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Functional surfaces that enable both hot water repellency and effective condensation have attracted great interest in both academic research and practical applications. Two kinds of 1-alkyl-3-methylimidazolium hexafluorophosphate ionic liquids (ILs) with different chain lengths ([C n mIm][PF 6 ], n = 4 ([BmIm][PF 6 ]), n = 8 ([OmIm][PF 6 ])) are respectively infused into the porous surface constructed by nanocone arrays of (Ni,Co)-(CO 3 ) 0.5 (OH) 0.11 H 2 O (NiCo-NCA), aiming to produce slippery surfaces (SSs) with stable non-wetting performance. Before the ILs infusion, the NiCo-NCA surface is functionalized by low surface energy material for conferring superhydrophobicity. The superhydrophobicity of the modified NiCo-NCA becomes ineffective after the heat treatment up to about 240 °C due to the formation of cracks on the surface. However, the slippery surfaces can be maintained in the ILs-infused samples followed by the same heat treatment due to the self-healing ability and thermal stability of the infused fluids. Moreover, hot water droplets are repellent on the ILs-infused SSs while pinned on the superhydrophobic surface. The nucleation process of condensing water droplets is easier on the ILs-infused SSs than that on the superhydrophobic surface. The sliding speed of the condensed water and the hot water droplets on the [OmIm][PF 6 ]-infused SS are slower than those on the [BmIm][PF 6 ]-infused SS due to the higher viscosity of [OmIm][PF 6 ]. As well, the ILs-infused SSs can endure physical damage and impacting droplet. The ILs-infused SSs shows promise potential applications in hot liquid self-cleaning and high efficiency droplet manipulation. [ABSTRACT FROM AUTHOR]

Adsorption is often time consuming due to slow diffusion kinetic. Sizing he adsorbent down might help to accelerate adsorption. For CoFe spinel oxide, a magnetically separable adsorbent, the preparation of nanosheets faces many challenges including phase separation, grain growth and difficulty in preparing two-dimensional materials. In this work, we prepared porous CoFe oxide nanosheet with chemical formula of Co 2.698 Fe 0.302 O 4 through topochemical transformation of a CoFe precursor, which has a layered double hydroxide (LDH) analogue structure and a large interlayer spacing. The LDH precursor was synthesized from a cheap deep eutectic solvent (DES) system. The calcined Co 2.698 Fe 0.302 O 4 has small grain size (10–20 nm), nanosheet morphology, and porous structure, which contribute to a large specific surface area of 79.5 m 2 g −1 . The Co 2.698 Fe 0.302 O 4 nanosheets show fast removal ability and good adsorption capacity for both organic waste (305 mg g −1 in 5 min for Congo red) and toxic heavy metal ion (5.27 mg g −1 in 30 min for Cr (VI)). Furthermore, the Co 2.698 Fe 0.302 O 4 can be separated magnetically. Considering the precursor can be prepared through a fast, simple, surfactant-free and high-yield synthetic strategy, this work should have practical significance in fabricating adsorbents. [ABSTRACT FROM AUTHOR]

Abstract: A NiO–graphene hybrid film with 3D hierarchically porous structure has been rationally designed and constructed through a series of controlled fabrication processes. Multilayered porous graphene sheet network with the pore size of several micrometers is created via a so-called “on-water spreading” method, which is facile, economical, efficient and scalable. Then, the cross-like NiO nanoflakes film is uniformly grown onto the porous graphene sheet framework by a chemical bath deposition. The NiO–graphene hybrid film exhibits specific capacitance of 540 F g−1 at 2 A g−1 with 80% capacitance retention after 2000 cycles in 2 M KOH aqueous solution, which is much higher than that achieved from the bare NiO nanoflakes film (370 F g−1, with 66% capacitance retention). Moreover, chronoamperometry and electrochemical impedance spectroscopy measurements reveal that the NiO–graphene hybrid demonstrates enhanced reaction kinetics with about only 50% of respond time for NiO/NiOOH reaction and 79% of charge-transfer resistance compared with those of the bare NiO film. The proposed strategy could offer an effective way to fabricate graphene-based electrode materials for applications in various energy-storage devices. [Copyright &y& Elsevier]

Abstract: Porous tin-based films are electrodeposited on copper foils from a choline chloride/ethylene glycol based electrolyte containing SnCl2·2H2O without any complexing agent or additive. Increasing the deposition time and voltage produces thicker films. The initially deposited Sn grains are relatively uniform with an average size of 200–300 nm and a kind of self-assembly distribution constructing an open and bicontinuous porous network. The architecture of these films possesses a double-layer structure, i.e. SnO2 (superficial layer)/Sn–Cu alloy (bottom layer), which is revealed by X-ray diffractometer and X-ray photoelectron spectroscopy. The electrochemical performance of the porous tin-based films as anode for lithium-ion batteries is measured. Although the capacity fades gradually with repeated cycling, a reversible capacity of 300-350 mAh g−1 is maintained for more than 50 cycles, which suggests that the in situ formed Sn--Cu alloy could provide an interlocking interface between active materials and current collector. Therefore, the tin''s shedding from the current collector can be restrained. Moreover, the inactive materials, such as the oxide in the superficial layer and the Cu in the bottom layer, could also act as buffers to relieve the induced volume expansion of Sn during the repeated lithiathion/delithiation process, thus giving the good cycle performances. [Copyright &y& Elsevier]

