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Abstract The poor interfacial contact between electrode materials and electrolyte has become a major obstacle to the development and application of solid-state batteries. In this work, we report a facile method to realize interfacial modification with the help of in-situ ultraviolet solidified gel polymer electrolyte, which is completely compatible with commercial LiFePO 4 and cellulose membrane forming stable composite cathode and cellulose membrane-gel polymer electrolyte. Two intimate interfaces between LiFePO 4 and gel polymer electrolyte as well as composite cathode and cellulose membrane-based composite electrolyte are achieved to facilitate fast transfer of lithium ions at the interface. The assembled solid-state cell exhibits lower interfacial resistance, reduced polarization, higher rate capability, and more stable cycling performance than other routine counterparts. This work provides a new way for fabrication of novel advanced solid-state electrolytes and electrodes for applications in solid-state batteries. Highlights • A composite cathode with gel polymer electrolyte coating is prepared by UV curing. • A solid-state battery with intimate interface is obtained with in-situ method. • A solid-state lithium ion battery with high electrochemical performance is realized. [ABSTRACT FROM AUTHOR]

Abstract Public participation is an important means of achieving sustainable development goals (SDGs) in western countries, but it's just in its infancy in China. Does public participation in China help reduce air pollutant emissions and contribute to sustainable development? In order to answer this question, effects of the China Air Pollution Map Application on industrial pollution emissions, a natural experiment in which the public participates in environmental protection, are evaluated by using the difference-in-differences method. It is found that the launch of the Map restrains the industrial pollution discharge to a certain extent. However, its marginal effect fluctuates with the passage of time, indicating that it is not a stable means for maintaining sustainable development. Only when government policies, public and enterprise participation are jointly involved can air pollutant emissions be effectively controlled and SDGs be ultimately achieved. [ABSTRACT FROM AUTHOR]

Highlights • Taking balanced panel data of 60 countries for 1971–2012 as a sample. • The relationship between urbanization and GHG emissions is evaluated by the threshold model. • The role of urbanization path including small towns, big cities and urban agglomerations is evaluated. • The policy recommendations about GHG abatement during the process of urbanizationare provided. Abstract Taking the balanced panel data of 60 countries from 1971 to 2012 years as a sample, the relationship between urbanization and greenhouse gas (GHG) emissions was checked based on the threshold model. It was found that the relationship between the urbanization ratio and GHG emissions was always positive, suggesting that urbanization will inevitably lead to an increase in GHG emissions, irrespective of how high the rate of urbanization is. However, when the urbanization ratio passed 23.59% or the GHG emissions exceed 42,287 kt of CO 2 equivalent, urbanization will have more impact on GHG. Also, the urbanization paths influence the relationship between urbanization and GHG emissions. When the population in urban agglomerations of more than 1 million of total population is higher than 20.01% or the population in the largest city of urban population is above 48.27%, positive correlation between urbanization and environmental pollution will be more significant. [ABSTRACT FROM AUTHOR]

All-solid-state lithium batteries (ASSLIBs) employed inorganic solid electrolytes are attracting increasing interest for electrochemical energy storage devices due to their advantages of high safety, high energy density, wide operating temperature range and long cycle life. However, the large interfacial resistance originated from the insufficient solid-solid contact at electrolyte/electrode interface hinders the development of all-solid-state batteries. In addition, the interfacial compatibility and stability also greatly affect the electrochemical performance of batteries. This review summarizes the challenges and progress for the studies of interface problems in ASSLIBs. Based on the review, we attempt to propose alternative approaches to the issue and prospective developments of ASSLIBs. [ABSTRACT FROM AUTHOR]

It is a core task to find solutions to suppress the “shuttle effect” of polysulfides and improve high rate capability at the sulfur cathode of lithium sulfur batteries. Herein we first time propose a concept of multileveled blocking “dams” to suppress the diffusion of polysulfides. We report a facile and effective strategy to construct multidimensional conductive carbon hosts for accommodation of active sulfur. Multidimensional ternary carbon networks (MTCNs) with 0D nanospheres, 1D nanotubes and 2D nanoflakes are organically combined together to provide multileveled conductive channels to reserve active sulfur and promote stable sustained reactions. In the light of enhanced conductivity and multileveled blocking “dams” for polysulfides, the designed MTCNs/S cathode has been demonstrated with noticeable improvement in discharge capacity (1472 mAh g −1 at 0.l C) and long-term cycling stability (65% retention at 5.0 C after 500 cycles). Our research may provide a new insight in the gradient blocking of polysulfides with the help of multidimensional carbon networks. [ABSTRACT FROM AUTHOR]

Concerns surrounding climate change and environmental challenge make the coal utilization network essential not only for understanding the pattern of energy provision and transfer, but also for illustrating the interaction between anthropogenic activities and ecological systems at global level. This paper fills the research gap by dint of multi-regional input output model to outline coal embodied routes from natural boundaries to economic activities, and to identify the central hubs in the global coal supply chain, based on the most recent available statistics for 2011. As the economic value and environmental influences of different kinds of coals could be remarkably diverse, the separation of coal categories in systematic analysis could provide fundamental information regarding the displacement and teleconnection of coal utilization in the world. The estimation shows that in weight 64.99% of coal direct supply is ultimately embodied in international trade, indicating the crucial roles of trade interlinks in global coal utilization. Apart from this, the findings pertinent to sectoral structure, regional supply chain and per capita characteristics of coal embodied utilization, could be valuable to identify the global energy routes driven by international trade as well as to facilitate energy and environmental policy. [ABSTRACT FROM AUTHOR]

