemical characterization and scanning electron microscopy indicated that AO molecules were successfully immobilized in this PEDOT-SL film. The parameters of the biosensor such as the film thickness, working potential, pH, concentration of PBS, and temperature were optimized. The biosensor displayed an excellent bioelectrocatalytic activity to the oxidation of VC and could successfully detect VC in the concentration range of 0.002–14mM. The biosensor also exhibited a high sensitivity of 80.4mAM−1 cm−2, a fast response time of 15s, a low working potential of 0.2V, a low detection limit of 0.464μM. In addition, high bioaffinity, bioactivity, stability and specificity of this biosensor were also evaluated. The excellent performance of the prepared biosensor and good results of the VC determination in commercial juices and vegetable crops indicated that the as-fabricated biosensor will be a good candidate for the detection and analysis of VC in agricultural crops. [Copyright &y& Elsevier]

Abstract: Electrocatalytic activities of the monometallic Pt and bimetallic Pt–Ru nanoparticles dispersed onto polycarbazole (PCZ) films obtained by the electropolymerization on glassy carbon electrode (GC) (i.e., Pt/PCZ/GC, Pt–Ru/PCZ/GC) towards formic acid oxidation have been investigated using cyclic voltammetry and chronoamperometry methods. As-formed electrodes are characterized by SEM, EDX and electrochemical analysis. Relative to Pt and Pt–Ru deposited on the bare GC (i.e., Pt/GC and Pt–Ru/GC), Pt/PCZ/GC and Pt–Ru/PCZ/GC, respectively, exhibit higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electrooxidation. The enhanced performance is proposed to come from the synergetic effect between metal nanoparticles (Pt, Pt–Ru) and PCZ. At the same time, the results of the stripping voltammograms of CO show that PCZ can weaken largely the adsorption strength of CO on catalysts and can make CO oxidation easier under lower potential, implying further that PCZ can be used as an efficient promoter for electrocatalytic oxidation of formic acid on Pt/PCZ and Pt–Ru/PCZ catalysts. [Copyright &y& Elsevier]

Abstract: Direct anodic oxidation of (S)-(−)-1,1′-bi-2-naphthol dimethyl ether (BNME) in CH2Cl2/CHCl3 containing boron trifluoride diethyl etherate (BFEE) as the supporting electrolyte led to facile electrodeposition of high-quality free-standing poly((S)-(−)-1,1′-bi-2-naphthol dimethyl ether) (PBNME) film on stainless steel (SS)/indium tin oxide (ITO) electrodes. As-formed PBNME films showed good electroactivity and redox stability in CH2Cl2–BFEE, BFEE, and even in concentrated sulfuric acid. Both doped and dedoped PBNME films were partly soluble in strong polar solvents, such as dimethyl sulfoxide (DMSO). Quantum chemistry calculations of BNME and FT-IR spectrum of dedoped PBNME films demonstrated that the polymerization probably occurred at 4- and 4′-positions. Optical rotation determination showed that the conformation of the monomer was maintained during the electrochemical polymerization process and the polymer exhibited greatly enhanced optical rotation value with main chain axial chirality compared with that of the monomer. Fluorescent spectral studies indicated that soluble PBNME was a good blue-light emitter with maximum emission at 415nm and fluorescence quantum yield of 0.15, while solid-state PBNME film showed its emission centered at 380nm. Furthermore, as-formed PBNME manifested favorable thermal stability and relatively high electrical conductivity of about 10−1 Scm−1 at room temperature. [Copyright &y& Elsevier]

Abstract: Poly(3,4-ethylenedioxythiophene) (PEDOT) films were synthesized electrochemically by direct anodic oxidation of 3,4-ethylenedioxythiophene (EDOT) in aqueous solution containing the environmentally–friendly amino acid-based surfactant sodium N-lauroylsarcosinate (SLS), which as a mild biosurfactant has good biocompatibility, low toxicity, good solubilization, and efficient and quick biodegradability. The moderate interactions between a neutral SLS–aqueous micellar solution and EDOT monomer led to the decreased onset oxidation potential of EDOT. PEDOT films were characterized spectroscopically using Fourier transform infrared and ultraviolet–visible techniques. PEDOT films with good thermal stability and electrical conductivity of 5Scm−1 were synthesized in neutral SLS–water micellar solutions. [Copyright &y& Elsevier]

Abstract: The electrosyntheses of poly(3-methoxythiophene) (PMOT) by direct anodic oxidation of MOT in novel ionic liquid microemulsions, BmimPF6/Tween 20/H2O, have been investigated. Among water-in-BmimPF6 (W/IL), bicontinuous (BC), and BmimPF6-in-water (IL/W) sub-regions, IL/W was found to be the most suitable medium for the electropolymerization of MOT. The use of IL/W microemulsions remarkably reduces the amount of IL, which is really expensive as electrolyte. BmimPF6 serves both as the core of IL/W microemulsions and as the supporting electrolyte and thus presents a novel microenvironment for the electropolymerization of MOT. Thus, MOT microdroplets were assembled on a bare ITO electrode and polymerized into PMOT microcups. In addition, the oxidation onset potential of MOT in IL/W microemulsions was lower than that in micellar aqueous solutions or conventional organic solvents. As-formed PMOT films obtained in IL/W microemulsions had an electrical conductivity of 3.8S/cm and could be dissolved in many conventional organic solvents, including dichloromethane, chloroform, acetonitrile, and dimethyl sulfoxide with green-light emitting property. [Copyright &y& Elsevier]