Using a simple hydrothermal procedure, cobalt oxide (Co(3)O(4)) nanowires were in situ synthesized on three-dimensional (3D) graphene foam grown by chemical vapor deposition. The structure and morphology of the resulting 3D graphene/Co(3)O(4) composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The 3D graphene/Co(3)O(4) composite was used as the monolithic free-standing electrode for supercapacitor application and for enzymeless electrochemical detection of glucose. We demonstrate that it is capable of delivering high specific capacitance of ∼1100 F g(-1) at a current density of 10 A g(-1) with excellent cycling stability, and it can detect glucose with a ultrahigh sensitivity of 3.39 mA mM(-1) cm(-2) and a remarkable lower detection limit of <25 nM (S/N = 8.5).

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A three-dimensional interconnected graphene monolith was used as an electrode support for pulsed electrochemical deposition of platinum (Pt) nanoparticles. Pt nanoparticles with well-defined morphology and small size can be obtained by controlling electrodeposition potential and time. Electrochemical characterization was carried out to examine the electrocatalytic activity of this monolithic electrode towards methanol oxidation in acidic media. The results show that the carbon material surface and structure have a strong influence on the Pt particle size and morphology. Compared with the three-dimensional scaffold of carbon fibers, the three-dimensional graphene when used as a free-standing electrode support resulted in much improved catalytic activity for methanol oxidation in fuel cells due to its three-dimensionally interconnected seamless porous structure, high surface area and high conductivity.

Three-dimensional (3D) graphene-carbon nanotube (CNT) hybrids are synthesized by two-step chemical vapor deposition (CVD) under atmospheric pressure. As revealed by scanning electron microscopy (SEM), the hybrid is a monolithic graphene foam with conformal coverage of a dense CNT mesh. We further demonstrate that the obtained graphene-CNT hybrid foams can be used as novel 3D electrochemical electrodes for sensing applications. Specifically, the 3D graphene-CNT electrodes exhibit a high sensitivity ($470.7 mA M À1 cm À2 ) and low detection limit ($20 nM with S/N z 9.2) for dopamine detection. Modified with horseradish peroxidase and Nafion, the 3D hybrid electrodes are also used to detect H 2 O 2 with a high sensitivity (137.9 mA M À1 cm À2 ), low detection limit ($1 mM with S/N z 17.4), and wide linear detection range (10 mM-1 mM).

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As a typical member of transition-metal dichalcogenides (TMDs), VS2 has been evaluated as the aluminum-ion battery cathode for the first time. To further improve their stability and conductivity, the as-prepared VS2 nanosheets are modified with graphene (denoted as G-VS2). And the G-VS2 electrode delivers a high initial discharge capacity of 186 mA h g-1 at 100 mA g-1 with almost 100% coulombic efficiency after 50 cycles. Furthermore, an explicit intercalation mechanism of Al into G-VS2 has been investigated by in/ex situ XRD, ex situ Raman and TEM spectroscopy. And the G-VS2 composite proves to be an impressive cathode material for aluminum-ion batteries (AIBs). This work might put forward the application of TMDs in AIBs.

Ionometallurgy is a new development aiming at the sustainable low‐temperature conversion of naturally occurring metal ores and minerals to their metals or valuable chemicals in ionic liquids (ILs) or deep eutectic solvents. The IL betainium bis((trifluoromethyl)sulfonyl)imide, [Hbet][NTf2], is especially suited for this process due to its redox‐stability and specific‐functionalization. The potentiostatic electrodeposition of zinc and lead starting directly from ZnO and PbO, which dissolve in [Hbet][NTf2] in high concentrations is reported. The initial reduction potentials of zinc(II) and lead(II) are about −1.5 and −1.0 V, respectively. The ionic conductivity of the solution of ZnO in [Hbet][NTf2] is measured and the effect of various temperatures and potentials on the morphology of the deposited material is explored. The IL proves to be stable under the chosen conditions. From IL‐solutions, where ZnO, PbO, and MgO have been dissolved, metallic Zn and Pb are deposited under potentiostatic control either consecutively by step‐electrodeposition or together in a co‐electrodeposition. Using the method, Zn is also deposited on 3D copper foam and assembles into high‐voltage zinc‐graphite battery. It exhibits a working‐voltage up to 2.7 V, an output midpoint discharge‐voltage of up to 2.16 V, up to 98.6% capacity‐retention after 150 cycles, and good rate performance.

The shuttle effect of lithium polysulfides (LiPS) and potential safety hazard caused by the burning of flammable organic electrolytes, sulfur cathode, and lithium anode seriously limit the practical application of lithium–sulfur (Li–S) batteries. Here, a flame‐retardant polyphosphazene (PPZ) covalently modified holey graphene/carbonized cellulose paper is reported as a multifunctional interlayer in Li–S batteries. During the discharge/charge process, once the LiPS are generated, the as‐obtained flame‐retardant interlayer traps them immediately through the nucleophilic substitution reaction between PPZ and LiPS, effectively inhibiting the shuttling effect of LiPS to enhance the cycle stability of Li–S batteries. Meanwhile, this strong chemical interaction increases the diffusion coefficient for lithium ions, accelerating the lithiation reaction with complete inversion. Moreover, the as‐obtained interlayer can be used as a fresh 3D current collector to establish a flame‐retardant “vice‐electrode,” which can trap dissolved sulfur and absorb a large amount of electrolyte, prominently bringing down the flammability of the sulfur cathode and electrolyte to improve the safety of Li–S batteries. This work provides a viable strategy for using PPZ‐based materials as strong chemical scavengers for LiPS and a flame‐retardant interlayer toward next‐generation Li–S batteries with enhanced safety and electrochemical performance.