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With the development of science and technology and electronic industry, electromagnetic wave pollution has become the fifth largest pollution in the world today, so it is very important to develop a material with good wave absorbing properties. In this study, polyaniline was loaded onto the surface of carbon nanotubes (CNTs) bundles in Buckypaper by electropolymerization, and epoxy resin was used as the matrix to prepare a polyaniline (PANI)/Buckypaper/EP composite absorber with integrated structure and function. The research shows that the CNTs are prepared into Buckypaper with a three‐dimensional porous structure by vacuum filtration. This three‐dimensional porous structure ensures that CNTs can be added at a high content and uniformly dispersed in epoxy resin. PANI adjusts the impedance matching of Buckypaper and adds more loss mechanisms. Under the optimal matching thickness of 1.5 mm, the optimal reflection loss reaches −29.31 dB, and the absorption bandwidth is 3.12 GHz. At the same time, the interaction between the π–π noncovalent bond of PANI and the delocalized π electrons on the surface of CNTs improves the mechanical strength of Buckypaper. The tensile strength reached 42.17 MPa, an increase of 92.82% compared with pure BP/EP. The research in this article is expected to provide a feasible idea for the preparation of structure–function integrated materials. [ABSTRACT FROM AUTHOR]

The self-restacking of graphene nanosheets inevitably compromises the electrochemical performance of conventional graphene-based materials. Herein, to solve this problem, we prepared a new type of three-dimensional porous aerogel with partially unzipped multiwalled carbon nanotubes inserted into graphene nanosheets via a reduction-reaction-induced self-assembly process. In the resulting aerogels, the inner carbon nanotubes (CNTs) tightly attach to the unzipped outer graphene nanoribbons (GNRs), which bridge with the graphene nanosheets. These interconnections bring them excellent electrical contact; the CNTs act as spacers to prevent the restacking of adjacent graphene nanosheets, and the abundant interconnected pores in the aerogels provide large channels for charge transfer. Accordingly, the aerogels exhibit a specific capacitance of 348.4 Fg−1 at a scan rate of 5 mVs−1, with capacitance retention remaining at 89.7% at a current density of 2 Ag−1 after 5000 cycles. The results show that the aerogels are promising electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Herein, polyaniline (PANI)/sulfonated graphene (SG) hierarchical composites was prepared through the growth of polyaniline nanorods on the surface of SG. The morphology and structure of the composites were analyzed by scanning electron microscopy, fourier transform infrared spectroscopy, raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. It was found that SG was beneficial to the form of uniform PANI nanorods, and strong interactions could be formed between them. Due to the synergistic effect between PANI and SG, The SG/PANI composite electrode exhibited excellent electrochemical performances, especially extraordinarily high-rate capability. When the current density increased to 50 A g−1, SG/PANI with 81.5% PANI presented a high specific capacitance of 477.5 F g−1, which remained 86.3% of its initial value at 0.5 A g−1. The cycle life test show the composites have excellent stability (still remain 96.7%) after 2000 cycles. Moreover, an asymmetric supercapacitor was assembled coupling with graphene, which demonstrated remarkable specific energy density and power density simultaneously. The highest values could achieve 56.34 Wh kg−1 and 1200 W kg−1. [ABSTRACT FROM AUTHOR]

A conducting copolymer of 1,1′-ferrocenediacyl anilide and aniline (P(FcA-co-ANI)) was synthesized, which had a conjugated structure and ferrocene moieties in the main chain. The monomer and copolymer were characterized using proton nuclear magnetic resonance and Fourier-transform infrared (FTIR) spectroscopies. A P(FcA-co-ANI)/reduced graphene oxide (rGO) composite was synthesized by oxidation polymerization, using rGO as a substrate. The characteristic peaks of P(FcA-co-ANI) and rGO were observed in the FTIR spectrum of P(FcA-co-ANI)/rGO. The X-ray diffraction pattern of P(FcA-co-ANI)/rGO exhibited similar peaks to the pattern of P(FcA-co-ANI), except for the absence of the weak broad peak at 9.0° owing to rGO. The surface morphologies of the materials were characterized by atomic force microscopy, transmission electron microscopy and scanning electron microscopy. The interlayer distances of rGO and P(FcA-co-ANI)/rGO were 0.96 and 1.38 nm, respectively. The morphology of the copolymer was spherical, and it contained island structures covering the surface of the graphene layers. The electrochemical properties of the composite were measured by cyclic voltammetry, galvanostatic charge–discharge measurements and electrochemical impedance spectroscopy. The maximum specific capacitance of the composite was 722.5 F/g at 0.5 A/g. The diffusion resistance was very small, and the composites durability was sufficient for subjecting to prolonged oxidation and reduction. [ABSTRACT FROM AUTHOR]

