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Summary The development of functional porous materials has attracted the attention of many researchers because of the superior properties of these materials for various potential applications, such as catalysis, adsorption and separation, water splitting, renewable energy, nanomedicine, etc. In order to improve the performance of pristine porous materials, integrating porous materials with other species to make composite materials is often necessary. As a class of such porous materials, covalent-organic frameworks (COFs) show unique and interesting properties when combining with other materials to form functional composites. In this review, we highlighted recent research advances of composite materials based on the integration of COFs with metal or metal oxide nanoparticles, metal sulfides, silica, carbon materials, polymers, metal-organic frameworks, and other COFs. In particular, we focused on the synthetic methodology and associated applications of the resultant composite materials. Some of these composite materials exhibit improved performance as compared with individual components. Thus, this review aims to facilitate further development of COF-based composite materials for desirable applications.

Polyindole (PIn) has attracted extensive interest as promising energy storage materials owing to fairly good thermal stability, high redox activity and stability, however, it is challenging to prepare high-quality PIn in neutral solvents by electrochemical method. Herein, a simple route, based on MoS2 nanosheets as electrolytes, has been developed for the electrochemical preparation of PIn/MoS2 nanocomposite in acetonitrile solution. Due to the coordination interaction between indole and MoS2, the onset oxidation potential of indole in this medium was reduced to 0.5 V from 0.75 V determined in acetonitrile/LiClO4. The morphologies and structures of as-obtained PIn/MoS2 nanocomposite were characterized using SEM, TEM, XRD, Raman and XPS. The results of thermal analysis indicated that the PIn/MoS2 nanocomposite had an improved thermal stability relative to PIn and MoS2 nanosheets. Moreover, the specific capacitance of PIn/MoS2 nanocomposite was 8.3 times higher than that of PIn prepared acetonitrile/LiClO4. To the best of our knowledge, this is the first report on the high-efficiency electrodeposition of PIn/MoS2 nanocomposite in MoS2-based acetonitrile solution, which will be a promising candidate as a high efficient electrode material in the application of supercapacitors.

Photocatalysts derived from semiconductor heterojunctions that harvest solar energy and catalyze reactions still suffer from low solar-to-hydrogen conversion efficiency. Now, MXene (Ti3 C2 TX ) nanosheets (MNs) are used to support the in situ growth of ultrathin ZnIn2 S4 nanosheets (UZNs), producing sandwich-like hierarchical heterostructures (UZNs-MNs-UZNs) for efficient photocatalytic H2 evolution. Opportune lateral epitaxy of UZNs on the surface of MNs improves specific surface area, pore diameter, and hydrophilicity of the resulting materials, all of which could be beneficial to the photocatalytic activity. Owing to the Schottky junction and ultrathin 2D structures of UZNs and MNs, the heterostructures could effectively suppress photoexcited electron-hole recombination and boost photoexcited charge transfer and separation. The heterostructure photocatalyst exhibits improved photocatalytic H2 evolution performance (6.6 times higher than pristine ZnIn2 S4 ) and excellent stability.

A ternary single-walled carbon nanotubes/RuO2/polyindole (SWCNT/RuO2/PIn) nanocomposite was fabricated by the oxidation polymerization of indole on the prefabricated SWCNT/RuO2 binary nanocomposites. The nanocomposite was measured by FTIR, XRD, SEM, TEM, EDS and XPS, together with the electrochemical technique. The electrochemical results demonstrated that the symmetric supercapacitor used SWCNT/RuO2/PIn as electrodes presented 95% retention rate after 10000 cycles, superior capacitive performance of 1203 F·g−1 at 1 A·g−1, and high energy density of 33 W·h·kg−1 at 5000 W·kg−1. The high capacitance performance of SWCNT/RuO2/PIn nanocomposite was mainly ascribed to the beneficial cooperation effect among components. This indicated that the SWCNT/RuO2/PIn nanocomposite would be a good candidate for high-performance supercapacitors.

Homogenized PEDOT/CNT composite is difficult to be fabricated directly from aqueous solution without any solubilizers due to the limitation of insoluble EDOT. Through the introduction of hydroxymethyl group (MeOH) on the EDOT side chain, the designed EDOT-MeOH has very good solubility in aqueous solution. Herein, we firstly used one-step electrochemical co-deposition method to prepare a homogenized PEDOT-MeOH/SWCNT nano-network from the mixed aqueous solution of EDOT-MeOH and SWCNT. SEM and TEM indicated that PEDOT-MeOH uniformly coated on the surface of SWCNT and formed a three-dimensional interpenetrating network. With the increase in the deposited cycles, the thickness of PEDOT-MeOH coating on SWCNT increased regularly. The optimized PEDOT-MeOH/SWCNT nano-network in H2SO4 solution had a specific capacitance of 114.3 mF cm−2 at 5 mV s−1, which was higher than that of PEDOT-MeOH (58.8 mF cm−2), and showed good cycle stability of 80% after 5000 cycles. The enhanced performance mainly comes from the three-dimensional interpenetrating nano-network and the synergistic effect between SWCNT and PEDOT-MeOH. This work realized the facile combination of PEDOT derivatives and SWCNT from pure water solution, which will have good application in electrochemical energy storage devices and in the biosensors and bioelectronics areas due to its good biocompatibility.

GO–Ag2CrO4 composites were facilely synthesized by precipitation method in this study. GO–Ag2CrO4 composites were used to modify glassy carbon electrode and exhibited enhanced electrochemical response toward 4-NP. The optimal GO weight percentage was determined as 10% (The related modified electrode denoted as 10% GO–Ag2CrO4/GCE). Based on 10%GO–Ag2CrO4/GCE, a highly sensitive and selective voltammetric method was developed to detect 4-NP. The electrode can response to 4-NP with a good linear relationship in a wide range of 1.43 to 396.83 µmol/L. The determination limit (S/N = 3) is 0.095 µM, which is significantly lower than the permitted limits of 4-NP in water. The anti-interference ability, reproducibility and stability of 10%GO–Ag2CrO4/GCE were evaluated in details. Furthremore, the practical application of 10%GO–Ag2CrO4/GCE was tested by detecting 4-NP in actual water bodies. 10%GO–Ag2CrO4/GCE exhibits low detecting limit, high anti-interference ability, good reproducibility and stability, and high performance in actual water detection, which indicates it is a highly potential sensing platform for trace 4-NP detection.