Coal-based power generation accounts for over two fifths of global electricity supply and is supposed to be continuing its leading role in the coming decades. However, an integrated embodied energy accounting for typical coal-fired power system seems to be in its vacancy. To help erect a benchmark for energy analysis of electricity production, this study has for the first time established a complete inventory of energy inputs in the life cycle of a typical coal-fired power plant. Distinguished from previous works, with the support of ecological input–output database, this paper gives full consideration to the energy embodied in materials, equipment and services that have been traditionally neglected. The indirect energy cost is illustrated to be a non-negligible component, sharing around one-tenth of the total. This work could be a reference example for holistic energy evaluation of power generation systems worldwide. In current context of energy conservation and emissions abatement, it is of significant importance as the retrofitting of power generation systems may initiate large amounts of indirect energy cost. Besides, by calculating the nonrenewability indicator for the typical coal-fired power system, the energy saving potentials of several renewable alternatives are enunciated in this work. It may provide essential implications for policy makers in renewable deployment. [ABSTRACT FROM AUTHOR]

In this work, we develop a facile electro-deposition method to assemble Co ultrathin shell on the Co 3 O 4 nanowires forming Co 3 O 4 @Co core/branch arrays (CBAs). Co nanoshell of 5–10 nm is homogeneously connected with each other and forms a conductive “armor” on the Co 3 O 4 nanowires. Attractive advantages including high electronic conductivity and large porosity are combined in the designed core/branch architecture. Compared with the unmodified Co 3 O 4 nanowires, the Co 3 O 4 @Co CBAs have been demonstrated with higher capacity and better cycling stability. A specific capacity of 649 mAh g −1 is obtained for the Co 3 O 4 @Co electrode at 3 A g −1 , much higher than that (431 mAh g −1 ) of the Co 3 O 4 nanowires counterpart. In addition, after 300 cycles at 0.25 A g −1 , the Co 3 O 4 @Co electrode delivers a stable capacity of 863 mAh g −1 , better than the pristine Co 3 O 4 counterpart (686 mAh g −1 ) owing to better conductive networks and more stable electrode structure. [ABSTRACT FROM AUTHOR]

Design/fabrication of solid state electrolytes with high ionic conductivity is of great importance to develop next-generation Li ion batteries. In this work, the Li 7 P 3 S 11 glass-ceramic electrolyte is successfully synthesized by dissolution- evaporation approach. The solvent effect on the electrochemical performance of Li 7 P 3 S 11 is investigated by electrochemical impedance spectroscopy and chronoamperometry tests. The Li 7 P 3 S 11 electrolyte prepared by a solution of acetonitrile has a high ionic conductivity of 9.7 × 10 −4 S cm −1 at 298 K and a low activation energy of 31.2 kJ mol −1 . Impressively, a wide and stable electrochemical window up to 5 V (vs. Li/Li + ) is demonstrated between the solid electrolyte and lithium electrode. The developed dissolution-evaporation approach shows good industrial prospect due to its advantages of energy conservation and high efficiency. [ABSTRACT FROM AUTHOR]

Energy strategies in China׳s 11th and 12thzfive-year Plan failed to reduce the total energy consumption and misled the implementation of energy saving measures, as they were focused towards the direct energy input as well as formulated based on incomplete energy consumption information. Therefore, an optimal energy abatement strategy built on comprehensive information on overall embodied energy consumption is in urgent need. Adopting the three-scale input-output analysis, this study uses Beijing as a case to depict a specific urban economy׳s overall energy consumption impacted by local direct energy use, domestic and foreign trade. The results show that energy embodied in domestic trade dominated Beijing׳s energy consumption, while local direct energy is accounting for less than 1/3 of Beijing׳s total embodied energy consumption. The quantity of energy embodied in imports far exceeds that embodied in exports, making the city a net embodied energy importer and indicating that policies considering direct energy use only will cause energy leakage problem. These findings suggest that the current measures such as displacing energy-intensive sectors to other regions lead to “local reduction but overall rise”. Moreover, analysis for five abatement scenarios (average, intensity share, absolute share, discriminatory absolute and discriminatory intensity) was carried out to figure out the optimal abatement strategy for Beijing. Due to less loss of potential output, it is found that intensity share scenario is the optimal one among all the scenarios concerned. Analysis in this study suggests that each region should break limits of self-centered perceptions and multi-scale governance for more appropriate responsibility assignment is recommended for overall energy abatement. [ABSTRACT FROM AUTHOR]

The facilitation of regional trade has boosted the fragmentation in global supply chain, integrating the production, energy and other ecological factors across the regional boundaries by virtue of vertical specialization. The consequences of this trend on urban energy consumption are firstly analyzed by constructing multiregional input–output table and decomposing the value added export in Beijing. Energy consumption per unit of GDP in Beijing is only half of that per unit of value added after adjusting the export by virtue of decomposition techniques and Beijing displays no obvious advantages in energy usage when considering the value added processes. Energy intensive parts of production are relocated outside the metropolis by the downstream and upstream participation in global areas. The results of value added export for energy consumption reveal that the vertical specialization in this metropolis slashes the amount of energy consumption in the city but raises that in the outside. The unified framework by integration of the value added export and energy consumption in this paper could be extended to other related topics. [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]