CeO 2 grafted polydopamine-wrapped graphene (G@PDA-CeO 2) was prepared by the layer-by-layer assembly to enhance the anticorrosive property of the epoxy resin. Electrochemical measurement results show that embedding 0.5 wt% of G@PDA-CeO 2 in the epoxy resin can effectively protect metal substrates for up to 56 days. After being immersed in a 3.5% NaCl solution for 56 days, its impedance modulus at 0.01 Hz is still as high as 1.360 × 108 Ω cm2, which is 2 orders of magnitude higher than pure epoxy resin coating. In addition, the scratch immersion test results show that the composite coating embedded with 0.5 wt% G@PDA-CeO 2 has excellent corrosion inhibition. Such excellent anticorrosive property is attributed to the synergistic effect of graphene's outstanding barrier effect, polydopamine's improved dispersibility, and CeO 2 's efficient corrosion inhibitory effect and weak hydrophilicity. This research provides a promising strategy for the preparation of long-term corrosion-resistant graphene-based polymer anticorrosive coatings. • G@PDA-CeO 2 with high impermeability can hinder the diffusion of the corrosive media. • G@PDA-CeO 2 avoids electrical contact with the steel substrate and inhibits galvanic corrosion. • G@PDA-CeO 2 owns dual anti-corrosion effects of barrier and corrosion inhibition. • G@PDA-CeO 2 /EP coating delivered an excellent protective property over a long period. [ABSTRACT FROM AUTHOR]

Graphene(RGO)//[N-butyl-3,6-carbazolevinylene-alt-(2,5-dioctyloxy)-p-phenylenevinylene] (PPH-CAR) ternary nanocomposite is fabricated by a simple two-step method, which includes electrochemical reduction of graphene oxide (GO) and oxidation of simultaneously and an ultrathin PPH-CAR layer coated on the RGO/ surface. The structure of the composite is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM). The results suggest that the composite is correctly synthesized and each component has good dispersion. Cycle voltammetry (CV), charge and discharge measurements and cycle stability test are used to evaluate its electrochemical performance. Because of the synergistic effect of each component, the composite exhibits excellent electrochemical properties with specific capacitance of 175 F/g, which is a 46% increase compared with RGO/. Moreover, it reveals outstanding cycling performance with more than 90% capacitance retention over 1000 cycles. Such ternary composite is a candidate for high performance supercapacitors with great promise. RGO/MnO2/PPH-CAR ternary nanocomposite was successfully fabricated via a simple two-step method. The electrochemical performance of the composite was measured and the results show great improvement in conductivity, specific capacitance and Nyquist impedance. It is indicating that the conducting polymer offers interparticle connectivity and facilitates electron transport among each component. The improved electrochemical properties of the composite are attributed to the synergistic effect of each component and this kind of ternary composite is a promising candidate for high performance of electrochemical supercapacitors. [ABSTRACT FROM AUTHOR]

• G@PpPD/PVB coating with a dense configuration was realized. • G@PpPD with extremely low conductivity can suppress the corrosion-promotion effect. • G@PpPD with high impermeability can hinder the diffusion of the corrosive media. • G@PpPD/PVB coating delivered an excellent protective property over a long period. Graphene (G) is an excellent protection material, but suffering corrosion-promotion effect because of its intrinsic high electrical-conductivity. Herein, a facile strategy is presented to effectively lower the conductivity of the G by the encapsulation of insulating poly(p-phenylenediamine) (PpPD). The obtained G@PpPD, which delivers an extremely low conductivity of 3.5×10−7 S cm-1, were then mixed with polyvinyl-butyral (PVB), forming a compact composite coating that can effectively protect Q235 steel from being corroded over a very long period. Such a superior anticorrosion property can be owing to the synergistic effect between impermeable graphene and insulated PpPD, which not only hinders the diffusion of the corrosive media, but also inhibits the corrosion-promotion activity of the graphene. This effective strategy may provide valuable enlightenment for the further development of graphene-based polymer anticorrosive coatings with long-lasting corrosion resistance. [ABSTRACT FROM AUTHOR]

• Due to the negative potential of NQDS, it can generate electrostatic reaction with Co2+. NQDs directed Co(OH) 2 growth, the amount of NQDs determines the density of rod-shaped cobalt hydroxide. • Fabrication of Cobalt hydroxide/N doped graphene quantum dots (Co(OH) 2 /NQDs) composites with chrysanthemum-shaped by an in-situ reaction. • the strong coupling between NQDs and Co(OH) 2 creates new electron transfer channels (Co-N), the Co(OH) 2 /NQDs composites delivers enhanced specific capacitance of about 593 F g−1 at 1 A/g. • The hybrid supercapacitor device based on Co(OH) 2 /NQDs composite and graphene aerogel exhibits a high energy density of about 33 Wh kg−1 at power density of 800 Wkg−1 and it retain about 137% specific capacitances after 8000 cycle test. NQDs can stabilize cobalt hydroxide after long cycles. Cobalt hydroxide is expecting electrode material for high-performance supercapacitors, however, it is still a challenge to improve its lack of transmission track and active sites. An effective method to improve the electrochemistry performance of cobalt hydroxide is to couple it with graphene quantum dots. Herein, we report the preparation of Cobalt hydroxide/N doped graphene quantum dots (Co(OH) 2 /NQDs) composites and study the electrochemistry performance of Co(OH)2/NQDs composites as supercapacitors electrode materials. Benefit from the strong coupling between NQDs and Co(OH) 2 creates new electron transfer channels (Co-N). The hybrid supercapacitor device based on Co(OH) 2 /NQDs composite and GA shows a high energy density of about 33.6 Wh kg−1 at a power density of 800 Wk g−1, and it retains about 137% specific capacitances after 8000 cycle test. Due to the negative potential of NQDS, it can generate an electrostatic reaction with Co2+, which can stabilize cobalt hydroxide after long cycles. [ABSTRACT FROM AUTHOR]