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Although high-temperature solid-phase methods have become the dominant route for manufacturing layered oxide cathode materials in industry, severe Li+/Ni2+ cation mixing problems caused by high-temperature processes still prevent the realization of high-performance lithium-ion batteries. Herein, a wet chemical lithiation method by stepwise lithium intercalation to reduce and shorten the sintering temperature and time of the post-treatment process is proposed. Li 0.6 H x Ni 0.52 Co 0.19 Mn 0.29 O 2 stepwise products with lithiation efficiencies exceeding 60% were obtained at reaction temperatures below 200 °C. The as-prepared LiNi 0.52 Co 0.19 Mn 0.29 O 2 (HT-52-S) exhibits low Li+/Ni2+ cation mixing and good comprehensive electrochemical performance after subsequent heat treatment to complete all lithiation. Compared with LiNi 0.52 Co 0.19 Mn 0.29 O 2 (SS-52) prepared by the conventional high-temperature solid-phase method, the Li+/Ni2+ cation mixing of HT-52-S was relatively reduced by 57.9%, and the capacity retention after 100 cycles at 1 C was relatively improved by 22.1%. We believe that this work can serve as a useful reference to develop manufacturing processes for high-performance layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

The electric field-modulated photoluminescent (E -PL) effect has received much attention because of its potential applications in optical data storage and communication. Based on the E- induced antiferroelectric-ferroelectric (AFE-FE) phase transition, a large and reversible modulation of the PL intensity was previously realized in lanthanum-doped Pb(Zr 0.9 Ti 0.1)O 3 (PLZT) ceramics. However, such systems contain abundant leads and are thus toxic to humans and the environment. In this work, Er-doped AgNbO 3 (ANO) lead-free ceramics were prepared, and their E -PL effect was investigated. From the perspective of the crystallographic symmetry, the reversibly E -induced orthorhombic Pbcm to orthorhombic Pmc 2 1 transition results in a negative PL intensity change of 25%, which is different from the positive 30% PL modulation in the PLZT system triggered by the AFE-FE orthorhombic-rhombohedral phase transition. This symmetry-dependent negative PL modulation in ANO ceramics enriches the understanding of the E -PL effect in AFEs and provides an environmentally friendly alternative for multifunctional optoelectronics. [ABSTRACT FROM AUTHOR]

In this research, well-crystallized lithium chloride (LiCl) intercalated graphite carbonitride (g-C 3 N 4) nanotubes (LiCl–CN) as ceramic films have been rationally designed and fabricated through the molten salt preparation. The as-synthetic material exhibited nanotube morphology and showed significantly enhanced photocatalytic performance on the degradation of bisphenol A (BPA) compared with g-C 3 N 4 in the presence of simulated solar light. The catalytic performance of LiCl–CN was remarkably improved due to the structural alteration of g-C 3 N 4. The results demonstrated 100% BPA could be effectively removed with 0.3 g/L LiCl–CN at pH 5.0 in this investigated reactive system, and the degradation behavior was consistent with pseudo first order reaction kinetic model. Besides, LiCl–CN photocatalyst exhibited excellent photostability and recyclability for BPA photolysis. Mechanistic study revealed that both superoxide radicals (·O 2 -) and photogenerated holes (h+) were the dominant activated species for the degradation of BPA by LiCl–CN. The findings of this work further open an avenue for the application of g-C 3 N 4 based ceramics materials for organic pollutant removal from wastewater. Image 1 • LiCl–CN with enhanced visible light - driven photocatalytic active was rationally designed and fabricated. • BPA can be completely degraded by LiCl–CN nanotubes as ceramic films. • O 2 - and h+ are the main active species for BPA degradation by LiCl–CN. • LiCl–CN nanotubes processed remarkable stability and repeatability. [ABSTRACT FROM AUTHOR]