Porous hierarchical nanostructures have received wide attention in high-performance lithium ion batteries (LIBs) applications. In this work, we report a simple strategy for the fabrication of porous Co/Co 3 O 4 –C core-branch nanowire arrays. By the aid of chemical bath deposition, electro-deposition and annealing process, Co 3 O 4 –C nanoflake branch is successfully assembled on the Co core nanowires forming the aligned core-branch nanowires with diameters of about 550 nm. As anode materials for LIBs, the Co/Co 3 O 4 –C core-branch nanowire arrays exhibit high reversible capacity, improved cycle stability as well as good rate capability. A specific capacity of 608 mAh g −1 is obtained at 0.5C after 200 cycles, much higher than the unmodified Co 3 O 4 nanoflake arrays (501 mAh g −1 at 0.5C after 200 cycles). The enhanced electrochemical properties are mainly ascribed to the porous core-branch architecture with faster ion/electron transfer path. This newly developed method can be extended to prepare other advanced core-branch nanomaterials for applications in electrochemical and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Construction of high-capacity anode is highly important for the development of next-generation high-performance lithium ion batteries (LIBs). Herein we fabricate Si/Ag nanowires/reduced graphene oxide (Si/Ag NWs/rGO) integrated composite film by introducing binary conductive networks (Ag NWs and rGO) into Si active materials with the help of a facile vacuum-filtration method. Active Si nanoparticles are homogeneously encapsulated by binary Ag NWs-rGO conductive network, in which Ag NWs are interwoven among the rGO sheets. The electrochemical properties of the integrated Si/Ag NWs/rGO composite film are thoroughly characterized as anode of LIBs. Compared to the Si/rGO composite film, the integrated Si/Ag NWs/rGO composite film exhibits enhanced electrochemical performances with higher capacity, better high-rate capability and cycling stability (1269 mAh g −1 at 50 mA g −1 up to 50 cycles). The binary conductive network plays a positive role in the enhancement of performance due to its faster ion/electron transfer, and better anti-structure degradation caused by volume expansion during the cycling process. [ABSTRACT FROM AUTHOR]

Tailored metal oxide/carbon composite structures have attracted great attention due to potential synergistic effects and enhanced properties. In this work, novel CuO/C core/shell nanowire arrays are prepared by the combination of electro-deposition of CuO and atomic-layer-deposition-assisted formation of carbon nanoflakes shell. The CuO nanowires with diameters of ∼200 nm are homogenously coated by carbon nanoflakes shell. When evaluated as anode materials for lithium ion batteries (LIBs), compared to the unmodified CuO nanowire arrays, the CuO/C core/shell nanowire arrays exhibit improved electrochemical performances with higher capacity, better electrochemical reactivity and high-rate capability as well as superior cycling life (610 mAh g −1 at 0.5C after 290 cycles). The enhanced electrochemical performance is mainly attributed to the introduction of carbon flake shell in the core/shell nanowire arrays structure, which provides higher active material-electrolyte contact area, improved electrical conductivity, and better accommodation of volume change. The proposed method provides a new way for fabrication of high-performance metal oxides anodes of LIBs. [ABSTRACT FROM AUTHOR]

Tailored high-activity cathode materials are of great importance for construction of high-performance capacitors and hybrid batteries. In this work, we report a facile template-free chemical bath deposition method to fabricate porous Co 3 O 4 nanoflake microspheres consisting of self-assembled nanoflakes with thicknesses of ∼10 nm. The as-prepared Co 3 O 4 microspheres have average diameters of ∼2 μm and the secondary Co 3 O 4 nanoflakes are interconnected with each other forming a highly open net-structure with pore diameters of 20-200 nm. When evaluated as cathode materials for pseudocapacitive hybrid batteries, the Co 3 O 4 nanoflake microspheres deliver a specific capacity of 83 mAh g −1 at 1 A g −1 after 10,000 cycles, higher than the Co 3 O 4 nanowire microspheres counterpart (70 mAh g −1 ). In addition, the electrode exhibits excellent long-term cycling stability with 94.5% capacity retention after 10,000 cycles at 1 A g −1 . The enhancement of high-rate electrochemical performances is due to the unique nanoflake microspheres architecture with large surface area and open porous structure. [ABSTRACT FROM AUTHOR]

Highlights: [•] We prepared a self-supported porous Co3O4/C core/shell nanowire array. [•] Core/shell nanowire array showed high pseudo-capacitive properties. [•] Core/shell array structure was favorable for fast ion and electron transfer. [Copyright &y& Elsevier]

Abstract: A hierarchically Fe2O3@Co3O4 nanowire array is prepared by the aid of hydrothermal synthesis and sacrificial hydrolysis method. The obtained nanowire array shows hierarchical porosity and large surface area. The resulted Fe2O3@Co3O4 nanowire array is evaluated as an anode material for Li ion batteries, which exhibits high capacity and good cycle stability (1005.1 mAh g−1 after 50 cycles at a current density of 200 mA g−1) and an excellent rate performance, mainly owing to the unique hierarchical nanowire architecture and an elegant synergistic effect of two electrochemically active materials. The developed strategy can be readily generalized to construct other multifunctional hybrid nanostructures, which will be promising materials for high-performance electrochemical devices. [Copyright &y& Elsevier]