Polyindole (PIn), combining the good properties of polypyrrole and poly(para-phenylene), has been gained significant attention. But the capacitive performances of PIn and its derivatives electropsynthesized in boron trifluoride diethyl etherate (BFEE) were unknown so far. So we first prepared the free-standing PIn film in BFEE and studied its capacitive property. The specific capacitance value of PIn could achieve 270.2 F g−1 at high current density of 10 A g−1. And the capacitance retained of PIn 84.06% after 3000 cycles. For further studying the effect of introducing alkyl chains on the electrochemical properties of PIn, poly1,3-di(1H-indol-1-yl)propane (P(IP-3)), poly1,6-di(1H-indol-1-yl)hexane (P(IH-6)), and poly1,12-di(1H-indol-1-yl)dodecane (P(ID-12)) bridged by alkyl chains with different lengths were electrosynthesized in BFEE. Through a series of experiments, we found that the specific capacitance performances of P(IP-3), P(IH-6), and P(ID-12) were poorer than PIn, indicating the introduction of alkyl chains altered the electrochemical properties of the π-conjugated backbone of PIn and lowered its the properties, which could be proved by scanning electron microscope.

Advanced wearable organic electronics have been widely studied for flexible textile-based strain sensors. However, two main issues to be addressed in wearable electronic sensors are the poor electron transfer under tensile conditions and water durability. In this work, we proposed an efficient strategy for the fabrication of a highly conductive commercial textile coated with poly(3,4-ethylenedioxythiophene) (PEDOT) via vapor phase polymerization (VPP) as a wearable thermoelectric (TE) strain sensor. The PEDOT-coated textile exhibited excellent mechanical elasticity and electrical properties in response to external strain. More importantly, the strain sensor showed a good strain after cyclic loading of an external stress. Moreover, the as-fabricated PEDOT-coated textiles show superior water durabilities due to the robust PEDOT coatings on the textiles through the in situ polymerization process. A large output voltage of 5.0 mV was achieved at a temperature gradient (ΔT) of 25 K, which is promising for textile generator applications. An optimized gauge factor (GF) of the strain sensor reached 54 at a strain of 1.5%, which has the capability to fully satisfy the demands of wearable electronic sensor devices.

For over two decades, metal–organic frameworks (MOFs) have drawn huge attention in the scientific community, with the promise to solve a wide variety of real-world problems. Despite overwhelming interests for this unique class of porous materials, the progress towards actual utilization falls short of the expectation due to the challenging transition from academia to industry. In this review, an up-to-date summary of the progress for MOF industrialization is presented. The latest developments in scalable production of MOFs and MOF processing from their powdered form are discussed to give a broad overview of the route to MOF commercialization. Their industrial utilization potentials are evaluated as well to provide useful insights for the future development in this field. This review aims to serve as an introduction for multidisciplinary research teams who are interested in developing a commercial market for MOF products. National Research Foundation (NRF) W. L. Teo thanks the Nanyang President’s Graduate Scholarship (NPGS) for funding his doctorate study. This research is supported by the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03).

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers with tailor-made structures and functionalities. To facilitate their utilization for advanced applications, it is crucial to develop a systematic approach to control the properties of COFs, including the crystallinity, stability, and functionalities. However, such an integrated design is challenging to achieve. Herein, we report supramolecular strategy-based linkage engineering to fabricate a versatile 2D hydrazone-linked COF platform for the coordination of different transition metal ions. Intra- and intermolecular hydrogen bonding as well as electrostatic interactions in the antiparallel stacking mode were first utilized to obtain two isoreticular COFs, namely COF–DB and COF–DT. On account of suitable nitrogen sites in COF–DB, the further metalation of COF–DB was accomplished upon the complexation with seven divalent transition metal ions M(II) (M = Mn, Co, Ni, Cu, Zn, Pd, and Cd) under mild conditions. The resultant M/COF–DB exhibited extended π-conjugation, improved crystallinity, enhanced stability, and additional functionalities as compared to the parent COF–DB. Furthermore, the dynamic nature of the coordination bonding in M/COF–DB allows for the easy replacement of metal ions through a postsynthetic exchange. In particular, the coordination mode in Pd/COF–DB endows it with excellent catalytic activity and cyclic stability as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction, outperforming its amorphous counterparts and Pd/COF–DT. This strategy provides an opportunity for the construction of 2D COFs with designable functions and opens an avenue to create COFs as multifunctional systems. National Research Foundation (NRF) This research is supported by the Singapore National Research Foundation Investigatorship (No. NRF-NRFI2018-03). K.P.L., S.Y.Q., and J.Q. acknowledge support from the Singapore National Research Foundation (NRF), Prime Minister’s Office, under its Medium-Sized Centre Program and Grant NRF-CRP16-2015-02. Computations were supported by the National Supercomputing Centre in Singapore, as well as the Centre for Advanced 2D Materials, funded under the NRF Medium-Sized Centre Programs. We thank Dr. Tian-Guang Zhan for helpful discussions.