A simple preparation method of the anode is designed for sodium ion battery. The bimetallic selenide (CoSe 2 /ZnSe) and nitrogen-doped carbon composite materials are obtained by selenization and carbonization of the metal organic framework precursors, and applied to high-performance sodium ion storage. The ingenious nanostructure is shown in that CoSe 2 and ZnSe nanoparticles are evenly distributed on the fusiform flake carbon skeleton. This synergy can improve the capacity and conductivity, and inhibit the volume expansion during the cycle. For electrochemical performance analysis, the prepared 1:1-CoSe 2 /ZnSe@NCC electrode shows a high discharge specific capacity of 621.5 mA h g-1 at 0.1 A g-1 after 100 cycles (coulomb efficiency close to 100%, capacity retention reaches ~ 90%), and has advantages over other electrodes in terms of rate performance and reaction kinetics. The excellent electrochemical performance confirms the successful development of a high performance electrode for sodium ion storage by this strategy. [ABSTRACT FROM AUTHOR]

Thermal management of Al composites is a crucial issue to keep the promising performance and excellent reliability of the devices. We revealed a novel method to enhance the surface property of graphite flakes (GF) with Cu and Ni coatings by chemical plating way. Taking advantage of Cu and Ni co-doped GF and silicon powders, the GF@Cu@Ni/Si/Al composites were fabricated by vacuum pressure infiltration method. The GF@Cu-30@Ni-10 composites revealed about 2 times larger TC (474.4 W/m·K) and lower CTE 6.22 ppm/K than neat Al. Our strategy for highly TC offers not only the advanced process for dispersing reinforcements but also an extremely simple way for the anisotropic composites with high TC and low CTE. [ABSTRACT FROM AUTHOR]

As a core component of all-solid-state lithium batteries (ASSLBs), composite solid electrolytes (CSEs) have good safety, high ionic conductivity and certain flexibility. Here, we report that the CSEs is composed by mixing the Li 7 La 3 Zr 2 O 12 (LLZO) and Li 6.7 La 3 Zr 1.7 Ta 0.3 O 12 (LLZTO) ceramic filler, polyethylene oxide (PEO) and LiTFSI. The ionic conductivity of the optimized CSEs is as high as 1.7 × 10−4 S cm−1 at 30 °C, the electrochemical stability window is 5.4 V, and the lithium ion transference number is 0.5 at 60 °C. In addition, the uniform distribution of ceramic particles enhances the thermal stability, mechanical strength and the interfacial compatibility of the CSEs, which inhibits the growth of lithium dendrites. The assembled LiFePO 4 /PEO-LiTFSI-10 wt% Li 6.7 La 3 Zr 1.7 Ta 0.3 O 12 /Li battery exhibited excellent cycle and rate performance at 60 °C. The initial discharge capacity was 140 mA h g−1 at a current density of 0.2 C, and the discharge capacity was maintained 139.4 mA h g−1 after 200 cycles. [ABSTRACT FROM AUTHOR]

A novel electromagnetic (EM) wave absorber is synthesized by covalently modifying reduced graphene oxide (rGO) with Fe 3 O 4 @SiO 2 nanoparticles. The results show that after the amidation reaction, magnetic Fe 3 O 4 @SiO 2 nanoparticles are successfully linked to rGO via amide bonds. The EM wave absorption properties can be adjusted by changing the weight ratio of Fe 3 O 4 @SiO 2 to rGO. When the ratio is 1:1, the absorber exhibits outstanding absorption performance that the maximum reflection loss (RL) peaks achieve −55.4 dB at 8.48 GHz, −55.4 dB at 8.08 GHz and −52.5 dB at 7.2 GHz with matching thicknesses of 3.5 mm, 3.7 mm and 4.0 mm. The excellent absorption performance can be attributed to good impedance matching and superior attenuation ability. The introduction of amide bonds can act as carrier channels to promote the migration of electrons, change the electron cloud distribution of graphene and adjust EM parameters of absorbers to achieve excellent absorption properties. It provides a new approach to prepare high-efficiency EM wave absorbers. [ABSTRACT FROM AUTHOR]