Abstract: We report self-supported porous Co/NiO core/shell nanowire arrays via the combination of hydrogen reduction and chemical bath deposition methods. The Co nanowire acts as the backbone for the growth of NiO nanoflake shell forming hierarchically porous Co/NiO core/shell nanowire arrays. As electrode materials for pseudo-capacitors, the Co/NiO core/shell nanowire arrays exhibit a specific capacitance of 956Fg−1 at 2Åg−1 and 737Fg−1 at 40Åg−1, and good cycling stability, which is mainly due to the metal nanowire based core/shell nanowire architecture which provides good conductive network as well as fast ion/electron transfer and sufficient contact between active materials and electrolyte. [Copyright &y& Elsevier]

Abstract: A unique cobalt nanomountain array supported Si film was successfully fabricated by the combination of electrodeposition and radiofrequency magnetron sputtering. The nanostructured Si film with a proper thickness shows excellent cyclic performance with a high discharge capacity of 1917.8mAhg−1 after 100 cycles at 0.1C, also presents high rate capability with revisable capacities of 1953.3mAhg−1 at 0.5C and 1166.1mAhg−1 at 3C. The improved electrochemical performance can be attributed to the strengthening adhesion of the Si film to the cobalt nanomountain arrays and the formation of an island structure within the film, which provide good mechanical support and electron conducting pathway. The well-designed nanostructured Si electrode is a promising material for application of lithium ion batteries. [Copyright &y& Elsevier]

Abstract: A three-dimensional (3D) porous nano-Ni supported Si composite film is successfully fabricated by the combination of hydrogen bubble template electrodeposition of porous nano-Ni film and radiofrequency magnetron sputtering amorphous silicon. As anode for lithium-ion batteries, the 3D porous Ni/Si composite film shows noticeable electrochemical performance with high capacity of 2444mAhg−1 at a current density of 0.84Ag−1, superior capacity retention of 83% after 100 cycles, as well as excellent rate capability with 1420 and 1273mAhg−1 at charge–discharge current densities of 4.2Ag−1 and 8.4Ag−1 after 100 cycles, respectively. The enhanced electrochemical performance is mainly attributed to the highly porous conductive architecture, which provides good mechanical support and electron conducting pathway for active silicon and alleviates the structure degradation caused by volume expansion during the cycling process. [Copyright &y& Elsevier]

Abstract: We report a silicon/graphene-sheet hybrid film prepared by combining electrophoretic deposition and radiofrequency magnetron deposition methods. The constructed hybrid film shows rough morphology with wrinkles and scrolling edges. As anode material for lithium ion batteries, the silicon/graphene-sheet hybrid film exhibits enhanced electrochemical performances with weaker polarization, higher capacity, better rate capability and cycling performance as compared to the bare silicon film. The silicon/graphene-sheet hybrid film delivers a high initial reversible capacity of 2204mAhg−1 and quite good cycling life (capacity maintenance is 87.7%) after 150cycles. The graphene-sheet in the hybrid film is responsible for the improvement of the electrochemical properties. The introduction of the graphene-sheet film not only enhances the adhesion between silicon and the current collector, but also alleviates the structure degradation caused by volume expansion and the shrinkage of silicon film during lithium-ion insertion/extraction, resulting in improved electrochemical performances. [Copyright &y& Elsevier]

Abstract: Self-supported nickel-coated NiO arrays are prepared by chemical bath deposition of NiO flake arrays followed by magnetron sputtering of nickel nanoparticles. The effect of sputtering time, namely, coverage of nickel nanoparticles, on the lithium storage performance of Ni-coated NiO array electrode is investigated. It is found that the optimum sputtering time is 60s, and such electrode delivers a reversible capacity of 455, 316 and 187mAhg−1 at a current density of 2, 4 and 7.18Ag−1, respectively, higher than the bare NiO array electrode. The deposited nickel nanoparticles keep the NiO active particles electrically connected and thus improve the electronic conductivity, and also stabilize the flake microstructure during cycling, resulting in the increase in reversible capacity and rate capability. The Ni-coated NiO array electrode, however, is still suffered from a large voltage hysteresis, indicating that the enhanced electronic conductivity is not effective on decreasing this hysteresis. [Copyright &y& Elsevier]

Abstract: It is highly desirable to induce significant red-shift in the optical absorption edges of TiO2 phases so that this class of low-cost and environmentally friendly materials can be used as effective optical absorbing materials in novel photovoltaic cells with long-term sustainability or smart photo-catalysts beyond the ultraviolet range. This work focuses on studying the mechanisms of Mn-induced red-shift by combining theoretical modeling with advanced structural and spectroscopic characterization of doped thin films, aiming to provide fundamental guidance for effective doping through enhanced understanding of doping chemistry resulting from the interplay between doping atoms and defects. It is shown that Mn atoms doped into the Ti lattice sites are associated with oxidation valency higher than +3, resulting in maximized effectiveness in modifying the band structure to achieve remarkable optical red-shifting. The presence of oxygen vacancies reduces the Mn valency and its red-shifting effect, but their detrimental effect in bringing about localized defect levels is reduced owing to their association with Mn atoms, making Mn doping highly promising in activating various visible light functionalities of TiO2. [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: Hierarchically porous Co3O4 film is prepared by a cathodic electrodeposition via liquid crystalline template. The as-prepared Co3O4 film has a net-like structure of interconnected nanoflakes with a thickness of 15–20nm. Interestingly, the Co3O4 nanoflakes possess mesoporous walls ranging from 2 to 3nm. As cathode material for supercapacitors, the hierarchically porous Co3O4 film exhibits superior supercapacitor performances with high specific capacitances (443Fg−1 at 2Ag−1 and 334Fg−1 at 40Ag−1) as well as excellent cycle life, making it suitable for high-performance supercapacitor application. The improved supercapacitor performances are due to its unique hierarchically porous morphological characteristics, which provide fast ion and electron transfer, large reaction surface area, resulting in fast reaction kinetics. [Copyright &y& Elsevier]

