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Conducting polymer hydrogels are widely used as strain sensors in light of their distinct skin‐like softness, strain sensitivity, and environmental adaptiveness in the fields of wearable devices, soft robots, and human‐machine interface. However, the mechanical and electrical properties of existing conducting polymer hydrogels, especially fatigue‐resistance and sensing robustness during long‐term application, are unsatisfactory, which severely hamper their practical utilities. Herein, a strategy to fabricate conducting polymer hydrogels with anisotropic structures and mechanics is presented through a combined freeze‐casting and salting‐out process. The as‐fabricated conducting polymer hydrogels exhibit high fatigue threshold (>300 J m−2), low Young's modulus (≈100 kPa), as well as long‐term strain sensing robustness (over 10 000 cycles). Such superior performance enables their application as strain sensors to monitor the real‐time movement of underwater robotics. The design and fabrication strategy for conducting polymer hydrogels reported in this study may open up an enticing avenue for functional soft materials in soft electronics and robotics. [ABSTRACT FROM AUTHOR]

Strain sensors based on conducting polymer hydrogels are considered highly promising candidates for wearable electronic devices. However, existing conducting polymer hydrogels are susceptible to aging, damage, and failure, which can greatly deteriorate the sensing performance of strain sensors based on these substances and the accuracy of data collection under large deformation. Developing conductive polymer hydrogels with concurrent high sensing performance and self-healing capability is a critical yet challenging task to improve the stability and lifetime of strain sensors. Herein, we design a self-healable conducting polymer hydrogel by compositing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibers and poly(vinyl alcohol) (PVA) via both physical and chemical crosslinking. This PEDOT:PSS-PVA nanocomposite hydrogel strain sensor displays an excellent strain monitoring range (>200%), low hysteresis (<1.6%), a high gauge factor (GF = 3.18), and outstanding self-healing efficiency (>83.5%). Electronic skins based on such hydrogel strain sensors can perform the accurate monitoring of various physiological signals, including swallowing, finger bending, and knee bending. This work presents a novel conducting polymer hydrogel strain sensor demonstrating both high sensing performance and self-healability, which can satisfy broad application scenarios, such as wearable electronics, health monitoring, etc. [ABSTRACT FROM AUTHOR]

In this work, TiO2-MXene/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite was utilized as an electrode material for the sensitive electrochemical detection of baicalein. The in-situ growth of TiO2 nanoparticles on the surface of MXene nanosheets can effectively prevent their aggregation, thus presenting a significantly large specific surface area and abundant active sites. However, the partial oxidation of MXene after calcination could reduce its conductivity. To address this issue, herein, PEDOT:PSS films were introduced to disperse the TiO2-MXene materials. The uniform and dense films of PEDOT:PSS not only improved the conductivity and dispersion of TiO2-MXene but also enhanced its stability and electrocatalytic activity. With the advantages of a composite material, TiO2-MXene/PEDOT:PSS as an electrode material demonstrated excellent electrochemical sensing ability for baicalein determination, with a wide linear response ranging from 0.007 to 10.0 μM and a lower limit of detection of 2.33 nM. Furthermore, the prepared sensor displayed good repeatability, reproducibility, stability and selectivity, and presented satisfactory results for the determination of baicalein in human urine sample analysis. [ABSTRACT FROM AUTHOR]

In this paper, a simple and stable composite electrode based on intrinsically conducting polymer poly(3,4-ethylenedioxythiophene):poly(sty-renesulfonate) (PEDOT:PSS) and ion-exchange polymer Nafion, was successfully fabricated by drop-coating the blended commercially available PEDOT:PSS aqueous dispersion and Nafion solution on the surface of glassy carbon electrode (GCE). PEDOT:PSS was used as a matrix, while Nafion was employed to improve the immobilization stability of composite films and adhesion to electrode surface in comparison with PEDOT:PSS films. Cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy were utilized to characterize the properties of this composite electrode. The as-proposed composite electrode displayed good water-stability. Meanwhile, the composite electrode was applied to electrochemical sensing of dopamine, and the performance of PEDOT:PSS-Nafion composite films was evaluated. These results demonstrate that PEDOT:PSS-Nafion composites are a promising candidate of electrode modified material in electrochemical sensing and other electrocatalytic applications.

Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films are attracting famous applications in antistatic coating, energy storage and conversion, printed electronics, and biomedical fields due to their conductivity, optical transparency and flexibility. However, PEDOT:PSS has poor dispersion stability during long‐term storage and transport. Moreover, the dried PEDOT:PSS films are insoluble in any solvent and cannot be redispersed again. In comparison to bake drying, here, a feasible strategy to achieve mechanically redispersed PEDOT:PSS with the help of freeze‐drying process was reported. The redispersed PEDOT:PSS can recover not only the initial characters such as pH, chemical composition, viscosity, and particle size under similar solid contents, but also conductivity and surface morphology of treated films. In addition, the treated film exhibits self‐healing properties similar to pristine film in terms of mechanical and electrical properties. This technology enables reuse and overcomes the technical problems of PEDOT:PSS dispersion, realizing real‐time processing to meet variable applications. [ABSTRACT FROM AUTHOR]

Herein, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/silicon dioxide nanoparticles (SiO2-NPs) composite films were prepared via a simple method by direct vacuum filtration technique. The effect of SiO2-NPs contents on the thermoelectric performance of PEDOT:PSS was investigated systematically. PEDOT:PSS nanofilm without SiO2-NPs exhibited a maximum electrical conductivity of 1487 S cm−1 and a Seebeck coefficient of 17.4 µV/K. When the SiO2-NPs were introduced, the Seebeck coefficient of PEDOT:PSS/SiO2-NPs nanocomposite films increased to a peak value of 24.2 µV/K at 20 wt% SiO2-NPs, and the corresponding electrical conductivity was 1132 S/cm. Although a compromise in electrical conductivity, a large optimized power factor up to be 66.29 µW/m K2 was achieved due to the contribution of improved Seebeck coefficient. The presence of SiO2-NPs in the composite films with small-size structure and abundant grain boundaries may cause the carrier scattering and filtering effect, which accounts for the enhanced Seebeck coefficient. [ABSTRACT FROM AUTHOR]

ABSTRACT Two-dimensional (2D) WS2 nanosheets (NSs) as a promising thermoelectric (TE) material have gained great concern recently. The low electrical conductivity significantly limits its further development. Herein, we reported an effective method to enhance the TE performance of WS2 NSs by combining poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS). The restacked WS2 NSs thin film with 1T phase structure obtained by a common chemical lithium intercalation show a high Seebeck coefficient of 98 μV K−1 and a poor electrical conductivity of 12.5 S cm−1. The introduction of PEDOT:PSS with different contents obviously improve the electrical conductivity of WS2 NSs thin films. Although a declining Seebeck coefficient was observed, an optimized TE power factor of 45.2 μW m−1 k−1 was achieved for WS2/PEDOT:PSS composite thin film. Moreover, the as-prepared WS2/PEDOT:PSS thin film can be easily peeled off and transferred to other substrate leading to a more promising application. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 997-1004 [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]

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]

ABSTRACT As conventional organic solvents present inherent toxicity, deep eutectic solvents (DES) have been considered as excellent candidates due to their green characteristics. In this work, thermoelectric properties enhancement of PEDOT:PSS films is achieved by introducing DES as an additive and post-treatment reagent. Direct addition and post-treatment approaches lead to a maximum Seebeck coefficient of 29.1 μV K−1 and electrical conductivity of 620.6 S cm−1, respectively. In addition, an optimal power factor is obtained by DES post-treatment, reaching up to 24.08 μW m−1 K−2, which is approximately four orders of magnitude higher than the pure PEDOT:PSS. Assuming a thermal conductivity of 0.17 W m−1 K−1, the maximum ZT value is estimated to be 0.042 at 300 K. Further, atomic force microscopy and X-ray photoelectron spectroscopy are performed and suggest that the remarkably enhanced electrical conductivity originates from the removal of the excess insulating PSS and the phase separation between the PEDOT and PSS chains. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 885-892 [ABSTRACT FROM AUTHOR]

ABSTRACT A novel strategy via paper as an effective substrate has been introduced as a thermoelectric material in this work. Free-standing poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/paper composite films are conveniently prepared by a one-step method of directly writing PEDOT:PSS solution on paper, making the process simple, rapid, and facile. The free-standing composite films display excellent flexibility, light weight, soaking stability in water, and great potential in large-scale production. Improved thermoelectric properties are obtained in PEDOT:PSS/paper composite films, owing to the simultaneously enhanced Seebeck coefficient (30.6 μV K−1) and electrical conductivity, and a low thermal conductivity (0.16 W m−1 K−1) compared with pristine PEDOT:PSS films. The results indicate that paper as an effective substrate is suitable for the preparation of high-performance and flexible thermoelectric materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 737-742 [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel sunset yellow sensor is fabricated with MWCNT-CONH-66-UiO/PEDOT:PSS composites. • The amidation reaction of UiO-66-NH 2 converts –NH 2 into –NHCO- for protection. • This sensor performs a linear range as 0.01–70 μM and a LOD as 3.3 nM. • The sensor is successfully applied to sunset yellow detection in cake and meat. The out-of-range, overdose and illegal usage of sunset yellow azo dye in food will cause great damage to food safety and consumer health. In this work, a novel electrochemical sensing platform toward sunset yellow detection was prepared based on the amidated MWCNT-CONH-66-UiO and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). In MWCNT-CONH-66-UiO, the –NHCO- is produced by the amidation reaction between zirconium 2-amino terephthalate (UiO-66-NH 2) and carbonylated multi-walled carbon nanotubes (MWCNT-COOH), which play significant role for the enhancement of the sensing properties of MWCNT-CONH-66-UiO/PEDOT:PSS composite. PEDOT:PSS acts as a conducting film coated on MWCNT-CONH-66-UiO and alleviates the electrooxidation of –NHCO-. The large specific surface area, good conductivity, and outstanding synergistic effect of the composite trigger off prominent sensing properties of MWCNT-CONH-66-UiO/PEDOT:PSS toward sunset yellow detection with the lowest detection limit as 3.3 nM and a sensitivity as 6.6 mA mM−1 cm−2 (active area of 0.15 cm2). Additionally, this sensor shows satisfactory results for sunset yellow detection in plain cake and marinating meat via DPV in comparison to the high-performance liquid chromatography method. The research results in this work will provide technical support for the rapid and efficient detection of azo dyes in food, animal feeds, and industrial wastewater. [ABSTRACT FROM AUTHOR]