Covalent organic frameworks (COFs) are excellent platforms with tailored functionalities in photocatalysis. There are still challenges in increasing the photochemical performance of COFs. Therefore, we designed and prepared a series of COFs for photocatalytic hydrogen generation. Varying different ratios of β-ketoenamine to imine moieties in the linkages could differ the ordered structure, visible light harvesting, and bandgap. Overall, β-ketoenamine-linked COFs exhibited much better photocatalytic activity than those COFs having both β-ketoenamine and imine moieties on account of a nonquenched excited state and more favorable HOMO level in the photoinduced oxidation reaction from the former. Specifically, after

Intracellular antioxidants such as glutathione (GSH) play a critical role in protecting malignant tumor cells from apoptosis induced by reactive oxygen species (ROS) and in mechanisms of multidrug and radiation resistance. Herein, we rationally design two multicomponent self-assembled photodynamic therapy (PDT) nanoagents, that is, Glup-MFi-c and Glud-MFo-c, which consist of respective GSH-passivation and GSH-depletion linkers in metal−organic frameworks encapsulated with photosensitizers for a deeply comprehensive understanding of GSH-based tumor PDT. Multicomponent coordination, π−π stacking, and electrostatic interactions among metal ions, photosensitizers, and bridging linkers under the protection of a biocompatible polymer generate homogeneous nanoparticles with satisfied size, good colloid stability, and ultrahigh loading capacity. Compared to the GSH-passivated Glup-MFi-c, the GSH-depleted Glud-MFo-c shows pH-responsive release of photosensitizer and [FeIII(CN)6] linker in tumor cells to efficiently deplete intracellular GSH, thus amplifying the cell-killing efficiency of ROS and suppressing the tumor growth in vivo. This study demonstrates that Glud-MFo-c acts as a ROS amplifier, providing a useful strategy to deeply understand the role of GSH in combating cancer. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version This research is supported by the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03), the Singapore Academic Research Fund (RT12/19), the National Natural Science Foundation of China (31471268), and the National Key Research and Development Program of China (Stem Cell and Translational Research, 2016YFA0101202).

Developing high-rate anode materials with large capacity for lithium ion batteries (LIBs) is quite necessary for the booming electric vehicles industry. The utilization of stable and conductive hollow structures for electrode composite materials could make the desired performances possible in the future. Thus, in this study, a hollow structured Ni–CoSe2 embedded in N-doped amorphous carbon nanocomposite (Ni–CoSe2@NC) has been successfully synthesized with metal–organic frameworks (MOFs) as precursors. Such strategy integrates both the merits of the multicomponents and the hollow structure; the latter could facilitate both mass and charge transport, and the former (the N-doped carbon) could not only offer plenty of surface defects, improving the surface capacitive contributions, but also stabilize the electrode structure during the charge/discharge processes. As a result, the metal selenide composite delivers outstanding high-rate properties with good stability as the anode for LIBs. The structure and comp...

The development of artificial enzyme mimics has been rapidly growing in recent years, and it is attracting increasing attention owing to their remarkable advantages over natural enzymes. Herein, we developed a general and facile method to fabricate efficient glutathione peroxidase (GPx) mimics by grafting selenium-containing molecules (phenylselenylbromide, PhSeBr) to a Zr(IV)-based UiO-66-NH2 framework. In the presence of glutathione (GSH) serving as substrate, the fabricated UiO-66-Se catalysts can catalyze the reduction of hydroperoxides. The as-prepared UiO-66-Se systems show good catalytic activity over three cycles. These high-efficiency GPx mimic metal-organic frameworks (MOFs) are endowed with excellent thermal and structural stability, providing a promising avenue for the development of artificial enzyme mimics.

A micron-thick flexible layered RuO2·1.18H2O/PEDOT-PSS film with high electric conductivity of about 306 S cm−1 (sheet resistance of film of 7.1 Ω sq−1) was prepared using commercial PEDOT-PSS dispersion and RuO2·1.18H2O nanoparticles through a simple, low-cost vacuum filtration technology. The layered flexible film could be used as a rope to hang up 300 gram weight and as a conducting wire in a circuit to light a blue LED lamp. The symmetrical supercapacitor based on the layered flexible films showed high specific capacitance of 591 F g−1 (volumetric specific capacitance of 530 F cm−3) at 10 mV s−1, excellent long-term cycling stability (capacitance retention of 91.5%) after 5000 cycles, and high energy density of 18 Wh kg−1 at high power density of 5000 W kg−1. The flexible film as function as current collector and active material simultaneously will have practical application in miniaturized flexible supercapacitors.

Layered WS2 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 WS2 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 WS2/PEDOT:PSS film as miniature supercapacitors electrode materials was easily prepared by vacuum filtration method. The WS2/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 WS2/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 WS2/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 H2SO4 solution. Besides, the capacitance retention could reach 107% of initial specific capacitance after 5000 charge-discharge cycles. Moreover, the flexible device based on WS2/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 WS2/PEDOT:PSS film has a potential application in flexible and miniature supercapacitors without any other substrates as current collectors.

Nanowire poly (3,4-dihydro-2H-thieno [3,4-b] [1,4]dioxepin-3-yl)methanol (PProDTM) free-supporting films with conductivities around 1.92 S cm−1 were prepared using a template-free electropolymerization method. The structure, morphology, mechanical properties, and thermal stability of the PProDTM films were characterized by Fourier transform infrared spectroscopy, UV–vis spectroscopy, scanning electron microscopy, dynamic mechanical analysis and thermogravimetric analysis. Moreover, the capacitance performances of PProDTM films were investigated in aqueous and organic electrolytes (acetonitrile (ACN) and dichloromethane (DCM)). In 0.1 M H2SO4, a symmetrical supercapacitor based on PProDTM exhibited specific capacitance of 89.2 F g−1 at a current density of 1.0 A g−1, an energy density of 3.1 Wh kg−1 at power density of 0.5 kW kg−1 and the cycling capacitance retention was 74.8% after 5000 cycles. As the scan rate and current density increased, the specific capacitance of PProDTM films clearly decreased in DCM, but no obvious changes occurred in water and ACN. In ACN containing 0.1 M Bu4NBF4, a symmetrical supercapacitor based on PProDTM exhibited specific capacitance of 99.6 F g−1 at a current density of 1.0 A g−1, an energy density of 3.5 Wh kg−1 at power density of 0.5 kW kg−1 and the cycling capacitance retention was 82.2% after 5000 cycles. These results imply that our flexible free-supporting PProDTM films are promising for future use in supercapacitors.