To meet the requirements for high-rate battery with desirable performance, a self-supported Ni 2 P@Ni sponge electrode is synthesized via simple steps, in which the Ni sponge substrate is synthesized by a one-pot hydrothermal method and the Ni 2 P nanosheets grown on the novel substrate are converted from Ni(OH) 2 via a phosphorization reaction. This hybrid composite combines the 3D porous structure of Ni sponge and high capacity of Ni 2 P nanosheets, which exhibits lightweight, flexible and highly-conductive properties, resulting in an excellent specific capacity of 430.3 mAh g −1 at a current density of 1 A g −1 and remaining as high as 77.0% capacity even at 40 A g −1 . More importantly, the Ni 2 P@Ni sponge//C cell exhibits the maximum energy density of 182.1 W h kg −1 at a power density of 205 W kg −1 along with superior capacity retention of 85.2% after 3000 cycles. It is suggested that the Ni 2 P nanosheet@ Ni sponge composite is a promising electrode material for high-rate batteries. [ABSTRACT FROM AUTHOR]

The construction of advanced cathode materials is indispensable and vital for developing high-performance lithium–sulfur batteries. Herein, we develop a facile in-situ route to synthesize three-dimensional reduced graphene oxide supported Li 2 S/carbon composite (3D-rGO-Li 2 S/C). The Li 2 S/C nanoparticles are intimately anchored on the surface of 3D-rGO forming an integrated 3D porous composite. Due to the improved conductivity and reduced polysulfide dissolution, the 3D-rGO-Li 2 S/C cathode exhibits enhanced electrochemical performances with a high initial capacity of 819 mAh g −1 at 0.1C, as well as good cycling stability with a capacity retention of 415 mAh g −1 after 100 cycles at 1C. The integrated 3D conductive network is responsible for the enhancement of the electrochemical properties by providing fast ion/electron transfer and high mechanical stability. [ABSTRACT FROM AUTHOR]

A novel of Si/porous reduced graphene oxide (rGO) composite is fabricated by steam etching of Si/rGO aerogel. The rGO sheets with nano-holes build a unique three-dimensional porous network and can encapsulate the Si nanoparticles. The porous structure of Si/rGO composite can reduce the transfer distance of Li ions and restrain the aggregation and destruction of Si particles. The in-situ transmission electron microscopy (TEM) observation demonstrates that the porous rGO sheets help the entire electrode to maintain highly conductive and facilitate the lithiation of Si nanoparticles. The composite electrode presents high specific capacity and good cycling stability (1004 mAh g −1 at 50 mA g −1 up to 100 cycles). [ABSTRACT FROM AUTHOR]

Abstract: Vertically aligned hierarchical WO3 nano-architectures on transparent conducting substrate (3×2.5cm2 in size and sheet resistance R s=10Ω) are produced via a template-free solvothermal method. The nanostructured array films with thicknesses of about 1.1μm show remarkable enhancement of the electrochromic properties in visible spectrum and infrared region. In particular, a significant optical modulation (66.5% and 66.0% at 633nm, 73.8% and 53.9% at 2000nm, 57.7% and 51.7% at 8μm), fast switching speed (4.6s/3.6s and 2.0s/3.4s), high coloration efficiency (126 and 120cm2 C−1 at 633nm) and excellent cycling stability (maintained 77.5% and 81.7% of the initial optical modulation after 4500-cycles) are achieved for the nanotree and nanowire arrays, respectively. The improved electrochromic properties are mainly attributed to the vertically aligned structure and the porous space among the nanotrees or nanowires, which make the diffusion of H+ in these arrays easier and also supply larger surface area for charge-transfer reactions. [Copyright &y& Elsevier]

Macroporous Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials with high crystallinity and hexagonal ordering are synthesized by aerogel template followed by solid state reaction. High discharge capacities of 244.0 mA h g−1 and 153.9 mA h g−1 are obtained for the Li-rich layered oxide synthesized at 800 °C at current densities of 200 mA g−1 and 2000 mA g−1 between 2.0 V and 4.8 V. Increasing the synthesis temperature to 900 °C, the macroporous Li1.2Mn0.54Ni0.13Co0.13O2 delivers a high discharge capacity of 220.2 mA h g−1 at a current density of 200 mA g−1 with a capacity retention of 89.1% after 50 cycles, 129.8 mA h g−1 at a current density of 2000 mA g−1 and almost no capacity fading after 120 cycles. The diffusion coefficients of Li+ in the Li-rich layered oxide determined by galvanostatic intermittent titration technique are in the range of 5.0 × 10−18−8.0 × 10−14 cm2 s−1. Electrochemical impedance spectroscopy indicates that the macroporous structure with good particle contact of the layered oxide can improve its rate capability and cyclic stability. [ABSTRACT FROM AUTHOR]