Abstract: TiO2 nanocrystalline powders with various Mn-doping levels were synthesized by the sol–gel process using tetrabutyl titanate and manganese nitrate as precursors. The crystal structure, morphology, doping concentration, optical absorption property, and elemental state of the obtained samples were analyzed. TEM results showed that the synthesized TiO2 powders were anatase nanoparticles about 7nm in size. EDX and XPS analyses proved the incorporation of Mn ions into the TiO2 lattice. A remarkable red shift of the absorption edge was achievable by increased Mn content, leading to gigantically narrowed energy gap to permit absorption well into the infrared spectral region. The dramatic optical absorbance of the doped TiO2 nanopowders in the visible spectral region led to strong photocatalytic activity under visible light illumination, which was observed by measuring the degradation of methylene blue. In contrast, little degradation was observed for the pure TiO2 powder. The optimum Mn/Ti ratio was observed to be 0.2at.% for photocatalytic applications. [Copyright &y& Elsevier]

Abstract: Porous ZnO nanosheets are grown directly on copper substrates by a chemical bath deposition technique followed by a heat treatment. The materials are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Their electrochemical properties as anodes of lithium ion batteries are examined by cyclic voltammetry (CV) and galvanostatic discharge–charge tests. The results show that porous ZnO nanosheets exhibit higher reversible capacities and better cyclabilities than those of commercial ZnO powders. When cycled at 0.05Ag−1, these nanosheets deliver initial discharge and charge capacities of 1120 and 750mAhg−1, and at 0.5Ag−1, they keeps stable capacities of 400mAhg−1 up to 100 cycles, in addition, they also exhibit good rate capabilities. It is believed that the porous sheet nanostructure plays an important role in the electrochemical performance. [Copyright &y& Elsevier]

Abstract: A porous net-like β-Ni(OH)2/γ-NiOOH composite film is prepared by a chemical bath deposition. The as-prepared porous composite film shows a highly porous structure built up by many interconnected nanoflakes with a thickness of about 20nm. The pseudocapacitive behavior of the porous composite film is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 1M KOH. The porous β-Ni(OH)2/γ-NiOOH composite film exhibits a noticeable pseudocapacitance with 1420Fg−1 at 2Ag−1 and 1098Fg−1 at 40Ag−1, respectively, much higher than those of the dense Ni(OH)2 film (897Fg−1 at 2Ag−1 and 401 at 40Ag−1). The porous architecture is responsible for the enhancement of the electrochemical properties, and it increases electrochemical reaction area, shortens ions diffusion paths and relaxes volume change caused by the electrochemical reactions. [Copyright &y& Elsevier]

Abstract: Highly ordered porous NiO film is prepared by self-assembled monolayer polystyrene sphere template-assisted electrodeposition. The as-prepared NiO film shows an ordered hexagonal close-packed bowel-like array that is made up of macrobowls with about 500nm in diameter. The electrochromic properties of NiO film are investigated in an aqueous alkaline electrolyte (0.1M KOH) by means of transmittance, cyclic voltammetry and chronoamperometry measurements. The ordered porous NiO film prepared with PS sphere template exhibits a noticeable electrochromism with reversible color changes from transparent to dark brown, and presents quite good transmittance modulation with a variation of transmittance up to 76% at 550nm. The ordered porous NiO film also shows high coloration efficiency (41cm2 C−1), fast switching speed (3s and 6s) and good cycling performance, compared with the dense NiO film prepared without PS sphere template. The improvements of electrochromic performances are attributed to the highly porous morphology, which shortens the ion diffusion paths and provides bigger surface area. [Copyright &y& Elsevier]

Abstract: Mesoporous nanowall cobalt oxide (Co3O4) thin films were prepared by a liquid crystal templated electrodeposition method. The as-prepared Co3O4 thin films exhibited a highly porous nanowall structure composed of many interconnected nanoflakes with a thickness of 10–25nm. The nanoflakes showed continuous mesopores ranging from 4 to 15nm and formed a net-like structure leaving pores of 20–250nm. The electrochromic performances of the Co3O4 thin films were characterized by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The Co3O4 thin film annealed at lower temperature exhibited better electrochromic performance. The film annealed at 200°C exhibited a transmittance modulation of 40% at 633nm with a coloration efficiency of 31cm2 C−1, and fast response times with 2.5s for coloration and 2s for bleaching. The high porosity and big surface area were responsible for the enhanced electrochromic properties. [ABSTRACT FROM AUTHOR]

Abstract: Hierarchically ordered porous nickel oxide array film was prepared by electrodeposition through monolayer polystyrene spheres template. The as-prepared film had a highly porous structure of interconnected macrobowls array possessing nanopores. As anode material for lithium ion batteries, the porous array NiO film exhibited weaker polarization, higher coulombic efficiency and better cycling performance in comparison with the dense NiO film. After 50cycles, the discharge capacity of porous array NiO film was 518mAhg−1 at 1C rate, higher than that of the dense NiO film (287mAhg−1). The enhancement of the electrochemical properties was due to the unique hierarchical porous architecture, which provided fast ion/electron transfer and alleviated the structure degradation during the cycling process. [Copyright &y& Elsevier]