Three-dimensional carbon materials containing oxygen/nitrogen functional groups are facilely prepared by the carbonization of conjugated polyindole hollow nanospheres with the activation of 15 M KOH at 900 °C. The pore structures, surface elemental composition, and hydrophilicity of samples are studied by nitrogen adsorption–desorption isotherms, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, Raman, and contact angle, respectively. The specific surface area of as-prepared carbon material with the micro/mesopore size distribution of 0.5–4 nm and macropores more than 100 nm is 2238 m2 g–1. The capacitance characterizations demonstrate that the specific capacitance of as-prepared carbon can reach 328 F g–1. The device built from such carbon materials exhibits high energy density of about 15 Wh/kg, and 91% retention of original capacity after 10000 cycles. These positive data suggest that as-prepared th...

The organic/inorganic composites are considered as a promising strategy to gain high thermoelectric (TE) performance. Although many efforts have been focused on composites, complicated methods are real hindrance to the development of TE materials. Here, we demonstrate a potential TE thin film comprising highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and chemically exfoliated MoS2 (ce-MoS2) nanosheets by layer-by-layer (LbL) assembly method. This work achieves the effective integration of composite, treatment, and electron transfer based on the advantages of PEDOT:PSS and ce-MoS2. On the one hand, the negative charged ce-MoS2 nanosheets facilitate the formation of heterostructure TE films with positive charged PEDOT and reduce the oxidation level of PEDOT, which would favor an enhanced thermopower (21.9 μV K–1). On the other hand, the simultaneous enhancement in the electrical conductivity (867 S cm–1) of PEDOT:PSS/ce-MoS2 composite film is caused by dimethyl sulfoxid...

Freestanding flexible capacitive materials are ideal for use in bendable electronic devices. However, it is difficult to prepare pure PEDOT films in a freestanding state by chemical and electrochemical methods. Here, we used a simple strategy of introducing alkoxy, ether, ester, and amide chains for bridging two EDOT units to form precursors, which could then be electrodeposited readily to produce freestanding and flexible films. The precursor with the amide group was suitable for obtaining higher-quality films with improved thermal stability, mechanical properties, and capacitive performance. In addition, the asymmetric PBEDTA//PEDOT capacitors exhibited a capacitance retention rate of 98.5% after 5000 cycles, which is higher than those of PBEDTH//PEDOT (92.7%), PBEDTG//PEDOT (80.5%), and PBEDTE//PEDOT (86.8%) capacitors. This result indicates that the polymer films and, in particular, the PBEDTA films, are suitable for use in flexible supercapacitors.

Currently, the nanocomposites based on MoS2 and conducting polymer (CPs) are mainly prepared by the chemical oxidation polymerization of monomers with the presence of MoS2 nanosheets. The disadvantage is that the aggregation and re-stacking of monolayered MoS2 occur easily. In the electrosynthesis of CPs, monolayered MoS2 with negative charges can be uniformly doped into CPs film, thus avoiding the above disadvantage. Herein, a direct electrochemical deposition method is used to incorporate the exfoliated monolayered MoS2 into BF4−-doped poly(3,4-ethylenedioxythiophene) (PEDOT(BF4−)) film, forming PEDOT(BF4−)/MoS2 nanocomposite. The as-prepared monolayered MoS2, PEDOT(BF4−) and PEDOT(BF4−)/MoS2 nanocomposite are characterized by AFM, SEM, TEM, EDX and electrochemical means. The results indicate that PEDOT(BF4−)/MoS2 nanocomposite has specific capacitance of 149.8 mF cm− 2 at 1.0 mA cm− 2, which is 4.3 times higher than PEDOT(BF4−) (35 mF cm− 2). And the specific capacitance of PEDOT(BF4−)/MoS2 nanocomposite remains about 85% of the initial capacitance after 1000 cycles at 8 mA cm− 2. Therefore, the monolayered MoS2 doped into PEDOT(BF4−) film can further improve the capacitance performance of PEDOT(BF4−), which is attributed to the porous nano-network structure of composite and the synergistic effect between MoS2 and PEDOT in the composite.

Porous bimetallic PdNi catalysts were fabricated by a novel method, namely, reduction of Pd and Ni oxides prepared via calcining the complex chelate of PdNi-dimethylglyoxime (PdNi-dmg). The morphology and composition of the as-prepared PdNi were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Furthermore, the electrochemical properties of PdNi catalysts towards ethanol electrooxidation were also studied by electrochemical impedance spectrometry (EIS), cyclic voltammetry (CV) and chronoamperometry (CA) measurement. In comparison with porous Pd and commercial Pd/C catalysts, porous structural PdNi catalysts showed higher electrocatalytic activity and durability for ethanol electrooxidation, which may be ascribed to Pd and Ni property, large electroactive surface area and high electron transfer property. The Ni exist in the catalyst in the form of the nickel hydroxides (Ni(OH)2 and NiOOH) which have a high electron and proton conductivity enhances the catalytic activity of the catalysts. All results highlight the great potential application of the calcination-reduction method for synthesizing high active porous PdNi catalysts in direct ethanol fuel cells.

Metal-organic framework (MOF)-based derivatives have attracted an increasing interest in various research fields. However, most of the reported papers mainly focus on pristine MOF-based derivatives, and research studies on functional MOF-based derivative composites are rare. Here, a simple strategy has been reported to design functional MOF-based derivative composites by the encapsulation of metal nanoparticle (MNP) in MOF matrixes (MNP@MOF) and the high-temperature calcination of MNP@MOF composites. The as-prepared MNP@metal oxide composites with a hierarchical pore structure exhibited excellent catalytic activity and high stability for the CO oxidation reaction.