Layered WS 2 nanosheet has advantages in the application of energy devices because of its distinctive structure and high electrochemical behaviors. The fabrication of high-quality free-standing WS 2 film is anticipant and challenging in developing its flexible and miniature device. Here, using a highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as binder, flexible free-standing WS 2 /PEDOT:PSS film as miniature supercapacitors electrode materials was easily prepared by vacuum filtration method. The WS 2 /PEDOT:PSS film was characterized by scanning electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, Raman spectrum, X-ray photoelectron spectroscopy and electrochemical technology. The free-standing WS 2 /PEDOT:PSS film with conductivity of 44 S cm −1 showed a good flexibility, robustly mechanical property and high electrochemical behaviors. The flexible film can bear 300 g weight and be used as a conducting wire in a circuit. The WS 2 /PEDOT:PSS film with thickness of ~2.1 μm exhibited high areal capacitance of 86 mF cm −2 and volumetric capacitance of 411 F cm −3 at 40 mV s −1 in 1.0 M H 2 SO 4 solution. Besides, the capacitance retention could reach 107% of initial specific capacitance after 5000 charge-discharge cycles. Moreover, the flexible device based on WS 2 /PEDOT:PSS films could be assembled without any substrates and showed a volumetric capacitance of 87 F cm −3 at 10 mV s −1 and 86% capacitance retention of initial specific capacitance after 5000 cycles. These results implied the flexible free-standing WS 2 /PEDOT:PSS film has a potential application in flexible and miniature supercapacitors without any other substrates as current collectors. [ABSTRACT FROM AUTHOR]

A nanoscale organic/inorganic hybrid thin film has been fabricated with the conductive poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) and SiC nanowires (SiC-NWs) defined as PEDOT:PSS/SiC-NWs by a facile dilution-filtration method and the thermoelectric (TE) performance has been investigated systematically. It has been demonstrated that a low content of SiC-NWs (<10 wt%) can effectively enhance the Seebeck coefficient of PEDOT:PSS films by 36.6% (20.9 μV K −1 ) with maintaining a high electrical conductivity of 1550 S cm −1 . A high power factor of 67.7 μW m −1 K −2 for the PEDOT:PSS/SiC-NWs with 3.0 wt% high purity SiC-NWs ( p -SiC-NWs) was obtained and further enhanced to 128.3 μW m −1 K −2 after H 2 SO 4 post-treatment, which is two times higher than that of pre-treatment and four times higher than that of pure PEDOT:PSS (31.8 μW m −1 K −2 ). Based on the thermal conductivity measured to be 0.23 W m −1 K −1 , the maximum ZT value was achieved as high as 0.17. Finally, a flexible TE generator has been designed and fabricated by parallel connected ten legs of the as-prepared H 2 SO 4 post-treated PEDOT:PSS/ p -SiC-NWs 3 hybrid thin films. The maximum open-circuit voltage of 21.9 mV and output power of 180 nW at Δ T = 100 K were obtained, which show great potential for the flexible TE generator development. [ABSTRACT FROM AUTHOR]