Abstract: Hierarchical porous cobalt oxide (Co3O4) array films are successfully prepared by electrodeposition through polystyrene sphere monolayer template. The as-prepared Co3O4 array films exhibit three typical porous structures from non-close-packed bowl array to close-packed bowl array and hierarchical two layer array structures. These Co3O4 array films have a hierarchical porous structure, in which the skeleton is composed of ordered arrays possessing nanoporous walls. A possible growth mechanism of porous Co3O4 array films is proposed. As anodes for Li ion batteries, the as-prepared Co3O4 array films exhibit quite good cycle life and high capacity. The first discharge capacity for the three Co3O4 array films is 1511, 1475, 1463mAhg−1, respectively, and their initial coulombic efficiencies are as high as 72%. The specific capacity after 50 cycles for the three electrodes is 712, 665 and 640mAhg−1 at 1C rate, corresponding to 80%, 75%, 72% of the theoretical value (890mAhg−1), respectively. [Copyright &y& Elsevier]

Abstract: We report a self-supported Co3O4 nanowire array film prepared by a facile thermal oxidative decomposition method and its fast electrochomic properties. The electrochromic performances of Co3O4 nanowire array film are investigated in 0.1M KOH by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The effective area of the Co3O4 nanowire array film is 2×2cm–2. The Co3O4 nanowire array film exhibits a transmittance modulation of 32% in the visible region and fast response times with 1.8s for coloration and 1.4s for bleaching. The electrochemical stability of the Co3O4 nanowire array film is characterized by chronoamperometry with potentiostatic cycling. After 4500 cycles, the peak currents of the film maintain 88% of the highest values. [Copyright &y& Elsevier]

Abstract: A hierarchically porous cobalt oxide (Co3O4) array film, in which the skeleton is composed of ordered non-close-packed bowl array possessing nanoporous walls, is successfully prepared by electrodeposition through self-assembled monolayer polystyrene sphere template. As an anodic coloring material for electrochromic application, the hierarchically porous Co3O4 array film exhibits enhanced electrochromic properties with higher optical modulation, faster switching speed and better cycling performance, compared to dense Co3O4 film. The porous Co3O4 array film presents a quite good transmittance modulation with 42% in the visible range and also shows good reaction kinetics with fast response time of about 2s, much higher than those of the dense film (25% and 4.5s). The better electrochromic performances of the porous film are attributed to its highly porous morphology, which shortens the ion diffusion paths and provides bigger surface area. [Copyright &y& Elsevier]

Abstract: We report a nanoporous NiO/poly(3,4-ethylenedioxythiophene) (PEDOT) composite film using a highly porous NiO film as a template by the combination of chemical bath deposition and electro-polymerization methods. The as-prepared NiO/PEDOT composite film has an interconnecting reticular morphology with nanometer sized pores ranging from 20–150nm. The NiO/PEDOT composite film exhibits multicolor electrochromism with reversible color changes from purple to light blue brown and presents a transmittance variation of 31% at 600nm. Fast switching speed is achieved in this composite film, and the response time for oxidation and reduction is 500 and 600ms, respectively. [Copyright &y& Elsevier]

Abstract: Copper-doped titania with variable Cu/Ti ratios have been prepared via a simple aqueous-phase method at 85°C. The obtained products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV–vis absorption spectra analysis. The photocatalytic properties of the products were tested by photocatalytic degradation of aqueous brilliant red X-3B solution. The results showed that the sample with 2% copper doping has the best photocatalytic activity, which is 3 times that of undoped rutile titania. The effect of the doped copper on the structure and property of TiO2 has also been discussed. [Copyright &y& Elsevier]

Abstract: A highly porous cobalt oxide thin film was prepared on ITO glass by a facile chemical bath deposition (CBD) method. The as-prepared cobalt oxide film has an intercrossing net-like morphology. The electrochromic performance of cobalt oxide film was investigated in 0.1MKOH by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The cobalt oxide thin film exhibits a noticeable electrochromism with reversible color changes from pale yellow to dark grey and presents a transmittance variation with 36% in the visible range. The porous cobalt oxide thin film also shows good reaction kinetics with fast switching speed, and the coloration and bleaching time are 2.5 and 2s, respectively. [Copyright &y& Elsevier]

Abstract: A chemical co-precipitation method was attempted to synthesize nickel hydroxide/carbon composite material for high-power Ni/MH batteries. The XRD analysis showed that there were a large amount of defects among the crystal lattice of the Ni(OH)2/C composite, and the SEM investigation revealed that the as-synthesized spherical particles were composed of hundreds of nanometer crystals with a unique three-dimensional petal shape. Compared with pure Ni(OH)2, the Ni(OH)2/C composite showed improved electrochemical properties such as superior cycling stability, higher discharge capacity and higher mean voltage of discharge under high-rate discharge conditions, the discharge capacity and the mean discharge voltage of the Ni(OH)2/C composite were about 281mAhg−1 and 0.303V (vs. Hg/HgO) at 1C-rate, 273mAhg−1 and 0.296V at 5C-rate, 250mAhg−1 and 0.292V at 10C-rate, respectively. The cyclic voltammetry (CV) tests showed that the Ni(OH)2/C composite exhibited good electrochemical reversibility and the formation of γ-NiOOH during the charge–discharge processes was prevented. The existence of carbon in the Ni(OH)2/C composite contributed great effect on the improvement of high-rate discharge performance. [Copyright &y& Elsevier]

