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Abstract A large number of coal water slurry gasification slag (CWSGS) was discarded annually in China due to the promotion of clean coal technology. The fine slag (F CWSGS) is abundant of silicates and unburned carbon. This research investigated the preparation of a porous carbon-silica composite (CSC) from F CWSGS using KOH activation followed by hydrochloric acid leaching. The orthogonal experiments showed that optimum parameters for preparing CSC were: activating at 1173 K for 1 h, hydrochloric acid concentration of 20%, leaching at 363 K for 30 min. The acid concentration was remarkable for total surface area and acid leaching temperature was remarkable for both total surface area and total pore volume while had few effect on micropore formation. The formation of micropore is a diffusion controlled process and the formation of mesopore is a chemical reaction controlled process. When the KOH/F CWSGS was 3, the prepared CSC had a BET surface area of 1347 m2/g, a total pore volume of 0.69 cm3/g, the mesoporosity of 81% and an average slit-liked pore diameter of 3.44 nm. Graphical abstract Image 1 Highlights • Fine coal water slurry gasification slag is a good source of raw materials for CSC preparation. • Acid leaching is simpler than sol-gel method for CSC preparation. • Silica fragment take parallel carbon micropores as template to form mesopores. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a statistical second-order two-scale (SSOTS) method is presented for predicting heat conduction performances of the structures of composite materials with inconsistent random distribution. Firstly, the meso-scopic configuration for the structure with inconsistent random distribution is characterized. Secondly, the SSOTS asymptotic formulation for predicting the heat conduction parameters and the temperature fields of the heat conduction problems of the structure is given by means of construction way. Then the heat conduction properties for the functional gradient materials (FGM) with varying volume fraction are predicted by the SSOTS method. The numerical results are compared with experimental data and theoretical results. Finally, macroscopic heat conduction properties for the structures with varying probability distribution models including size, location and orientation distributions of grains are calculated. The numerical results show that the SSOTS method in this paper is valid to predict heat conduction performances of composite structures with inconsistent random distribution. [Copyright &y& Elsevier]

A composite anode composing of in-situ exsolved Fe Ni alloy (FNA) nanoparticles and Ruddlesden-Popper perovskite SrLaFeO 4 (SLF) substrate has been prepared by reducing La 0.5 Sr 0.5 Fe 0.8 Ni 0.20 O 3-δ (LSFN) perovskite precursor in humidified H 2 (3% H 2 O) at 800 °C. Roles of FNA and SLF, respectively, in performance and stability of the anode are systematically studied. The electric conductivity of the reduced LSFN and single cell performance of the composite (SLF-FNA) are examined in comparison with those of the SrLaFeO 4-δ (SLFO 4 ) anode alone. The significantly improved performance of the composite anode cell at lower temperatures (<700 °C) may be predominately ascribed to the enhanced electrochemical activity as well as electric conductivity due to the presence of FNA exsolution. The maximum power densities (P max s) of a single cell with the composite anode achieve 0.74, 0.58, 0.40, and 0.25 W cm −2 at 800, 750, 700 and 650 °C, respectively, which is comparable to the performance of Fe Ni-SDC cermets anode. However, the long time stability of the composite anode is superior to that of the Fe Ni-SDC cermets in various fuels, suggesting that SLF-FNA is sulfur-tolerant and coking-tolerant composite anode material, which possess great potentials for future application. The results can be used as guidance for designing high-performance composite anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). [ABSTRACT FROM AUTHOR]

Abstract: A statistical second-order two-scale (SSOTS) method is established in a constructive way for predicting the thermomechanical properties of statistically inhomogeneous materials. For this kind of composite materials, the complicated micro-characteristics of inclusions, including their shape, size, orientation, spatial distribution, volume fraction and/or material properties and so on, lead to changes of the macroscopic thermomechanical properties, such as stiffness, coefficient of thermal expansion and strength of material. In this paper, a statistical model at an arbitrary position of the composite material is defined to represent the microstructure of the statistically inhomogeneous media at first. And then, the statistical second-order two-scale analysis formulation is derived. Finally, the numerical results for some statistically inhomogeneous composites are calculated by SSOTS algorithm, and compared with the data by experimental and theoretical methods. [Copyright &y& Elsevier]