Human thermal energy as permanent generation energy source have been widely utilized in thermoelectric (TE) application today, especially for wearable electronics. In this work, an intrinsically flexible palm-power TE generator based on the p -type PEDOT:PSS-based composite films has been designed and fabricated. The combination of inorganic nano-filler and chemical treatment have been proved to be an effective strategy for improving the TE performance of PEDOT:PSS. The maximum power factor of PEDOT:PSS composite with 5% content of (Ca 0.85 Ag 0.15 ) 3 Co 4 O 9 was evaluated to be 75.2 μW m −1 K −2 after H 2 SO 4 post-treatment, which was three times higher than that of pure PEDOT:PSS. The resulting film with a good mechanical flexibility still sustained its good TE performance about 96% even after being flexed for 1000 bending cycles. Based on the parallel circuit design, the palm-power TE generator was assembled by the flexible composite films and realized a low internal resistance of 1.1 Ω and an acceptable output power of 36 nW in the palm of hand. This work may open new avenues on the design and fabrication of flexible wearable electronics for energy harvesting. [ABSTRACT FROM AUTHOR]

Thermoelectric materials have been widely used in the power generation and cooling. Tellurium (Te) nanomaterial has gained great attention due to its enhanced thermoelectric performance, however, the researches are lacking of practical applications for energy harvesting. Here, a simple thermoelectric device was built with n -type and p -type Te-based (Bi 2 Te 3 and Te-PEDOT:PSS composite) nanowires (NWs) thin film as legs for the first time. Firstly, a facile solution method was used to synthesize Te and Bi 2 Te 3 NWs. A composite thin film was composed of Te NWs and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to achieve a higher thermoelectric performance and a better environmental stability. The thermoelectric thin film device, consisting of Bi 2 Te 3 NWs as n -type leg and Te-PEDOT:PSS as p -type leg, exhibits a stable output voltage of 56 mV and high output power density value of 32 μW cm −2 at temperature difference of 60 K, which is only 20% lower than that composed of commercial Bi 2 Te 3 . However, Te-based thin film device can effectively decrease its costs and be further improved to achieve a larger output voltage in the future. [ABSTRACT FROM AUTHOR]

To date, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is considered to be one of the most successful organic thermoelectric (TE) material with a figure-of-merit ( ZT ) breakthrough of 0.42 in its field. It is highly expected to achieve higher performance for real application in the near future due to its great TE potential. Numerous effective treatment methods such as pre-treatments and post-treatments on PEDOT:PSS dispersions or films by polar organic solvents, non-ionic surfactant polymers, acids or alkalis and reducing reagents have been developed to enhance its TE performance, which are randomly distributed in different literatures from 14 research groups. To facilitate further research, in this mini-review, we summarize these methods and expound the origin of TE enhancement as well as that the future efforts and strategies are suggested. We are truly expecting this mini-review can be greatly helpful for further research and pave the way for developing more efficient organic TE materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dual network PEDOT:PSS-PAAm hydrogel is developed for solar water purification. • Such hydrogel exhibits fast evaporation rate (2.15 kg m−2 h−1) and high energy efficiency (97.2%). • 30-Day continuous testing shows superior long-term stability in simulated seawater. • The purified water can meet the drinking requirements of WHO. Photothermal materials have attracted significant interests for interfacial solar steam generation towards desalination or sewage purification. However, despite recent encouraging progress, the development of long-term stable photothermal materials with high overall performance is still one of the major hurdles to realize scalable practical usage. Herein, we develop a dual network hydrogel of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and polyacrylamide (PAAm) for interfacial solar steam generation via one-step radical polymerization and chemical cross-linking of acrylamide within viscous PEDOT:PSS nanofibril dispersion. As-obtained PEDOT:PSS-PAAm hydrogel exhibits a unique combination of advantageous evaporation performances including excellent sunlight absorption (∼99.8%), fast steam generation rate (2.15 kg m-2 h-1), and high energy efficiency (∼97.2%), comparable to the state-of-the-art photothermal materials. Furthermore, the PEDOT:PSS-PAAm hydrogel also displays fascinating mechanical properties like softness (Young's modulus: 38 ∼ 86 kPa), stretchability (fracture strain: >80%), and nice mechanical stability against varying deformations, guaranteeing its potential usage in harsh practical application environment. Toward real water purification applications, such a hydrogel is demonstrated to possess excellent long-term stability with an average energy efficiency of 94.8% and anti-salt-fouling properties against 30-day continuous outdoor exposure, superior to most previously reported photothermal materials. We further demonstrate PEDOT:PSS-PAAm hydrogel-integrated solar steam generator for practical desalination and sewage purification, and the generated water can reach the WHO drinking water standards for metal cations/organic pollutants. [ABSTRACT FROM AUTHOR]