Abstract: TiO2 particles, rods, flowers and sheets were prepared by hydrothermal method via adjusting the temperature, the pressure and the concentration of TiCl4. The as-prepared TiO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra and N2 adsorption–desorption measurements. It was found that pressure is the most important factor influencing the morphology of TiO2. The photocatalytic activity of the products was evaluated by the photodegradation of aqueous brilliant red X-3B solution under UV light. Among the as-prepared nanostructures, the flower-like TiO2 exhibited the highest photocatalytic activity. [Copyright &y& Elsevier]

Abstract: NiO thin films on ITO substrate were prepared by chemical bath deposition (CBD) and sol–gel method, respectively. The microstructure and morphology of the NiO films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Both the films have polycrystalline cubic NiO, but have distinct morphology. The CBD NiO thin film with a highly porous structure exhibited a noticeable electrochromic performance. The variation of transmittance was high up to 82% at 550nm and the coloration efficiency (CE) was calculated to be 42cm2 C−1. The sol–gel NiO thin film with a smoothly compact structure presented 35% and 28cm2 C−1 at 550nm, respectively. The electrochemical properties of both the NiO thin films were investigated in 1M KOH electrolyte by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The CV and EIS measurements revealed that the CBD NiO thin film had better electrochemical reversibility, higher reactivity and reaction kinetics due to its highly porous structure. [Copyright &y& Elsevier]

Abstract: Highly porous nickel oxide thin films were prepared on ITO glass by a simple chemical bath deposition (CBD) method in combination with a following heat-treatment process. XRD analysis revealed that the as-deposited precursor film contained β-Ni(OH)2 and γ-NiOOH, and they changed to cubic polycrystalline NiO after annealing. The FTIR results showed presence of free hydroxyl ion and water in the NiO thin films. The electrochromic properties of NiO thin films were investigated in an aqueous alkaline electrolyte (1M KOH) by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The NiO thin film annealed at 300°C exhibited a noticeable electrochromism and good memory effect. The coloration efficiency was calculated to be 42cm2 C−1 at 550nm, with a variation of transmittance up to 82%. The porous NiO thin films also showed good reaction kinetics with fast switching speed, and the coloration and bleaching time were 8 and 10s, respectively. [Copyright &y& Elsevier]

Abstract: TiO2 nanoarrays were successfully synthesized by an ultrasonic method in TiCl4/HCl solution. The products were investigated by XRD, SEM, TEM and SAED techniques. The results indicated that the products were pure single crystal rutile TiO2 nanoarrays. The size of the arrays ranged from 20 to 300 nm with each of them consisting of small nanorods of about 8 nm in diameter and 200 nm in length. The growth mechanism of the TiO2 nanostructure was also discussed. The photocatalytic activity of the products was investigated by photodegradation of aqueous brilliant red X-3B solution. It was found that the arrays exhibited better photocatalytic activity both than TiO2 nanorods and Degussa P25. [Copyright &y& Elsevier]

Abstract: The contamination of polycyclic aromatic hydrocarbons (PAHs) has become one of the major problems in the Yellow River of China. As the Yellow River is the most turbid large river in the world, it remains unknown to which extent the high suspended sediment content in the river may affect the fate and effect of PAHs. Here we report the effect of sediment on biodegradation of chrysene, benzo(a)pyrene and benzo(g,h,i)perylene with phenanthrene as a co-metabolism substrate in natural waters from the Yellow River. Biodegradation kinetics of the PAHs in the river water with various levels of sediment contents were studied in the laboratory by fitting with a biodegradation kinetics model for organic compounds not supporting growth. The results indicated that the biodegradation rates of PAHs increased with the sediment content in the water. When the sediment contents were 0, 4 and 10g/l, the biodegradation rate constants of chrysene with the initial concentration of 3.80μg/l were 0.053, 0.084 and 0.111d−1, respectively. Further studies suggested the enhanced biodegradation rate in the presence of sediment was caused by the following mechanisms: (1) the population of PAH-degrading bacteria in the water system was found to increase with the sediment content; the bacteria population on sediment phase was far greater than that on water phase during the cultivation process; (2) the sorption of PAHs on the sediment phase was well described by the dual adsorption–partition model. Although the sorption capacity of PAH per unit weight of sediment decreased with the increase of the sediment content, the amount of sorbed PAH increased with the sediment content; and, (3) the desorption of PAHs from the solid phase led to a higher concentration near the water–sediment interface. Since the bacteria were also attached to the interface, this resulted in an increased contact chance between the bacteria and PAHs. [Copyright &y& Elsevier]

In this research, the mechanism regarding the effects of suspended solids on nitrification in freshwater systems with high solid contents was examined. Experimental studies were conducted for natural water of the Yellow River under laboratory conditions. Nitrification kinetics was investigated in water systems with various levels of suspended-solid contents. The associated mechanisms were analyzed through investigation of the adsorption–desorption of ammonium nitrogen, the process of bacteria growth, and the feature of nitrification kinetics. The results indicated that the presence of suspended solids could accelerate the nitrification process. The nitrification rate would increase non-linearly with the increase of suspended-solid content. When the initial concentration of ammonia nitrogen was 12.70mg/l in the water system, the ratios of half-time duration for nitrification would be 1.88:1.23:1 under suspended-solid contents of 0, 1.84 and 5.00g/l, respectively. When the initial concentration of ammonia nitrogen was around 1.0mg/l in the water system, the nitrification rates in systems with suspended-solid contents of 1.81 and 3.42g/l would then be approximately 9 and 12 times that without suspended solids, respectively. The populations of nitrifying bacteria would rise with increasing suspended-solid content. The existence of suspended solids would increase the contact chances between bacteria and nitrogen, resulting in accelerated nitrification processes; this was manifested by the increased K4 (μmax/KS) along with the raised suspended-solid contents while fitting nitrification kinetics with the growth-based logistic model. Since the amount of ammonium nitrogen adsorbed on suspended-solid surface was non-linearly proportional to the suspended-solid content, the nitrification rate was also non-linearly proportional to the suspended-solid content. [Copyright &y& Elsevier]