Hollow and porous three-dimensional Co(Ni)Se 2 /N-doped carbon composite particles prepared by a simple process using metal organic framework (MOF) precursors as the template are used as a high-efficiency anode material for sodium ion batteries. The composite material having a regular rhombohedral dodecahedral structure contains the N-doped porous carbon shell and the nano-metal selenide (CoSe 2 and NiSe 2) embedded in the carbon shell. Moreover, the metal selenide has a high capacity density, and the N-doped porous carbon structure can enhance the electrical conductivity and structural stability of the material to suppress volume expansion. Their effective synergistic combination shows excellent electrochemical performance. As the anode of the sodium ion battery, Co(Ni)Se 2 @NCC exhibits a very high specific capacity of up to 735.2 mA h g−1 after 100 cycles and superior rate performance. In addition to these, excellent kinetic performance and cycle stability and coulombic efficiency are sufficient to prove that this material has broad prospects in sodium-ion battery anodes. [ABSTRACT FROM AUTHOR]

Ag 3 PO 4 /graphene oxide aerogel composites were fabricated by a hydrothermal method. The structure of Ag 3 PO 4 and graphene oxide aerogel was investigated by XRD and Raman spectrum. The specific surface area of Ag 3 PO 4 , graphene oxide aerogel, and Ag 3 PO 4 /graphene oxide aerogel composites was investigated by the BET method. The adsorption and photocatalytic properties of Ag 3 PO 4 /graphene oxide aerogel composites were studied in Methylene Blue solution. The results showed that the existence of graphene oxide aerogel among Ag 3 PO 4 could increase the specific surface area, adsorption performance, and photocatalytic performance of the composites. A higher percentage of graphene oxide aerogel resulted in higher adsorption capacity of Ag 3 PO 4 /graphene oxide aerogel composites, while an optimum percentage of graphene oxide aerogel was required for the maximum photocatalytic performance of the composites. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) flower-like Bi 2 SiO 5 nanomaterials (FLB) and 3D flower-like Bi 2 SiO 5 @nitrogen doped graphene nanomaterials (FLBNG) have been originally synthesized. Notably, as-synthesized FLB and FLBNG nanomaterials have not yet been discussed in previous reports. The FLBNG nanomaterials have been for the first time studied as the cathodic catalysts for Fuel cell. Research results have shown that the FLBNG-2 possesses perfectly 3D flower-like Bi 2 SiO 5 with numerous uniformly coiled nanowires and exhibits good methanol immunity, high activity and high durability during oxygen reduction reaction (ORR) process under acidic and basic electrolytes. The value of onset potential (E 0) for FLBNG-2 in alkaline electrolyte can reach to 1.091 V, Tafel slope of FLBNG-2 is 45.637 mV dec−1 and its limiting current density (J L) is 6.49 mA cm−2. Similarly, These ORR performances in acidic electrolyte are also better than those of 20 wt% commercial Pt/C and most of the associated reports. Thus, the FLBNG-2 could be a potential ORR catalyst, applied in the cathode of fuel cells to enhance the kinetic rate, decrease costs and enhance durability. And this synthesis method may be provide a good design to synthesize other 3D flower-like nanomaterials with desirable properties. [ABSTRACT FROM AUTHOR]

In this paper, synthesis of nitrogen and phosphorus co-doped 3D hierarchical porous carbon network (NP–CN) with superior electrochemical performance in sodium-ion battery anode material was reported. In terms of structure, 3D network structure can fully alleviate the stress generated during charging and discharging, while hierarchical porous structure provides more electron and ion transmission channels, which facilitates rapid transfer of charge. Meanwhile, doping of nitrogen and phosphorus can increase defect sites of material to promote sodium ion adsorption. In addition, nitrogen can enhance conductivity of material and phosphorus can be inserted into carbon lattice to enlarge interlayer spacing, beneficial to the intercalation and deintercalation of sodium ions. Based on above advantages, NP-CN possesses 315 mAh g−1 at 100 mA g−1 after 200cycles in sodium-ion battery. Furthermore, the method is simple and raw material is easy to obtain, making NP-CN have better practical value. [ABSTRACT FROM AUTHOR]