The poor conductivity of polyindole (PIn) is a major factor to limit its application in supercapacitors. To solve the problem, a simple and efficient immersion method designed to obtain a binary nanocomposite, which composed of polyindole hollow nanospheres (PIn-NS) and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). PIn-NS with diameters of 300–600 nm and shell thickness of about 50 nm were prepared by the chemical oxidative polymerization of indole in the ethanol/H 2 O miscible solution using ammonium peroxydisulfate (APS) as oxidant agent without any surfactants. The pure PIn-NS modified carbon cloth (PIn-NS/CC) shows a low specific capacitance of 110 F g −1 at 0.5 A g −1 in 1.0 M H 2 SO 4 aqueous solution. By the immersion of PIn-NS/CC in PEDOT:PSS/ethanol solution, the obtained PIn-NS/CC-PEDOT:PSS shows a large improved specific capacitance of 623 F g −1 at 0.5 A g −1 and good stability with a cycling efficiency of 84.8% after 3000 cycles. The results demonstrate that the electrochemical properties of PIn-NS can be significantly improved with the assistance of PEDOT:PSS as electrically conductive connection. In addition, the symmetric PIn-NS/CC-PEDOT:PSS//PIn-NS/CC-PEDOT:PSS supercapacitor showed a high specific capacitance of 161 F g −1 at 0.5 A g −1 and the low equivalent series resistances (ESR) of 4.4 ohm. Therefore, such binary composite is a promising material for application in the next generation high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Green DES (ChCl/urea fluid) as a novel surface treatment reagent has been proposed for improving the thermoelectric (TE) performance of PEDOT:PSS films and demonstrated satisfying effects as expected. Simultaneous increases were found in the electrical conductivity and Seebeck coefficient, which achieved further improvement by raising the treating temperature. This additional enhancement was probably attributed to that higher temperature led to decreased viscosity thus a better interaction between the DES mixture and the film surface. The maximum electrical conductivity and Seebeck coefficient were found at 120 °C, reaching 85.6 S cm −1 and 30.1 μV K −1 . Further TE improvement was obtained when DMSO was introduced to make a mixture with DES at different ratios to act as the treatment reagent, giving rise to an optimized power factor of 25.26 μW m −1 K −2 with the corresponding electrical conductivity and Seebeck coefficient being 424.2 S cm −1 and 24.4 μV K −1 , respectively. [ABSTRACT FROM AUTHOR]

Promising electrochemical sensing platforms can be constructed by two-dimensional (2D) inorganic materials, metal nanoparticles and conducting polymers (CPs) via suitable and effective composite-structural fabrication. Herein, a sandwich-structured composite film was fabricated with MXene (Ti 3 C 2 T x), PdAu nanoparticles and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). In the fabrication, PdAu nanoparticles were first loaded on the surface of MXene nanosheets by one-pot method, preventing self-stacking and improving the dispersion of MXene nanosheets. And then, the PEDOT:PSS/MXene-PdAu/PEDOT:PSS sandwich structure was obtained with PEDOT:PSS as the upper and lower layers and MXene-PdAu as the interlayer. Indeed, the upper PEDOT:PSS film can permeate between MXene-PdAu particles and contribute to the continuity of MXene nanosheets, forming a complete conducting three-dimensional framework. The formed PEDOT:PSS/MXene-PdAu/PEDOT:PSS framework exhibits promising electrochemical sensing properties towards shikonin detection with a wide range of 0.001–35 μM, a low detection limit of 0.33 nM and a high sensitivity of 5.685 μA μM−1 cm−2. Furthermore, this sensing platform performs favorable selectivity and stability. In the actual sample testing, the sensing platform was used for shikonin detection in Lithospermum erythrorhizon and performed comparable results with high-performance liquid chromatography (HPLC), indicating the promising application prospect of PEDOT:PSS/MXene-PdAu/PEDOT:PSS film for the qualitative and quantitative analysis of shikonin. Fabrication of sandwich-structural PEDOT:PSS/MXene-PdAu/PEDOT:PSS composite film achieving high sensitivity and wide linear detection range towards the quantitative analysis of shikonin. [Display omitted] • Facile construction of sandwich-structured PEDOT:PSS/MXene-PdAu/PEDOT:PSS film. • The sandwich-structural film possesses enhanced conductivity and stability. • The film performs outstanding electrochemical sensing property for shikonin detection. • The film was successfully used for shikonin detection in Lithospermum erythrorhizon. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanically robust PEDOT:PSS-PVA hydrogel is developed for solar water evaporation. • It shows a fast evaporation rate (2.84 kg m-2 h-1) and high energy efficiency (98%). • PEDOT:PSS-PVA hydrogel can be readily accessible for scalable production. • It has superior long-term stability after 60-day continuous test in simulated seawater. • The purified water can meet the drinking requirements of WHO. Solar water purification has been attracting considerable attention due to its promising desalination and purification applications to alleviate water scarcity and pollution. However, despite recent rapid progress, rational design and development of robust and highly efficient interfacial photothermal materials sufficing for large scale real usage is still a critical challenge to the science and technology of this field. Herein, we develop a mechanically robust nanocomposite hydrogel with intriguing evaporation performance by simple blending and cross-linking of poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) nanofibrils and poly(vinyl alcohol) (PVA) viscous solution. As-prepared PEDOT:PSS-PVA hydrogel exhibits an excellent light absorption ratio of ∼ 99.7% in a wide wavelength range of 250 ∼ 2500 nm and displays unprecedented high energy efficiency of ∼ 98.0% with a fast evaporation rate of ∼ 2.84 kg m-2 h-1 under one sun irradiation. A 60-day continuous test simulating the real seawater evaporation environment shows superior long-term stability of such hydrogel with an average energy efficiency of ∼ 93.3%. To harness these advantageous properties, we further demonstrate the scalable hydrogel production and fabricate a solar water evaporator equipment for seawater desalination and wastewater purification, from which the acquired water can meet the drinking requirements set by the World Health Organization. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conducting polymer PEDOT:PSS was used as an organic thermoelectric (TE) material. [•] Low PH value (acidic condition) enhances the TE performance of PEDOT:PSS. [•] High PH value (alkaline condition) decreases the TE performance of PEDOT:PSS. [•] The recovery of TE performance after a second treatment with acid was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical RuNPs/PEDOT:PSS/Ti 3 C 2 T x ternary nanocomposite was fabricated facilely. • PEDOT:PSS can enhance the dispersibility and stability of Ti 3 C 2 T x nanosheets. • Ti 3 C 2 T x can improve the stability of PEDOT:PSS in aqueous solution. • The sensing platform shows high sensitivity and stability for Sudan I detection. In our paper, a promising electrochemical sensing platform was fabricated with titanium carbide (Ti 3 C 2 T x), poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and ruthenium nanoparticles (RuNPs). First, the Shandong pancake structural PEDOT:PSS/Ti 3 C 2 T x was prepared by physical stirring. PEDOT:PSS as the dispersant was embedded into the Ti 3 C 2 T x nanosheets, increasing the degree of dispersion of the Ti 3 C 2 T x nanosheets and further improving the specific surface area of the composite material. Then, RuNPs were supported on the surface of PEDOT:PSS/Ti 3 C 2 T x to form the hierarchical ternary nanocomposite of Ru/PEDOT:PSS/Ti 3 C 2 T x. The prepared Ru/PEDOT:PSS/Ti 3 C 2 T x nanocomposite exhibited promising electrochemical sensing properties toward Sudan I detection with a wide detection range of 0.01 ∼ 100 μM and a high sensitivity of 482.43 μA mM−1 cm−2. Moreover, the Ru/PEDOT:PSS/Ti 3 C 2 T x sensing platform has been successfully applied for Sudan I detection in ketchup and chili paste, implying the promising application prospect of Ru/PEDOT:PSS/Ti 3 C 2 T x in food safety testing. [ABSTRACT FROM AUTHOR]