Abstract: TiO2@WO3 core/shell nanorod arrays are prepared by the combination of hydrothermal and electrodeposition method. The array films show remarkable enhancement of the electrochromic properties. In particular, a significant optical modulation (57.2% at 750nm, 70.3% at 1800nm and 38.4% at 10μm), fast switching speed (2.4s and 1.6s), high coloration efficiency (67.5cm2 C−1 at 750nm) and excellent cycling performance (65.1% after 10,000 cycles) are achieved for the core/shell nanorod arrays. The improved electrochromic properties are mainly attributed to the core/shell structure and the porous space among the nanorod array, which makes the ion diffusion become easier and it also gives larger surface area for charge-transfer reactions. The data present great promise for the TiO2@WO3 core/shell nanorod arrays as practical electrochromic materials. [Copyright &y& Elsevier]

Abstract: Porous Fe3O4/C core/shell nanorods have been prepared by a facile hydrothermal method using porous Fe2O3 nanorods as the precursor and glucose as the carbon source. The Fe3O4/C nanorods possess a uniform size with 50–80nm in diameter and 300–500nm in length, and are homogenously coated by amorphous carbon layer. The porous nanorods greatly increase the electrical contact, thus facilitating the Li-ion and electron transportation, and enhancing the reactivity of the electrode. Also, the carbon layer can effectively limit the volume expansion and detachment of Fe3O4, and thus increase its structure stability during cycling. In the context of lithium storage behavior, the Fe3O4/C nanorod electrode shows high capacity and good cycle stability, as well as enhanced rate performance. After 50 cycles, the reversible capacity of the porous Fe3O4/C nanorods is 762.1mAhg−1 at 0.1C and 597.2mAhg−1 at 0.5C, much higher than that of α-Fe2O3 nanorods (276.4mAhg−1) and Fe3O4 nanoparticles (307.9mAhg−1). At a high rate of 1C, the specific capacity of Fe3O4/C nanorods is still as high as 630.1mAhg−1. [Copyright &y& Elsevier]

Abstract: A hierarchically porous NiO film on nickel foam substrate is prepared by a facile ammonia-evaporation method. The self-assembled film possesses a structure consisting of NiO triangular prisms and randomly porous NiO nanoflakes. The pseudocapacitive behaviors of the porous NiO film are investigated by cyclic voltammograms and galvanostatic charge–discharge tests in 1M KOH. The hierarchically porous NiO film exhibits a high discharge capacitance and excellent rate capability with 232Fg−1, 229Fg−1, 213Fg−1 and 200Fg−1 at 2, 4, 10, and 20Ag−1, respectively. The specific capacitance of 87% is maintained from 2Ag−1 to 20Ag−1. The porous NiO film also shows rather good cycling stability and exhibits a specific capacitance of 348Fg−1 after 4000 cycles. [Copyright &y& Elsevier]

Abstract: Spherical Li3V2(PO4)3/C composites are synthesized by a soft chemistry route using hydrazine hydrate as the spheroidizing medium. The electrochemical properties of the materials are investigated by galvanostatic charge–discharge tests, cyclic voltammograms and electrochemical impedance spectrum. The porous Li3V2(PO4)3/C spheres exhibit better electrochemical performances than the solid ones. The spherical porous Li3V2(PO4)3/C electrode shows a high discharge capacity of 129.1 and 125.6mAhg−1 between 3.0 and 4.3V, and 183.8 and 160.9mAhg−1 between 3.0 and 4.8V at 0.2 and 1C, respectively. Even at a charge–discharge rate of 15C, this material can still deliver a discharge capacity of 100.5 and 121.5mAhg−1 in the potential regions of 3.0–4.3V and 3.0–4.8V, respectively. The excellent electrochemical performance can be attributed to the porous structure, which can make the lithium ion diffusion and electron transfer more easily across the Li3V2(PO4)3/electrolyte interfaces, thus resulting in enhanced electrode reaction kinetics and improved electrochemical performance. [Copyright &y& Elsevier]

Abstract: Self-organized macroporous tungsten trioxide (WO3) films are obtained by anodic oxidation of DC-sputtered tungsten (W) layers on 10mm×25mm indium tin oxide (ITO)-coated glass. Under optimized experimental conditions, uniformly macroporous WO3 films with a thickness of ca. 350nm are formed. The film shows a connected network with average pore size of 100nm and a pore wall thickness of approximately 30nm. The anodized film becomes transparent after annealing without significant change in macroporous structure. In 0.1M H2SO4, the macroporous WO3 films show enhanced electrochromic properties with a coloration efficiency of 58cm2 C−1. Large modulation of transmittance (∼50% at 632.8nm) and a switching speed of about 8s are also achieved with this macroporous film. [ABSTRACT FROM AUTHOR]