Bi 2 Mo 2 O 9 nanoparticles were introduced into bismuth antimony tellurium (BST) alloys by ball milling, and the composite particles were then fabricated into pellets by hot press for thermoelectric property measurement. Both elemental mapping and TEM image confirmed that Bi 2 Mo 2 O 9 nanoparticles were evenly distributed among BST matrix. The impacts of Bi 2 Mo 2 O 9 volume percentage on the electrical resistivity, Seebeck coefficient, thermal conductivity, and thermoelectric figure of merit (ZT) of BST/Bi 2 Mo 2 O 9 composites were investigated. The results told that the composite presented the highest thermoelectric ZT when Bi 2 Mo 2 O 9 was 0.3 vol%, which was increased by 12.15% from the ZT of pure BST at room temperature. This could be attributed to the balance between the decreased thermal conductivity and increased electrical resistivity, and phonons could are blocked when charge carriers passing through the dispersed Bi 2 Mo 2 O 9 nanoparticles. [ABSTRACT FROM AUTHOR]

Bi 2 MoO 6 and FePt particles were synthesized by hydrothermal and wet chemistry methods, respectively. Bi 2 MoO 6 /FePt composites were synthesized by milling, and their mass ratio was controlled. The photocatalytic performance was evaluated by degrading an organic dye. When FePt mass is 10%, the composite presented the best photocatalytic performance. The photocatalytic mechanism investigation indicated that the highest photocatalytic performance was attributed to the prevented electron/hole recombination because of the existence of FePt nanoparticles in Bi 2 MoO 6. The stability testing showed that Bi 2 MoO 6 /FePt-2 had relatively high reaction stability over reactions. The magnetic separation can be applied due to the presence of the magnetic phase of FePt in Bi 2 MoO 6 /FePt composites. [ABSTRACT FROM AUTHOR]

Carbon-doped ZnCo 2 O 4 (ZnCo 2 O 4 /C) yolk-shell microspheres are synthesized by a method of thermally decomposing precursor and then successfully compounded with magnetic graphene (MG) via co-precipitation in combination with a reduction pathway. The fabrication processes and characterizations (XRD, XPS, TEM, EDS and SEM) are described and explained in detail. It is confirmed that amorphous carbon (in situ decomposition from PVP) is uniformly doped into ZnCo 2 O 4 yolk-shell microspheres. In addition, the reflection loss (RL) and electromagnetic (EM) wave absorption mechanisms of as-prepared ZnCo 2 O 4 /C/MG composites are calculated and analyzed exhaustively. The results show that absorption bandwidth with RL exceeding −10 dB reaches up to 4.48 GHz with a matching thickness of 3.5 mm while the maximum RL is up to −52.9 dB at 7.52 GHz with a matching thickness of 3.9 mm. Enhanced EM wave absorption performance can be attributed to good dielectric and magnetic loss, excellent impedance matching, diverse interfacial polarization and multiple reflections caused by special structures. [ABSTRACT FROM AUTHOR]

Hybrid transitional metals oxides have been attracted more and more attention in the field of supercapacitors. However, the design of structure and composition of materials is always a challenge due to tedious preparation process and difficult structure construction. Based on above issue, we construct novel raspberry-like Ni/NiO/CoO/Mn 3 O 4 hierarchical structures (NNCMs) with excellent electrochemical performances by one-step hydrothermal process in this work. The introduction of metallic Ni and well-designed hierarchical structures can result in well improved conductivity for electrode material, sufficient channels and active sites for electrolyte ions to enter and contact with electrode material. The NNCMs-16 electrode exhibits a high specific capacitance of 1964 F g−1 and superior cycling stability (95% of initial specific capacitance after 10000 cycles). The assembled NNCMs-16//AC device delivers outstanding energy densities of 70.4 Wh kg−1 at power densities of 794.5 W kg−1. Thus, the raspberry-like NNCMs-16 hierarchical structures can be regarded as promising materials for practical supercapacitors and this work also provides a valuable reference for the preparation and application of high performance electrode materials. [ABSTRACT FROM AUTHOR]