The paper presents an analytical method to solve the elastodynamic problem of a finite-length orthotropic hollow cylinder subjected to a torsion impact often occurring in engineering fields. The elastodynamic solution is composed of a quasi-static solution of homogeneous equation satisfied with the non-homogeneous boundary condition and a dynamic solution of non-homogeneous equation satisfied with homogeneous boundary condition. The quasi-static solution can be obtained by directly solving the quasi-static equation satisfied with the non-homogeneous boundary condition. The solution of a non-homogeneous dynamic equation is obtained by means of a finite Hankel transform to a radial variable r, Laplace transform to a time variable t and finite Fourier transform to an axial variable z. Thus, the elastodynamic solution of the finite length of an orthotropic hollow cylinder subjected to a torsion impact is obtained. On the other hand, a dynamic finite element for the same problem is also carried out by applying the ANSYS finite-element analysis system. Comparing the theoretical solution with finite-element solution, it can be found that two kinds of results obtained by making use of two different solving methods are suitably approached. Therefore, it is further concluded that the methods and computing processes of the theoretical solution are effective and accurate. [Copyright &y& Elsevier]

This paper comprehensively examines the existence and significance of a contemporaneous/intertemporal risk-return trade-off for crude oil futures using high-frequency transaction data. The results reveal that the contemporaneous relation between risk (volatility risk, downside risk or jump risk) and return in the crude oil futures market is negative and statistically significant and that the contemporaneous negative relation between downside risk and return is stronger than the two others. However, the intertemporal volatility/jump risk-return relationship is insignificant, and there is weak negative correlation between downside risk and expected return in the crude oil futures market. These findings can be explained by the asymmetric effect of risk on returns. The findings are robust across different samples and different measures of volatility, downside and jump risks. Thus, there is no risk-return trade-off in the crude oil futures market. [ABSTRACT FROM AUTHOR]

Tailored design/construction of high-quality sulfur/carbon composite cathode is critical for development of advanced lithium-sulfur batteries. We report a powerful strategy for integrated fabrication of sulfur impregnated into three-dimensional (3D) multileveled carbon nanoflake-nanosphere networks (CNNNs) by means of sacrificial ZnO template plus glucose carbonization. The multileveled CNNNs are not only utilized as large-area host/backbone for sulfur forming an integrated S/CNNNs composite electrode, but also serve as multiple carbon blocking barriers (nanoflake infrastructure andnanosphere superstructure) to physically confine polysulfides at the cathode. The designedself-supported S/CNNNs composite cathodes exhibit superior electrochemical performances with high capacities (1395 mAh g −1 at 0.1C, and 769 mAh g −1 at 5.0C after 200 cycles) and noticeable cycling performance (81.6% retention after 200 cycles). Our results build a new bridge between sulfur and carbon networks with multiple blocking effects for polysulfides, and provide references for construction of other high-performance sulfur cathodes. [ABSTRACT FROM AUTHOR]

Rational construction of advanced FeS 2 cathode is one of research hotspots, and of great importance for developing high-performance lithium ion batteries (LIBs). Herein we report a facile hydrolysis-sulfurization method for fabrication of FeS 2 /C nanotubes arrays with the help of sacrificial Co 2 (OH) 2 CO 3 nanowires template and glucose carbonization. Self-supported FeS 2 /C nanotubes consist of interconnected nanoburrs of 5–20 nm, and show hierarchical porous structure. The FeS 2 /C nanotubes arrays are demonstrated with enhanced cycling life and noticeable high-rate capability with capacities ranging from 735 mAh g −1 at 0.25 C to 482 mAh g −1 at 1.5 C, superior to those FeS 2 counterparts in the literature. The composite nanotubes arrays architecture plays positive roles in the electrochemical enhancement due to combined advantages of large electrode-electrolyte contact area, good strain accommodation, improved electrical conductivity, and enhanced structural stability. [ABSTRACT FROM AUTHOR]

Scrupulous design and fabrication of advanced anode materials are of great importance for developing high-performance lithium ion batteries. Herein, we report a facile strategy for construction of free-standing and free-binder 3D porous carbon coated MoS 2 /nitrogen-doped graphene (C-MoS 2 /N-G) integrated electrode via a hydrothermal-induced self-assembly process. The preformed carbon coated MoS 2 is strongly anchored on the porous nitrogen-doped graphene aerogel architecture. As an anode for lithium ion batteries, the C-MoS 2 /N-G electrode delivers a high first discharge capacity of 1600 mAh g −1 and maintains 900 mAh g −1 after 500 cycles at a current density of 200 mA g −1 . Impressively, superior high-rate capability is achieved for the C-MoS 2 /N-G with a reversible capacity of 500 mAh g −1 at a high current density of 4000 mA g −1 . Furthermore, the lithium storage mechanism of the obtained integrated electrode is investigated by ex-situ X-ray photoelectron spectroscopy and transmission electron microscopy in detail. [ABSTRACT FROM AUTHOR]