One of the most important non-destructive methods for on-site analysis of bronze artifacts is portable X-ray fluorescence (XRF). However, bronze artifacts are usually heterogeneous in composition due to, among other things, the segregation of lead, which is hard to be eliminated through annealing treatments. In the present work, Cu-Sn-Pb alloys with homogenous composition and microstructure is fabricated by powder metallurgy technique. The suitability of the standard curve using Cu-Sn-Pb alloys by powder metallurgy as the standard samples for XRF on the analysis of bronze artifacts is evaluated. It is shown that this proposed method can be transferred to portable XRF to acquire accurate on-site composition information of bronze artifacts.

The regulation of oxidation levels is of great importance as an efficient way to optimize the thermoelectric (TE) performance of conducting polymers. Many efforts have been devoted to the acquisition of a high TE performance for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) by oxidation/reduction post treatment to achieve an effective compromise. However, a strong oxidant/reductant is usually employed to tune the TE performance of PEDOT:PSS with high electrical conductivity (σ) and Seebeck coefficient ( S), and it also presents a number of operational challenges depending on a fast reaction rate. Herein, nontoxic polyethylenimine ethoxylated (PEIE) served as a reductant to successfully realize an enhanced S for PEDOT:PSS, besides playing a significant anion-blocking role in enabling the efficient modulation of the oxidation level by sulfuric acid (H

Background Pain is a subjective experience derived from complex interactions among biological, environmental, and psychosocial pathways. Sex differences in pain sensitivity and chronic pain prevalence are well established. However, the molecular basis underlying these sex dimorphisms are poorly understood particularly with regard to the role of the peripheral nervous system. Here we sought to identify shared and distinct gene networks functioning in the peripheral nervous systems that may contribute to sex differences of pain in rats after nerve injury. Results We performed RNA-seq on dorsal root ganglia following chronic constriction injury of the sciatic nerve in male and female rats. Analysis from paired naive and injured tissues showed that 1513 genes were differentially expressed between sexes. Genes which facilitated synaptic transmission in naïve and injured females did not show increased expression in males. Conclusions Appreciating sex-related gene expression differences and similarities in neuropathic pain models may help to improve the translational relevance to clinical populations and efficacy of clinical trials of this major health issue. Electronic supplementary material The online version of this article (10.1186/s12864-019-5512-9) contains supplementary material, which is available to authorized users.

The morphology of electrode material is generally critical to affecting their electrochemical performance. Here, a porous poplar flower-like PEDOT-MeOH/PEG/WS2 hybrid material is successfully prepared using a simply co-electrodeposition method. With the assistance of poly(ethylene glycol) (PEG), the chemically exfoliated WS2 nanosheets are doped into poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-MeOH) film. The formation of a porous poplar flower-like PEDOT-MeOH/PEG/WS2 composite is proved by scanning electron microscopy, transmission electron microscopy, infrared spectra, energy-dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. The maximum capacitance of the composite reaches 461.5 mF cm−2, which is 1.6 times greater than that of PEDOT-MeOH/PEG film. As-fabricated PEDOT-MeOH/PEG/WS2 composite can keep 85.8% of the initial areal capacitance after 5000 cycles. Additionally, PEDOT-MeOH/PEG/WS2-based symmetrical supercapacitor presents a capacitive capacity of 62.7 mF cm−2 at 0.5 mA cm−2, specific energy of 8.72 × 103 μWh cm−2 at 2.62 × 105 μW cm−2, and capacitive retention of 83.3% after 5000 cycles with a 100% coulombic efficiency. The capacitance improvement of PEDOT-MeOH/PEG/WS2 composite is closely related to porous poplar flower-like structure as well as the cooperation-enhancing effect between PEDOT-MeOH and WS2. These results imply that PEDOT-MeOH/PEG/WS2 composite will have great potential application in the field of the energy storage.

Hierarchical structural PEDOT@MoS2 nanocomposite is synthesized via a facile electrochemical co-deposition of the intercalation of PEDOT into flower-like MoS2 microspheres. The SEM, TEM, and other characterization results demonstrate the hierarchical PEDOT@MoS2 composite with an enlarged interlayer spacing of MoS2 to 1.02 nm, in which PEDOT nanoparticles act as intercalation, and flower-like MoS2 microspheres are used as a substrate for growth. The electrochemical characterizations indicate that the PEDOT@MoS2 electrode has an ultra-high specific capacitance of 4418 mF cm−2 at 2 mA cm−2 and remarkable cycling stability, retaining 100% of the initial capacitance at a high current density of 100 mA cm−2 after 10,000 cycles. The symmetric PEDOT@MoS2 supercapacitor presents a high energy density of 88.3 mWh cm−2 at 60 mW cm−2, and outstanding cycling stability (93% after 10,000 cycles). These prominent electrochemical performances are attributed to the expanded interlayer spacing, the synergistic effect between PEDOT and MoS2, the low resistance, along with the PEDOT@MoS2 porous structure, indicating great potential applications of the PEDOT@MoS2 electrode in the energy storage field.

An active material electrode with high areal specific capacitance is needed for a high-performance supercapacitor, but it is difficult to achieve this goal for PEDOT-based composites. Here, a novel hierarchical core/shell PEDOT@MoS2 composite was assembled by the electrochemical co-deposition of EDOT and MoS2 submicron spheres. The SEM, TEM images of the as-obtained composite explicitly reveal the core/shell heterostructure of PEDOT@MoS2 with a diameter of about 800 nm. The electrochemical characterizations show that the optimized PEDOT@MoS2 composite possesses a high specific capacitance of 2540 mF cm−2 at 1 mA cm−2 and excellent capacitance retention of 98.5% after 5000 cycles at a high current density of 100 mA cm−2. The assembled P@M-4//PEDOT asymmetric supercapacitor shows a high energy density of 937 Wh m−2 at 6500 W m−2, and outstanding cycling stability with capacitance retention of 100% after 5000 cycles. It is proposed that the enhanced performances are attributed to the robust hierarchical core/shell structures and the synergic effect between PEDOT and MoS2, which is expected to become a promising candidate for applications in high-performance supercapacitors.