Reasonable design of multi-component metal oxides hierarchical nanostructures is an effective and promising way to improve electrochemical performances of electrode materials. In this work, novel hydrangea-like ZnCo 2 O 4 /Ni 3 V 2 O 8 hierarchical nanostructures are constructed by adjusting the ratio of ZnCo 2 O 4 and Ni 3 V 2 O 8. The perfect architecture maximizes the synergistic effect between different components and provides abundant electrochemical reactive sites, promoting the diffusion and transfer of electrolyte ions in electrochemical reaction process. As a result, ZnCo 2 O 4 /Ni 3 V 2 O 8 electrodes deliver an enhanced specific capacitance of 1734 F g−1 at 1 A g−1 and cyclic stability (96% of initial capacitance is retained after 8000 cycles). Furthermore, the assembled ZnCo 2 O 4 /Ni 3 V 2 O 8 //AC device e achieves excellent energy density of 90 Wh kg−1 at power density of 812 W kg−1, proving the optimized hydrangea-like ZnCo 2 O 4 /Ni 3 V 2 O 8 hierarchical nanostructures are promising electrode material for supercapacitor. In addition, this work supplies helpful insights into rational design of structure and composition of multi-component metal oxides for enhanced electrochemical performance. [ABSTRACT FROM AUTHOR]

Abstract Surface modification with noble metal cocatalysts was proved to be a useful route for boosting photocatalytic efficiency of various photocatalysts. Nevertheless, considering the random dispersion of metallic cocatalysts on the photocatalyst surface, the noble metal-loaded photocatalyst generally shows a limited enhancement of its activity because the noble metals can also work as the recombination sites of photoinduced charges. In this paper, TiO 2 as a dual-function mediator (for effective electron transport and hole block) is successfully introduced into the interface of Pt and CdS to form Pt TiO 2 /CdS photocatalyst, with an aim of suppressing the high recombination rate of electron-hole pairs on the Pt active sites. Under visible light, all the prepared Pt TiO 2 /CdS displayed distinctly enhanced photocatalytic hydrogen-generation performance and the Pt TiO 2 /CdS(8%) attains the highest photocatalytic H 2 -production rate (294.2 μmol/h), a value significantly higher than that of Pt/CdS about 3.2 time. A dual-function TiO 2 -mediated mechanism was put forward to account for the superior hydrogen production of Pt TiO 2 /CdS photocatalyst, namely, the TiO 2 layer in the Pt TiO 2 /CdS not only works as electron-transport layers to effectively transfer photogenerated electrons to promote the H 2 -production reaction on Pt cocatalysts, but also acts as hole-block layer to prevent the possible recombination of photogenerated charges on the Pt active sites, resulting in a distinct improvement of final H 2 -generation activity. [ABSTRACT FROM AUTHOR]

Abstract In this research, the nanocomposites, CoNi/SiO 2 core-shell nanoparticles decorated reduced graphene oxide (RGO) nanosheets, are successfully synthesized via liquid-phase reduction reactions combined with a sol-gel route. The structures, morphologies, chemical composition and magnetic properties of CoNi nanoparticles, CoNi/SiO 2 core-shell nanoparticles and RGO/CoNi/SiO 2 nanocomposites have been investigated in exhaustive detail. The electromagnetic (EM) parameters of RGO/CoNi/SiO 2 nanocomposites are measured using a vector network analyzer. The results reveal that the RGO/CoNi/SiO 2 nanocomposites display enhanced EM wave absorption properties with the maximum reflection loss (R L) of − 46.3 dB at 6.2 GHz with a matching thickness of 4.2 mm. Additionally, the absorption bandwidth corresponding to the R L less than − 10 dB is up to 14.3 GHz (3.7–18.0 GHz) with a matching thickness range of 2.0–5.0 mm. To comprehensively consider the absorption bandwidth and the maximum R L , the integrational method which defines ΔS as the integration area of R L (R L < − 10 dB) and R E as EM wave absorption efficiency is adopted to reveal that the RGO/CoNi/SiO 2 nanocomposites exhibit the excellent absorption properties with the matching thickness of only 2.0 mm. Accordingly, the as-prepared RGO/CoNi/SiO 2 nanocomposites could be applied as promising EM wave absorption materials. [ABSTRACT FROM AUTHOR]