• A novel Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x PM sensor was prepared. • NS-Ti 3 C 2 T x was synthesized by a chemical reaction of covalent in-situ doping. • The dispersibility and continuity of NS-Ti 3 C 2 T x layers were enhanced by PEDOT:PSS. • The sensor shows high accuracy and feasibility for PM residual detection in nature. Excessive pesticide residues (e.g., parathion-methyl, PM) not only threaten human health but also cause serious environmental pollution. Herein, a palladium-magnetic iron/poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonic acid)/nitrogen and sulfur co-doped titanium carbide (Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x) composite frameworks was fabricated, hoping to provide an interesting strategy for the design of PM sensor. First, the NS-Ti 3 C 2 T x was synthesized through N and S co-doped modification of Ti 3 C 2 T x to improve its electrical properties. The hierarchical PEDOT:PSS/NS-Ti 3 C 2 T x composite, as catalytic supports of Pd-Fe 3 O 4 , was constructed with PEDOT:PSS inserting between the NS-Ti 3 C 2 T x nanolayers to enhance the dispersibility and continuity of the layers. The components and structure of composites were well identified by various characterization and analysis methods. More importantly, the Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x /GCE sensing platform indicates an outstanding electrocatalytic activity in the electro-reduction of PM with sensitivity of 517.08 μA mM−1 cm−2, linear detection range of 0.01–140 μM, limit of detection as 3.3 nM, and k s as 3.585 s−1. Moreover, this sensing platform was successfully applied to PM residue detection in vegetable, surface water and soil, showing high accuracy and promising feasibility in application. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen-vacancy WO 3 and WO 3 -CeO 2 nanowires are synthesized by hydrothermal method. • Organic-inorganic hybrid electrode is proposed including PEDOT:PSS, WO 3 -CeO 2 and PEDOT. • WO 3 -CeO 2 -based electrode shows ultrahigh capacitance of 1310 mF cm−2 at 2 mA cm−2. • ASC device shows high energy density and long-term cycling stability comparable to batteries. Although WO 3 with high theoretical capacitance has a future in the field of energy storage, its electrode processing to obtain high capacitance is still a challenge. Here, we propose an innovative electrode structure design by utilizing PEDOT and PEDOT:PSS to sequentially assemble with the oxygen vacancies-enriched WO 3 and WO 3 -CeO 2 hybrid nanowires on the glassy carbon (GC). As-prepared PEDOT:PSS/WO 3 /PEDOT/GC and PEDOT:PSS/WO 3 -CeO 2 /PEDOT/GC electrodes show high areal capacitance of 1139.6 and 1310 mF cm−2 at 2 mA cm−2, respectively, greater than 822.3 mF cm−2 of the WO 3 -PTFE-C/GC. The asymmetric supercapacitor based on PEDOT:PSS/WO 3 -CeO 2 /PEDOT and PEDOT:PSS/RuO 2 /PEDOT electrodes works at 1.6 V high working voltage, delivers an energy density of 0.61 Wh m−2 at power density of 8.22 W m−2. Therefore, the electrode structure design will be suitable to improve the capacitance performance of other low-conductivity active materials. [ABSTRACT FROM AUTHOR]

