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Abstract Flexible electrodes with light weight, favorable mechanical strength and high energy/power density have attracted tremendous interest for next-generation lithium-ion batteries. Here we develop a novel architecture for preparing a freestanding binder-free flexible electrode (Hierarchical SnS 2 Nanoplates Decorated on the Graphene Supported by Carbon Cloth), which possesses superhigh mass-loading and large specific surface area. The electrode provides the high-rate transportation of electrolyte ions and electrons throughout the electrode matrix and buffers the volumetric expansion effect generated from Li+ insertion/desertion. The uniform size and homogeneous SnS 2 nanoplates on the graphene nanosheets reduced electrode polarization, leading to excellent electrochemical performance. The flexible electrode exhibits an extraordinary initial capacity of 1987.4 mAh g−1, a specific capacity up to 638.1 mAhg−1 after 150 cycles, which integrates that the design strategies to enhance the mass loading of active materials can be responsible for the superior lithium storage performance. Highlights • An insight into design for binder-free SnS 2 /graphene/carbon cloth flexible electrodes. • The electrodes possess larger specific surface area and higher mass loading. • The hierarchical SnS 2 and cross-linking graphene accelerate the transportation of ions and electrons. • The optimized anodes exhibit high specific capacity and stable cycling performance. [ABSTRACT FROM AUTHOR]

Three-dimensional graphene@carbon nanotube (G@CNT) composite was coated on polypropylene separator as an interlayer for high performance of lithium-sulfur batteries. In this study, the novel G@CNT nanotubes coated separator offers not only fast electron pathway for insulating sulfur, but also outstanding restriction of dissolving polysulfides. The heat impregnation of sulfur in carbon black also plays an auxiliary role on the cycling performance of the G@CNT interlayer assisted cathodes. As the dual sulfur locking strategy by heat impregnation and G@CNT interlayer, the prepared Li-S cells exhibited high rate capacity and sustainably enhanced cycling stability. Excellent cycling performance with a high capacity 935.1 mAh g −1 at 0.2C and 755.6 mAh g −1 at 1C after 200 cycles is achieved. Moreover, the cell delivers reversible discharge capacities up to 669.7 mAh g −1 and 555.1 mAh g −1 after 200 cycles even at 2C and 4C. [ABSTRACT FROM AUTHOR]

In this paper, we report the original synthesis of hollow Si-Ni 3 Sn 2 @ graphene composite and its high reversible capacity as lithium-ion battery anodes. To build the new architecture, three strategies of hollow architectures, porous surface and specific composition of graphene are attempted to develop lithium storage with far greater energy density and outstand rate performance. The results show that as-designed hollow Si-Ni 3 Sn 2 @graphene composites exhibit outstanding reversible capacity of 855.7 mAh g −1 during the first cycle, and 576.6 mAh g −1 can be maintained during a cycling test of 50 cycles at 300 mA g −1 . The rate capability is also enhanced, delivering reversible capacity of 449.8, 420.4, 392.7 and 377.1 mAh g −1 at current densities of 600, 800, 1200 and 1800 mA h g −1 , thus exhibiting great potential as an anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

High-performance electromagnetic wave absorption materials with strong absorption intensity, broad bandwidth, low density and thin thickness can be widely applied in the civil and military areas. In this paper, FeNi 3 nanoalloy decorated on 3D architecture composite of reduced graphene oxide/molybdenum disulfide (FeNi 3 @RGO/MoS 2 ) was prepared by two-step of hydrothermal reaction. RGO/MoS 2 composite was synthesized by a hydrothermal process and then FeNi 3 nanoalloy was decorated on the RGO/MoS 2 nanosheets via the second hydrothermal process. Electromagnetic wave absorption performances of FeNi 3 @RGO/MoS 2 composite with different filler loadings in paraffin matrix were investigated for the first time and it improves significantly with the increase of filler loading. The maximum absorption bandwidth is 4.72 GHz with the thickness of 2.0 mm and the corresponding reflection loss value is −30.39 dB when the filler loading of FeNi 3 @RGO/MoS 2 is 40%. The ternary composite possesses dielectric loss and magnetic loss in the testing frequency region, magnetic loss plays an important role in low-frequency region and dielectric loss occupies the main part in the high-frequency area. [ABSTRACT FROM AUTHOR]

Flower-like NiFe 2 O 4 decorated on 2D graphene nanosheets composite and spherical NiFe 2 O 4 decorated on 2D graphene nanosheets composite have been synthesized through an easy method including one-pot hydrothermal route and one-pot heat treatment, respectively. In the well-designed 3D dimensional system, 2D graphene nanosheets work as conductive matrix to support the flower-like NiFe 2 O 4 and spherical NiFe 2 O 4 . The structure integrates the advantage of graphene nanosheets to preserve the electrode activity and integrity, improving the electrochemical performance. Lithium storage properties of the two kind of composites are compared as anode materials. The results presented that flower-like NiFe 2 O 4 /graphene composite shows better electrochemical performance and cycling stability. The first discharge capacity is 2632.6 mA h/g at a high current density of 100 mA/g. After 50 cycles, the reversible capacity is 606.2 mA h/g and the coulomb efficiency reaches at 98.86%. With the excellent electrochemical properties, flower-like NiFe 2 O 4 decorated on 2D graphene nanosheets could be a kind of promising potential candidate anode materials for LIBs. This research offers possibility to improve the lithium ion storage capacity of transition metal oxides through advisablely controlling the architecture and composition of anode materials. [ABSTRACT FROM AUTHOR]