Abstract In this work, an eco-friendly and convenient microwave-assisted synthesis technique was applied in the entire experiment course. The first obtained graphene-Ni composite possess an unsatisfactory microwave absorption capacity due to unbalanced matching nature. Then a sulfurization process was tried at different temperatures to convert Ni into NiS/Ni 3 S 2 , and an innovative graphene-NiS/Ni 3 S 2 composite with a hierarchical architecture was fabricated under the condition of microwave irradiation. The investigation into microwave absorbing performances manifests that the absorption property of graphene-Ni can be obviously improved by sulfurization method. The results show, compared with graphene-Ni, the hierarchical-architecture graphene-NiS/Ni 3 S 2 composites generated at 150 ℃ (S-150) possess excellent absorbing ability with a maximum RL as strong as − 55.1 dB at 6.0 GHz with a thickness of 2.7 mm, and the effective bandwidth covers 8.6 GHz from 2.8 to 11.4 GHz with thickness varies in 1.5–4.5 mm range. The enhanced performances for S-150 mainly derive from the synergy of superior impedance matching character, high attenuation, dielectric loss and plenteous interface polarizations. [ABSTRACT FROM AUTHOR]

Abstract Binding-free NiCo 2 O 4 @NiO@C/cc electrode was prepared by hydrothermal method, annealing method and physical vapor deposition. In this composite, NiCo 2 O 4 @NiO was strongly grown on carbon cloth and formed a core-shell heterostructure, which can facilitate the transport of ions. What's more, the conductivity was dramatically improved after coating NiO nanofalkes. Additionally, carbon coating can inhibit volume expansion, improve material conductivity and structural stability. The free-standing electrode material showed an initial capacity of 1885 mAh g−1 at a current density of 100 mA g−1, after 100 cycles, the reversible capacity stabilized around 1051 mAh g−1 with Coulomb efficiency of 99.9%. At a high rate of 1600 mA g−1, the capacity exhibited about 721 mAh g−1, indicating that the NiCo 2 O 4 @NiO@C/cc composite is an outstanding material as the anode electrode material for flexible lithium-ion batteries with broad application prospect. [ABSTRACT FROM AUTHOR]

The core-shell ZnFe 2 O 4 @SiO 2 hollow microspheres/reduced graphene oxides (RGO-ZnFe 2 O 4 @SiO 2 ) composites were successfully synthesized by a rational process. SEM and TEM results illustrate that the ZnFe 2 O 4 @SiO 2 hollow microspheres are of core-shell structure with an average diameter of about 1 µm mixed with graphene sheets. Compared with ZnFe 2 O 4 @SiO 2 hollow microspheres and RGO-ZnFe 2 O 4 composites, the as-prepared RGO-ZnFe 2 O 4 @SiO 2 composites exhibit excellent electromagnetic (EM) wave absorption properties in terms of both the maximum reflection loss and the absorption bandwidth. The maximum reflection loss of RGO-ZnFe 2 O 4 @SiO 2 composites is −45.8 dB at 7.6 GHz with the thickness of 3.7 mm and the absorption bandwidth with the reflection loss below −10 dB is up to 14.5 GHz (from 3.5 to 18.0 GHz) with a thickness in the range of 2.0–6.0 mm. It may also be stressed that the developed composites cover the whole X band (8.0–12.0 GHz), which could be used for military radars and direct broadcast satellites (DBS). [ABSTRACT FROM AUTHOR]

A magnetic reduced graphene oxide (MRGO) composite consisting of graphene oxide and Fe 3 O 4 particles in the range of 5–20 nm has been prepared by the one-pot hydrothermal process. RGO nanosheets provide flexible substrates for nanoparticle decoration, while Fe 3 O 4 nanoparticles can also effectively prevent nanosheets to restack each other. Compared with previously literature, the synthesized RGO-Fe 3 O 4 composite exhibits excellent electromagnetic wave absorption. The minimum reflection loss (R L ) value of −49.05 dB has been observed at 14.16 GHz with a thickness of 2.08 mm. The absorption bandwidth (R L <−10 dB) corresponding to the minimum R L is 4.60 GHz. The electromagnetic wave absorption properties of the RGO-Fe 3 O 4 composite have been interpreted through the quarter-wavelength matching model. [ABSTRACT FROM AUTHOR]