In aqueous dispersion of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), the mixture dispersion containing different proportion of polyhedral oligomeric silsesquioxanes (POSS) and dimethyl sulfoxide (DMSO) were added. These three components were physically blended to fabricate composite films for improving the mechanical properties and the water resistance of PEDOT:PSS films; a strong drawback hindering their electrical properties. The effect of the ratio of POSS compared to PEDOT:PSS was in particular investigated. It was convincingly proven that the introduction of POSS unit and strong polar DMSO improved surface roughness, hydrophobicity, stability, friction resistance and electrical properties of PEDOT:PSS films. • The effect of the ratio of POSS compared to PEDOT:PSS was in particular investigated. • With assistance of POSS and DMSO, the hydrophobicity and abrasion resistance of PEDOT:PSS composite films were improved. • Optimized PEDOT:PSS/POSS (1:1) films show bending flexibility and great long-term stability when exposure to water. [ABSTRACT FROM AUTHOR]

Rational design of fiber-shaped gas sensors with both excellent mechanical properties and sensing performance is of great significance for boosting future portable and wearable sensing electronics, however, it is still a challenge. Herein, we develop a novel fiber-shaped hydrogen (H 2) sensor by directly electrochemically growing palladium (Pd) sensing layer on conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fiber electrode. This approach produces free-standing functional fiber (PEDOT:PSS@Pd) with promising mechanical features of flexibility, light weight, knittability and high mechanical strength, and good H 2 sensing performance at room temperature. The PEDOT:PSS@Pd fiber sensor exhibits short response time of 34 (± 6) s@1% and 19 (± 4) s@4% H 2 and excellent cycling stability. In addition, the fiber sensor remains good sensing behavior under different mechanical bending states, showing potential for constructing wearable sensor devices for timely H 2 leak detection. Therefore, this work has provided a smart design strategy of fiber-based gas sensor, offering an effective sensing platform and is believed to stimulate the development of wearable electronics. [Display omitted] • A novel flexible fiber-shaped H 2 sensor (PEDOT:PSS@Pd) was designed. • The fiber sensor possesses excellent mechanical properties and substrate-free. • The sensor displays short response time (19 ± 4 s@4% H 2) at room temperature. • The fiber sensor exhibits steady H 2 sensing behavior at different bending states. [ABSTRACT FROM AUTHOR]

Organic/inorganic hybrid fibers were prepared by gelation with facile post-treatment and used to assemble fiber TE generator for energy converting. • PEDOT:PSS/Te-NWs organic/inorganic hybrid fiber was prepared without use substrate. • These prepared fibers show higher TE performance than that of individual component. • The TE performance of these prepared fibers were greatly enhanced by post-treatment. • An flexible fiber TE generator was fabricated based on these prepared hybrid fibers. Fiber-based flexible thermoelectric (TE) generators are highly desirable for their capability of converting electricity from thermal energy and their potential applications in wearable and portable electron devices. Herein, by inducing the gelation of conducting polymer PEDOT:PSS, we successfully prepared PEDOT:PSS/tellurium nanowires (PEDOT:PSS/Te-NWs) organic/inorganic hybrid fibers for flexible TE generator without substrates. In this work, the higher TE performance of hybrid fibers were achieved compared to its individual components. Further, solvent post-treatment was employed as an effective strategy to enhance the TE performance and mechanical properties of the as-fabricated hybrid fibers. Therefore, a power factor as high as 17.8 μW m−1 K−2 with good mechanical stability was realized for H 2 SO 4 post-treated PEDOT:PSS/Te-NWs hybrid fiber with 50 wt% of Te-NWs. Additionally, a simple flexible TE generator with six pairs of p-n fiber legs with this post-treated hybrid fibers and carbon nanotube fibers (CNFs) was fabricated and showed the acceptable power density. This work may share lights on the development of organic/inorganic hybrid fiber-based flexible energy generators. [ABSTRACT FROM AUTHOR]