The novel sandwich structures of graphene@Fe 3 O 4 @PANI decorated with TiO 2 nanosheets were firstly successfully prepared by simple hydrothermal method and in situ polymerization. VSM results reveal that the nanocomposites have a superparamagnetic behavior. Structure and morphology were characterized by X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. Electron microscopy images show that TiO 2 nanosheets are mostly grown upright on the top of graphene@Fe 3 O 4 @PANI support with a random orientation, and form hierarchical structures. Electromagnetic (EM) wave absorption properties of graphene@Fe 3 O 4 @PANI@TiO 2 nanosheets containing 50wt% paraffin were investigated in the frequency region of 2–18 GHz. The maximum reflection loss of the nanocomposites is up to −41.8 dB at 14.4 GHz with a thickness of 1.6 mm, and the absorption bandwidth of R L < −10 dB is almost up to 3.5 GHz. Thus, the enhanced EM wave absorption properties of graphene@Fe 3 O 4 @PANI@TiO 2 nanosheets can be used as promising EM wave absorbers. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide (RGO)/cobalt ferrite (CoFe 2 O 4 ) composites with three different (RGO)/(CoFe 2 O 4 ) ratios were synthesized by a one-pot hydrothermal route. To research the influence of graphene reduction degree on electromagnetic parameters of graphene composites, RGO/CoFe 2 O 4 -2 was treated further by reduction process with different reducing agents (N 2 H 4 /NaBH 4 ). The crystalline structure, morphology, thermal stability, magnetic property of the synthesized samples were characterized by XRD, TEM, SEM, FT-IR, Raman, TG, VSM and XPS. The absorption properties of the RGO/CoFe 2 O 4 composites were studied. The maximum R L of RGO/CoFe 2 O 4 -2 composite is −47.9 dB at 12.4 GHz with a thickness of 2.3 mm, and the absorption bandwidth with the R L below −10 dB is up to 5.0 GHz (from 12.4 to 17.4 GHz) with a thickness of 2.0 mm. The results indicated that the RGO/CoFe 2 O 4 composites have remarkably electromagnetic performance, which are attributed to effective complementarities between the dielectric loss and the magnetic loss. Additionally, the microwave absorption properties of the RGO/CoFe 2 O 4 composites can be tuned easily by varying the (RGO)/(CoFe 2 O 4 ) ratio, the reduction degree of graphene and layer thickness of the samples. [ABSTRACT FROM AUTHOR]

The electromagnetic wave absorption properties of the ternary nanocomposites consisting of graphene, poly (3,4-ethylenedioxythiophene) and Fe 3 O 4 nanoparticles had never been reported. Herein, in order to expand the scope of electromagnetic wave absorption materials, the nanostructured graphene/poly (3,4-ethylenedioxythiophene) hybrid materials with Fe 3 O 4 nanoparticles had been synthesized by a controllable co-precipitation method. The nanocomposites were characterized by FTIR, XRD, TEM, Raman spectroscopy, XPS and TG analysis. The investigation of the electromagnetic parameters revealed that the excellent electromagnetic wave absorption properties of the nanocomposites may be attributed to the improved impedance matching, the enhanced interfacial effects and the geometric effect. The maximum reflection loss of the nanocomposites was up to −56.5 dB at 8.9 GHz and the absorption bandwidths exceeding −10 dB were 3 GHz with a thickness of 2.9 mm. Furthermore, our development strategies expanded the scope of the electromagnetic wave absorption materials and confirmed that the modification of graphene with poly (3,4-ethylenedioxythiophene) and Fe 3 O 4 nanoparticles makes the nanocomposites have a promising future in electromagnetic wave absorption materials. [ABSTRACT FROM AUTHOR]

Highlights: [•] The ternary nanocomposites of GN–PANI–Fe3O4 were synthesized via a two-step method. [•] The size of Fe3O4 nanoparticles on GN–PANI is in the range of 5–20nm. [•] The maximum RL of GN–PANI–Fe3O4 is −43.9dB at 11.4GHz with a thickness of 2.5mm. [•] All the maximum RL was less than −24.2dB when the thicknesses vary from 2 to 4mm. [•] The bandwidths exceeding −10dB are 11.0GHz when the thicknesses in 2–4mm. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) with a honeycomb arrangement were designed onto graphene as the electrochemical electrodes. The honeycomb arrangement provided a relatively larger surface area to store more ions with a stronger structure to maintain long-term surface morphology. The combination of CNTs and graphene exhibited robust durability during electrochemical performance. The pseudo-capacitive property of IrO 2 was coated onto the CNT surface to enhance the capacitance. Cyclic voltammetry and charging–discharging measurements were used to examine the electrochemical behaviors. The CNTs/graphene and IrO 2 /CNTs/graphene capacitances were 3.93 and 129.40 F/g, respectively. The designed electrode demonstrates excellent characteristics and is appropriate for electrochemical applications. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2 ) films are currently the most potential semiconductor materials of the two-dimensional nano-material heterojunction. Few-layer MoS 2 is an n-type semiconductor that has good mechanical strength, high carrier mobility, and has similar thickness as graphene. Graphene is presently the thinnest two-dimensional material with good thermal conductivity and high carrier mobility. The graphene Fermi level can be precisely controlled using the oxygen adsorption. Therefore, graphene can be tuned from zero-gap to p-type semiconductor material using the amount of adsorbed oxygen. In this study we combine few-layer MoS 2 and graphene to produce a heterojunction and exhaustively study the interface properties for heterojunction diode application. According to the results, the MoS 2 band-gap increases with decreasing thickness. The I–V characteristics of the MoS 2 /Graphene p-n junction diodes can be precisely tuned by adjusting different thicknesses of the MoS 2 films. By applying our fabricating method, MoS 2 /Graphene heterojunction diode can be easily constructed and have potential to different applications. [ABSTRACT FROM AUTHOR]