In this work, hierarchical Carbon sphere@NiMoO 4 (C@NiMoO 4 ) composite was successfully synthesized by cost-effective two-step hydrothermal method. The samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis and Thermogravimetric analysis. The Electrochemical measurement demonstrated that hierarchical C@NiMoO 4 electrode materials exhibited good specific capacitance (Csp) of 268.8 F g −1 at a current density of 1 A g −1 in 2 M NaOH aqueous electrolyte solution, as well as good cycling stability (88.4% retention after 2000 cycles). Compared to pure NiMoO 4 , the excellent capacitive properties and stability suggest that the hierarchical structure C@NiMoO 4 could be promising electroactive material for supercapacitors. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide (RGO)/CoFe 2 O 4 /SnS 2 composites have been successfully synthesized by two-step hydrothermal processes. TEM results show that CoFe 2 O 4 and SnS 2 nanoparticles with both diameters about 5–10 nm are well dispersed on the surface of graphene. Compared with RGO/CoFe 2 O 4 composites, the as-prepared RGO/CoFe 2 O 4 /SnS 2 composites exhibit excellent electromagnetic (EM) wave absorption properties in terms of both the maximum reflection loss and the absorption bandwidth. The maximum reflection loss of RGO/CoFe 2 O 4 /SnS 2 composites is −54.4 dB at 16.5 GHz with thickness of only 1.6 mm and the absorption bandwidth with the reflection loss below −10 dB is up to 12.0 GHz (from 6.0 to 18.0 GHz) with a thickness in the range of 1.5–4.0 mm. And especially, they cover the whole X band (8.0–12.0 GHz), which could be used for military radar and direct broadcast satellite (DBS). [ABSTRACT FROM AUTHOR]

Flower-like ZnO–NiO mesoporous architectures were synthesized through annealing the zinc hydroxide carbonate–nickel hydroxide carbonate composite precursor, which was prepared via a one-pot hydrothermal route. More importantly, we successfully prepared flower-like porous ZnO–NiO/graphene composites by introducing flexible graphene into the flower-like porous ZnO–NiO. In addition, we explore the application of the 3D flower-like ZnO–NiO composite mesoporous architectures and flower-like porous ZnO–NiO/graphene composites as anode materials for lithium ion battery. Electrochemical study presented that the as-prepared flower-like porous ZnO–NiO/graphene composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 1205.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 452.7 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 99%.The improved electrochemical performances are mainly attributed to its morphological characteristics of mesoporous, nanosheet self-assembling architectures, as well as the addition of graphene. These results suggest that such 3D flower-like porous ZnO–NiO/graphene composites are promising materials for lithium ion battery. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) graphene@CNTs@MnO 2 (GCM) nanocomposites materials have been fabricated by a facile two-step method. The structure, morphology and electrochemical properties of the 3D nanocomposites were investigated by XRD, TG, Raman, SEM, TEM and electrochemical measurements. The 3D forest-like rGO@CNTs (GC) serves as both the backbone and ideal electron pathway for MnO 2 . With this sophisticated configuration, the 3D GCM nanocomposites exhibit a specific capacitance of 245 F g −1 at 0.5 A g −1 , excellent cycling stability (91.4% retention after 2000 cycles at 1 A g −1 ) and high rate capability. These excellent capacitive performances may make the as-prepared nanocomposites as promising electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

Graphene supported porous Si@C ternary composites had been synthesized by various routes and their structural, morphological and electrochemical properties were investigated. Porous Si spheres coated with carbon layer and supported by graphene have been designed to form a 3D carbon conductive network. Used as anode materials for lithium ion batteries, graphene supported porous Si@C ternary composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 2184.7 mA h/g at a high current density of 300 mA/g. After 50 cycles, the reversible capacity is 652.4 mA h/g at a current density of 300 mA/g and the coulomb efficiency reaches at 98.7%. Due to their excellent electrochemical properties, graphene supported porous Si@C ternary composites can be a kind of promising anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: Flower-like Zn2SnO4 composites had been prepared through a green hydrothermal synthesis. The structural, morphological and electrochemical properties were investigated by means of XRD, BET, SEM, TEM, and electrochemical measurement. The results show that the as-prepared sample is in high purity phase and of good crystallinity; meanwhile it has a particular 3-D structure and large surface area. Electrochemical measurement suggests that flower-like Zn2SnO4 composites exhibit better cycling properties and lower initial irreversible capacities than the solid Zn2SnO4 cubes. The first discharge and charge capacities of the material are 1750mAhg−1 and 880mAhg−1 respectively. A higher reversible capacity of 501mAhg−1 was obtained after 50 cycles at a current density of 300mAg−1. The higher reversible capacity and good stability can be related to the special nanostructural features of the material. Such Zn2SnO4 structures synthesized by the simple and cheap method are expected to have potential application in energy storage. [Copyright &y& Elsevier]