• PEDOT: PSS/rGO fibers are prepared by easily-accessible hydrothermal confinement reaction. • PEDOT:PSS/rGO fiber with simultaneously enhanced capacitance and mechanical properties can be obtained. • The fiber-shaped supercapacitor shows a high specific energy density of 10.68 Wh•kg−1 at the power density of 81.25 W kg−1. Implantable, flexible and easily reconfigurable supercapacitors with high power and energy densities are considered necessary for the development of portable and wearable electronics. However, obtaining a fiber-incorporating high electrochemical performance and fracture elongation remains a huge challenge. Here, we prepare a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)/reduced graphene oxide (PEDOT:PSS/rGO) fiber (PGF) with high-quality electrodes for supercapacitors by easily-accessible hydrothermal confinement reaction. The optimized P 3 G 7 F exhibits improved electrochemical performance including a high specific capacitance (C s) of 249.5 F g −1 at 0.5 A g −1 and good cycling stability. Moreover, after introducing the PEDOT:PSS, the elongation at break of the P 3 G 7 F is doubled to 13.9%. A symmetric supercapacitor (SSC) based on the P 3 G 7 F displays a high specific energy density of 10.68 Wh kg−1 at a specific power density of 81.25 W kg−1. The improved performance of the fabricated composite fiber is attributed to the unique structures of the rGO and PEDOT:PSS and their synergistic effect. This study introduces an opportunity for the development of next-generation flexible and wearable devices. PEDOT:PSS/rGO fibers are prepared via easily-accessible hydrothermal confinement method and the PEDOT:PSS/rGO fibers exhibit good capacitance and mechanical properties. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Homogeneous PEDOT:PSS:PANI water-dispersible was obtained via in situ composite. • Flexible PEDOT:PSS:PANI film was fabricated by a facile method. • TE performance of PEDOT:PSS:PANI film was enhanced by DMSO&CSA post-treatment. Organic thermoelectric (TE) materials are widely applied in various flexible portable products owing to their flexibility, transparency, and light weight. However, the performance of organic TE materials still needs to be further enhanced, seeking the composite preparation approach is one of the main strategies. Herein, an organic hybrid TE film, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and polyaniline (PANI), is prepared by solution in situ composite. In situ composite can not only enhance the TE property of the PANI, but also can increase the contact surface between PANI with the PEDOT:PSS, ameliorating the energy scattering effect. In addition, due to the introduction of PEDOT:PSS, the flexibility and solubility of PANI are effectively improved. When the feeding ratio of the aniline is 20 wt%, the electrical conductivity of the hybrid reached 43.7 S cm−1, which can be attributed to the strong interaction between PSS and PANI. After treated with DMSO&CSA, the hybrid reveals an apparent promotion of power factor as 4.26 μW m−1 K−2. The in situ composite method can provide a reference for the combination of various amino derivatives with conducting polymers, as well as to optimize the TE properties of hybrid films. [ABSTRACT FROM AUTHOR]

• Different effects of conductivity-enhancement reagents on self-healing of PEDOTs:PSS films were found. • EG treatment showed the greatest conductive healing, while H2SO4 post-treatment showed the best mechanical healing. • PEG or DMSO treatment showed negative influence on the self-healing of PEDOTs:PSS films. Conducting polymers (CPs), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films, have shown excellent applications in the field of flexible electronics. In most cases, conductivity-enhancement reagents, such as popular dimethyl sulfoxide (DMSO), ethylene glycol (EG) and polyethylene glycol (PEG) have been demonstrated as necessary additives. However, their effects on the self-healing performances of such films were still unknown. Here, effects of these reagents as well as inorganic concentrated sulfuric acid (H 2 SO 4) on the water-induced mechanical and electronic (conductive and thermoelectric) self-healing properties of PEDOT:PSS films were studied and corresponding mechanisms were illustrated. Meanwhile, analogous poly(3,4-ethylenedioxyselenophene):poly(styrene sulfonate) (PEDOS:PSS) film was investigated as a contrast. Treatment by EG showed 98 % recovery of conductivity and significantly reduced crack width after healing, while H 2 SO 4 post-treatment only improved the self-healing of mechanical properties but significantly weakened the electrical properties. PEG or DMSO treatment showed negative influence on the self-healing of PEDOTs:PSS films. Since flexible electronic applications of PEDOTs:PSS films are highly inseparable from various additives or post-treatment, this initial research will help to clarify and optimize the synergy between electronic and self-healing behaviors. [ABSTRACT FROM AUTHOR]