Poly(3-thiophene boronic acid) (PTBA) as a boronic acid functionalized conducting polymer has been developed in sensors and electrochromics due to the characteristic feature of boronic acid groups, however, the previously reported PTBA had a very low electrical conductivity of 2.0 × 10−9 S cm−1, and up to day there are no researches on PTBA used as thermoelectric materials. In this study, a free-standing PTBA film with high-quality was firstly electrosynthesized in acetonitrile containing boron trifluoride diethyl etherate (1:1 by volume). SEM, FT-IR, UV–vis and TG were conducted to investigate morphologies, structures and thermal stability of PTBA films. Notably, the introduction of boronic acid groups in polythiophene significantly increases the Seebeck coefficient from 72.5 to 125.0 μV K−1, electrical conductivity from 0.014 to 0.027 S cm−1, and power factor from 0.0074 to 0.0422 μW m−1 K−2. Free-standing PTBA film will be a promising material in the field of thermoelectric.

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.

Relative to those polymers based on thiophene, the polymers derived from planar symmetrical thieno[3,2- b ]thiophene moieties exhibit highly ordered crystalline, fast charge transport behaviors and good stability. Herein, the effects of the polymerization solvent, potential, and temperature on the structure, morphology, thermal stability and capacitive performance of the electrodeposited poly(thieno[3,2 -b ]thiophene) (PTT) film were studied by FT-IR, SEM, TG and electrochemical methods, respectively. It was found that the PTT film had a very high specific capacitance (627.5 F g −1 at 15 A g −1 ) in acetonitrile/0.1 M LiClO 4 , even at high current density of 100 A g −1 , its specific capacitance still reached 531 F g −1 . Additionally, the morphology and capacitance performance of PTT film were greatly affected by the polymerization solvent, potential, and temperature parameters. Therefore, it is believed that PTT can be a meaningful capacitive material if only the preparation condition is well optimized.

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/H2O 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 H2SO4 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.

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.

Large-scale chloromethyl functionalized poly(3,4-ethylenedioxythiophene) nanowires (PEDOT-MeCl), poly(2-chloromethyl-2,3-dihydrothieno[3,4-b][1,4]dioxine), were easily electrodeposited in acetonitrile solution containing 0.1 M lithium perchlorate without any templates. The PEDOT-MeCl nanowires were characterized by FT-IR, TG, SEM, TEM and electrochemical technologies. The nanowires structural PEDOT-MeCl with diameter of about 20 nm displayed good thermal stability and high specific capacitance of 174 F g−1 at 25 mV s−1. Furthermore, the energy density of the symmetric supercapacitor built by PEDOT-MeCl nanowires reached 6.95 Wh kg−1 at a power density of 1625 W kg−1, and the specific capacitance retention was 81% after 1000 cycles. The above information implied the bright prospect of the PEDOT-MeCl nanowires as electrode material for supercapacitors.

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 CH3CN solution was about 126 mF cm−2 at 1.5 mA cm−2 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−2 at 1.5 mA cm−2 and to make the cyclic stability increase to 81.8 % capacitance retention after 5000 cycles when the equivalent BFEE was added into the CH3CN solution containing 0.05 M Bu4NBF4 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.

Light, as an important environmental signal, generally brings about a broad regulation in fungal metabolism. In this work, we aim to explore the light-responded metabolic rules so as to further develop a feasible and effective light regulation strategy for production of anticancer polyketide 1403C by marine fungus Halorosellinia sp.. Light derived production enhancement of polyketides was first found in shake flask. To further understand this well working black box, light-responded cell growth, polyketides biosynthesis, metabolic behaviors (enzymes activities and organic acids levels) and mycelia morphology were then investigated in 5-L bioreactor. By comparing cultures under constant irradiation and dark conditions, the entire bioprocess was divided into two phases. During 0-60h, light presumably stimulated relevant metabolism to generate sufficient energy, NADPH and carbon skeleton, particularly malonyl-CoA, which was favorable for mycelia growth and polyketides accumulation. After 60h, light did harm to biomass and polyketides production. Consequently, a light-dark shift strategy was proposed and verified in 5-L bioreactor. It led to a maximal 1403C production of 1.67g/L, which was 24% and 74% higher than those obtained under constant irradiation and dark conditions, respectively.

In this work, poly(N-methyl-3,4-dihydrothieno[3,4-b][1,4]oxazine) (PMDTO), a new nitrogen poly(3,4-ethylendioxythiophene) (PEDOT) analogue, was synthesized by an electrochemical deposition method, and the capacitive properties of PMDTO were investigated and compared with those of PEDOT. The structure and morphology of PMDTO were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The pseudocapacitive properties of the as-prepared PMDTO electrodes have been examined by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) measurements and electrochemical impedance spectroscopy (EIS) in 0.1 mol L−1 CH3CN–Bu4NBF4 electrolyte solution. The as-prepared PMDTO electrode showed a high specific capacitance of 154.3 F g−1 at a discharge current density of 3 A g−1 and exhibited cycling stability with the maximal capacitance retention of nearly 71% after 500 cycles at a high current density of 10 A g−1. Additionally, the asymmetrical supercapacitor based on PMDTO and PEDOT electrodes exhibited a maximum specific capacitance of 63.5 F g−1 and an energy density of 12.7 W h kg−1 at a power density of 0.59 kW kg−1. These results implied that the PMDTO electrode can be used as a potential electrode material for supercapacitors.