Abstract: The reduced graphene oxide (RGO)/NiFe2O4 composite was synthesized by a facile one-pot hydrothermal route, which avoided the usage of chemical reducing agent. The reduction of graphene oxide (GO) and the crystallization of NiFe2O4 crystals happened in a one-step hydrothermal process. The morphology, microstructure and magnetic properties of the composite were detected by means of XRD, XPS, TEM, EDX, TG-DSC and VSM. The maximum R L of the RGO/NiFe2O4 composite is −39.7dB at 9.2GHz with the thickness of 3.0mm, and the absorption bandwidth with the R L below −10dB is up to 5.0GHz (from 12.7 to 17.7GHz) with a thickness of 1.9mm. The introduction of RGO signally enhanced microwave absorption performance of the NiFe2O4 NPs. It is believed that such composite will be applied widely in microwave absorbing area. [Copyright &y& Elsevier]

Abstract: Polypyrrole-coated hollow Zn2SnO4 boxes (hollow Zn2SnO4@PPY nanocomposites) had been prepared by a microemulsion polymerization. The structural, morphological and electrochemical properties were methodically investigated by means of XRD, TGA, BJH (pore size distribution analysis), SEM, TEM, and electrochemical measurements. Results show that the hollow Zn2SnO4 boxes with the uniform and cube like structure are coated by PPY. Electrochemical measurement suggests that hollow Zn2SnO4@PPY composites exhibit better cycling properties and lower initial irreversible capacities as anode materials for lithium-ion batteries. At a current density of 60mA/g in the voltage about 0.01–3.0V, the first discharge–charge capacities of hollow Zn2SnO4@PPY composites are 1105.2mAh/g and 556mAh/g. After 50 cycles, a specific charge capacity of 478.4mAh/g remained and the coulombic efficiency reaches 98.2%, revealing better capacity retention compared with hollow Zn2SnO4 boxes. [Copyright &y& Elsevier]

Abstract: Hollow Zn2SnO4@N–C composites were synthesized after the calcined process of precursor. The N-doped carbon coating layers, as a physical buffering matrix to reinforce the hollow structure, prevent interparticle agglomeration and improve the electronic conductivity of the electrodes. Compared with our previous studies, Zn2SnO4@N–C composites show an enhanced electrochemical performance (616mAhg−1 after 45 cycles) and high rate capability. With rational and delicate design, this kind of composites may be the potential anode materials for lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: The GNS/Li2SnO3/PPY ternary composites were synthesized by a deoxidation technique. The soft polymer matrix and flexible graphene provide a dual buffering structure for Li2SnO3 which synergistic leads to improved stability, enhanced electric conductivity and better electrochemical performance. The GNS/Li2SnO3/PPY composites tested as anode materials for lithium ion batteries exhibit a high reversible capacity of 699.4mAh/g over 30 cycles, which is much better than that of pure Li2SnO3, PPY/Li2SnO3 and GNS/Li2SnO3 composites. [Copyright &y& Elsevier]

Abstract: The carbon-doped Li2SnO3/graphene composites for lithium-ion batteries were synthesized by the hydrothermal route. The structure, morphology and electrochemical properties of the composites were detected by means of XRD, SEM, TEM, Raman, TGA and electrochemical measurements. The Li2SnO3 nanoparticles are surrounded by graphene sheets (GNS) and amorphous carbon layers. The carbon-doped Li2SnO3/graphene materials exhibit good electrochemical performance with high capacity and good cycling stability (736.3mAh/g after 50 cycles at 60mA/g).The presence of graphene sheets and carbon layer can alleviate the effects of volume changes, keep the structure stable and increase the conductivity. Conclusively, The C/Li2SnO3/GNS composites exhibit better electrochemical properties than GNS/Li2SnO3 and Li2SnO3. [Copyright &y& Elsevier]