For organic thermoelectric materials, a main challenge is to achieve high electrical conductivity and a large Seebeck coefficient, in order to improve the power factor. Here we suggest a simple way to address this issue through the addition of a small amount of liquid-phase exfoliated MoS2 nanosheets into poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) solutions by direct vacuum filtration. The effects of exfoliated MoS2 nanosheets in common organic solvents on the thermoelectric properties of PEDOT:PSS were investigated. The organic solvent-assisted exfoliated MoS2 nanosheet solution was found to play an important role in improving the thermoelectric performance of the PEDOT:PSS thin film. Common organic solvents effectively removed some of the PSS during the formation of the film, resulting in a significantly enhanced electrical conductivity (1250 S cm−1) for the PEDOT:PSS/MoS2 (PM) thin film. On the other hand, the introduction of MoS2 nanosheets in PEDOT:PSS led to a slight increase of the Seebeck coefficient from 14.5 to 19.5 μV K−1 without a significant reduction of the electrical conductivity of the PM thin film. An optimized power factor of 45.6 μW m−1 K−2 was achieved for the PM thin film with 4 wt% MoS2 exfoliated in an N,N-dimethylformamide (DMF) solution. The exfoliated MoS2 nanosheets in DMF exhibited a better effect on the thermoelectric performance of the PM composites than did those in other organic solvents. The method used here suggests a novel strategy for improving both electrical conductivity and the Seebeck coefficient, and hence optimizing the thermoelectric performance of the PEDOT:PSS thin film.

In this work, a high-capacitance hybrid nanocomposite based on reduced graphene oxide (RGO) and polyindole (PIn) was fabricated via an in situ chemical oxidative polymerization approach. The structure and morphology of PIn/RGO were investigated by FT-IR, Raman spectroscopy, SEM and TEM. The electrochemical properties of this electrode in aqueous H2SO4 electrolyte were also investigated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). Compared to RGO and PIn electrodes, the PIn/RGO hybrid nanocomposite shows a large improved specific capacitance of 322.8 F g−1 at 1.0 A g−1, good stability with a cycling efficiency of 94.5% after 1000 cycles, and high energy density of 36 W h kg−1 at a high power density of 5000 W kg−1. The enhanced performance is proposed to arise from the synergetic effect between PIn and RGO. In addition, the symmetric PIn/RGO//PIn/RGO supercapacitor showed specific capacitance of 99.8 F g−1 and only 3.7% decay after 1000 cycles. These results imply that PIn/RGO should be a promising electrode material for supercapacitor applications.

Bimetallic nitrides are regarded as promising electrode material for hydrogen evolution reactions (HER) via electrochemical water splitting. We fabricated two types of bimetallic nitride nanopore arrays based on the anodized TiO2 nanotube array template (NiTiNx@TiN, CoTiNx@TiN). The NiTiNx@TiN composite nanotubes exhibit superior HER performance compared to single metal nitrides, the thin film counterpart, and cobalt titanium nitride nanopore arrays. The enhancement can be attributed to the large electrochemical reactive surfaces and the conductive TiN nanopores as both scaffold and current transporter. The first-principle calculation indicates that the coordination states of Ni–Ti atoms favor the adsorption of the intermediate during the hydrogen production process. Such nanopore arrays should be also useful in OER and supercapacitors.

Photocatalytic CO2 reduction suffers from the weakness of high energy barrier, low efficiency and poor selectivity. Exploring effective strategy to enhance the adsorption and activation behavior of CO2 molecules is an alternative approach to boost CO2 photoreduction performance. In this work, abundant oxygen vacancies (VO) are introduced onto Bi2Sn2O7 nanoparticles (NPs) by decreasing their size down to about 4 nm. The VO mediated NPs exhibit a tremendous 8.1 times enhanced performance than the bulk counterpart towards CO2-to−CO conversion in pure water. This is attributed to fast charge diffusion and abundant Vo for effective CO2 adsorption and activation in the ultra-small nanoparticles. The VO mediated Bi2Sn2O7 NPs have electron back donation nature and optimized electronic structure for effectively activating CO2, which were demonstrated by density functional theory calculations. During the reduction process, the Vo can effeciently stabilize the COOH* intermediates, and also lower the energy barrier of CO desorption determining step.

Tailoring interior structure of porous nanomaterials is of great important for efficient CO oxidation. Here, porous Co3O4 with complex interior structure (hollow structure and yolk-shell structure) derived from metal-organic frameworks are successfully developed via an efficient and controllable calcination method. Compared with yolk-shell Co3O4 catalysts, the hollow Co3O4 exhibited excellent catalytic performance with onset at temperature of 60 °C and completed CO conversion at 140 °C. The fabricated hollow Co3O4 catalysts could obtain completely conversion of CO under 140 °C for 20 h, suggesting remarkable cycling stability. The enhanced catalytic activity and cycling stability are ascribed to the special properties of porous Co3O4 catalysts. Our work offers a facile approach to facilitate the development of catalysts with controllable interiors and extend their practical applicability.

Nitroaromatic pollutants with unusually strong adsorption affinity are highly attractive candidates for creating 2D molecular assemblies on the surface of graphene, which is crucial to prepare high-quality N-doped graphene by post-treatment. Herein, the few-layered crumpled N-doped graphene (5-NIGN) with high N content is successfully prepared by mixing 5-nitroindole (5-NI), ammonia, and graphene oxide (GO) and using a simple hydrothermal method followed by the post-treatment process of vacuum freeze-drying and annealing. It is found that the rapid assembly of 5-NI effectively suppresses the aggregation of the products in the reduction process of GO, so that the thickness of as-prepared 5-NIGN is 4.21 nm, very close to that of GO (4.01 nm). Compared with the N-doped graphene (GN) derived from the system of GO containing ammonia (341 F g−1), 5-NIGN exhibits higher capacitance of 457.4 F g−1 at 1 A g−1 and prominent long-term life (115% of capacitance maintenance upon 10,000 cycles) within the voltage window of 1.0 V. Furthermore, the supercapacitor assembled by 5-NIGN electrodes can deliver the energy density of 15.5 Wh kg−1~18.5 Wh kg−1 at the power density of 8000 W kg−1~800 W kg−1. These results indicate that the 5-NIGN material will have potential advantages in the realm of electrochemical energy storage.

The introduction of fluorine into a compound or material is known to impart a range of interesting functionalities; however, the poor electrochemical capacity of existing fluorinated polymers limits their application in the field of energy storage. Thus, we herein report the successful preparation of several fluorinated polyindole materials exhibiting high energy storage behaviours using a simple electropolymerization strategy. Scanning and transmission electron microscopic images reveal that the monofluorinated polyindoles are mainly composed of one-dimensional (1D) nanofibers and nanorods, whereas 1D nanowires and two-dimensional (2D) nanosheets are obtained for the difluorinated polyindoles. Interestingly, the prepared fluorinated polyindoles are found to exhibit the highest specific capacitances among all reported fluorinated materials (i.e., 261–528 F g−1 at 18 A g−1). In addition, they exhibit a good cycle stability as well as a high rate capability. Our results indicate that fluorinated nano-polyindoles can be considered as promising electrode materials for energy storage applications.

Conducting polymer-based composite aerogel film is desired to be used as thermoelectric (TE) materials due to its good flexibility and ultralow thermal conductivity. Here, we proposed the simple freeze drying method to fabricate free-standing poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS)-based aerogel films without any crosslinker addition. The evolutions of morphology and TE performance were systemically investigated with various organic solvent addition. Furthermore, a series of the PEDOT:PSS/tellurium nanowires (Te-NWs) composite aerogel films was prepared, and the relationship between the structure and the charge-transport mechanism of the binary complex system was explored based on series and parallel models. Finally, an efficient dimethyl sulfoxide-vapor annealing was employed to further optimize the TE performance of PEDOT:PSS/Te-NWs composite aerogel films. The ZT value was estimated to be 2.0 × 10-2 at room temperature. On the basis of the flexibility and highly enhanced TE performance, a prototype TE generator consisting of p-type PEDOT:PSS/Te-NWs aerogel films and n-type carbon nanotube fibers as legs has been fabricated with an acceptable output power of 1.28 μW at a temperature gradient of 60 K, which could be potentially applied in wearable electronics.

We herein compare the thermoelectric performance of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and Bi2Te3 nanowires (Bi2Te3-NWs) composites (PEDOT:PSS/Bi2Te3-NWs) including layer-by-layer assembly and hybrid structures by drop-cast as well as pellets. The Bi2Te3 nanowires are synthesized by a wet-chemical method. The hybrid PEDOT:PSS/Bi2Te3-NWs film with 10 wt% Bi2Te3-NWs has a higher electrical conductivity (401 S cm−1) and power factor (10.6 μW m−1 K−2) than that of layer-by-by layer assembly film. The Seebeck coefficient keeps mostly unchangeable for hybrid films as the increasing Bi2Te3-NWs which is different from layered films. The PEDOT:PSS/Bi2Te3-NWs pellets have a larger Seebeck coefficient (54 μV K−1) with a lower electrical conductivity (12.4 S cm−1) leading a lower power factor. The hybrid method for preparation of PEDOT:PSS/Bi2Te3-NWs film is a more efficient way for the enhancement of thermoelectric performance.

Conductive thiophene-based polymers have garnered great attention for use in organic electron materials such as electrochromic and thermoelectric materials. However, they suffer from poor electron transport properties and long-term stability, leading to limited development eventually. Here, we proposed a strategy of functionalized thiophene-based polymers with oligo(ethylene glycol) or alkyl side chains and synthesized a series of poly(3,4-ethylenedioxy bithiophene)s (PEDTs) to tune their electrochromic and thermoelectric properties. An alkyl group bearing electronic ability at the thiophene ring effectively achieved a large increase in the electrical conductivity with nearly invariable Seebeck coefficient, resulting in an enhancement by 1 order of magnitude for the thermoelectric power factor. Moreover, the electrochromic properties of functionalized PEDTs gained an effective improvement in the optical contrast and coloration efficiency as well as stability with multicolor changes between neutral and oxidized states. The functionalized PEDTs can be proposed as an alternative strategy to tune the electrochromic and thermoelectric properties for organic polymer materials.

Here, a facile strategy is reported to efficiently hybridize metal nanoparticles (MNPs) with typical metal–organic frameworks (MOFs) of ZIF-8 (zeolitic imidazolate framework-8), which employs bovine serum albumin (BSA, a serum albumin protein derived from cows) as the amphiphilic stabilizer to increase the affinity of MNP toward MOFs. For instance, the as-synthesized PdNPs/ZIF-8 composites with diameter from 100 to 200 nm always maintain well-defined crystalline structure, and the PdNPs with small size of ∼2 nm are well-dispersed in the crystal of MOFs without serious aggregations due to the BSA stabilizer. In Suzuki cross-coupling reactions of aryl halide, the PdNPs/ZIF-8 as catalysts have exhibited high activity and satisfied reusability owing to the use of BSA stabilizer as well as the fixing of MOFs matrixes. In addition, the strategy also can be extended to synthesize other kinds of MNPs/MOFs hybrid composites with tunable particle size, which brings more opportunity for functional MOFs hybrid materials.

Fluoropolymers have great values in the scientific research and the industrial application, but poor electrochemical properties restricted their use as charge storage materials. In this work, we developed a high-performance poly(5-fluoroindole) (5-PFIn) as charge storage material by simple electrodeposition of 5-fluoroindole in acetonitrile solution containing 0.1 M Bu4NBF4. The morphologies, structures and electrochemical properties of as-prepared 5-PFIn were studied by SEM, FT-IR, UV–vis, BET and electrochemical techniques, respectively. The electrochemical results indicated that the 5-PFIn nanowires in 1.0 M H2SO4 electrolyte showed a full-covered strongly responsive redox behavior between −0.4 V and 0.85 V, which remarkably differed from polyindole (PIn) and poly(5-methoxyindole) (5-PMeOIn) and poly(indole-5-carboxylic acid) (5-PICA). As a result, 5-PFIn exhibited high specific capacitance of 416 F g−1 at 10 A g−1, good cycling stability of 83% after 5000 cycles and slow self-discharge behavior, which were superior to those of PIn (103 F g−1, 68%), 5-PMeOIn (114 F g−1, 70%) and 5-PICA (286 F g−1, 70%). These results indicated that the fluorine-substituted conjugated PIn will be one of the most promising fluoropolymers electrode materials for supercapacitor application.