The selective extraction of trace-level metal ions from unconventional sources such as wastewaters is a long-standing challenge, due to the large concentration difference between the target metal ions and the interfering ions in the matrix. We show here that an adsorbent based on crown ether functionalized mesoporous silica (MS-C-D) overcomes this limitation for selective sequestration of Ag(I) ion. This new adsorbent has hierarchical structure with large specific area and pore framework, which is conducive to the selective adsorption of trace levels of Ag(I) from a complex solution containing concentrated interfered ions such as Cu(II), Zn(II) and Pb(II) ions. The adsorption affinity (b value of 1.45) and selectivity coefficient (distribution coefficient K D of 1.50 * 10 5 mL/g) of Ag(I) by using MS-C-D were dramatically higher than many other reported adsorbents (e.g. an Ag(I)-ion-imprinted materials with K D of 392 mL/g) in literatures. Furthermore, the lower ion concentration corresponded to higher selectivity for Ag(I). The hierarchically structure of MS-C-D and the rigid cavity of dibenzo-18-crown-6 contributed to the selective adsorption of Ag(I). The adsorbent keeps high capacity (about 39.8 mg/g) and selectivity for Ag(I) adsorption after three regeneration cycles. This new composite adsorbent is promising in extracting trace levels of Ag(I) from unconventional wastewaters containing high concentrations of interfered ions. [ABSTRACT FROM AUTHOR]

With the help of polystyrene template, the indium oxide-titanium dioxide (In 2 O 3 -TiO 2) composite with a three-dimensional ordered macroporous (3DOM) structure was synthesized first, then cadmium sulfide (CdS) was loaded on the surface, and eventually 3DOM CdS/In 2 O 3 -TiO 2 composites were prepared. 3DOM CdS/In 2 O 3 -TiO 2 mainly presents the anatase structure of TiO 2 , while CdS and In 2 O 3 exist in the composite with low crystallinity. Compared with the monomer, the light absorption performance of the composite is significantly improved. The regular and well-organized three-dimensional ordered macroporous structure broadens the absorption of visible light, optimizes the charge transfer efficiency, and extends the photogenerated carrier life. The presence of heterojunctions in 3DOM CdS/In 2 O 3 -TiO 2 leads to enhanced performance of photodegradation and photolysis of water for hydrogen production. In particular, the hydrogen production of 3DOM CdS/In 2 O 3 -TiO 2 is 40.7 times that of the commercially available P25. Through the capture experiments, the possible photocatalytic reaction mechanism was speculated. [Display omitted] • 3DOM CdS/In 2 O 3 -TiO 2 was prepared by using polystyrene (PS) spheres as templates. • By combining CdS, In 2 O 3 and TiO 2 , a type II heterostructure was constructed inside the composite material. • The transmission path of light inside the catalyst was extended, resulting in the enhancement of light absorption capacity. • CdS/In 2 O 3 -TiO 2 composite showed well open 3DOM structures, which can enhance its photodegradation and water splitting. [ABSTRACT FROM AUTHOR]

The construction of heterostructures is considered as an excellent strategy to achieve efficient charge separation and enhance photocatalytic activity. In this paper, CoZnAl-LDH was first prepared by a temperature-programmed hydrothermal method. Then g-C 3 N 4 /CoZnAl-LDH composite was synthesized by loading g-C 3 N 4 in situ, followed by supporting In 2 S 3 on the surface of composite g-C 3 N 4 /CoZnAl-LDH. Finally, a novel dual S-scheme lamellar photocatalyst In 2 S 3 /g-C 3 N 4 /CoZnAl-LDH with ternary heterojunction was prepared. The crystal structure, morphology, composition and surface physicochemical properties of as-prepared photocatalysts were characterized by various testing methods. The results show that the lamellar In 2 S 3 /g-C 3 N 4 /CoZnAl-LDH composite mainly presents the characteristic structure of CoZnAl-LDH hydrotalcite compounds, and In 2 S 3 and g-C 3 N 4 are attached to the surface of CoZnAl-LDH. Compared with CoZnAl-LDH, the light absorption range of In 2 S 3 /g-C 3 N 4 /CoZnAl-LDH composite material is obviously broadened, and the specific surface area is increased. The results of multi-mode photocatalytic degradation of pollutants show that the photocatalytic degradation activity of In 2 S 3 /g-C 3 N 4 /CoZnAl-LDH composite with In 2 S 3 loading weight ratio of 40% is significantly higher than that of a single CoZnAl-LDH or g-C 3 N 4 /CoZnAl-LDH composite material. In addition, the composite exhibits enhanced photocatalytic hydrogen production capacity (404.78 μmol/g hydrogen production in 8 h, which is more than 6 times that of the monomer CoZnAl-LDH). Moreover, the photocatalytic activity remains stable after 3 cycles of experiments. The introduction of g-C 3 N 4 and In 2 S 3 on the CoZnAl-LDH matrix to form a dual S-scheme heterostructure is one of the main reasons for the enhanced photocatalytic activity. [Display omitted] [ABSTRACT FROM AUTHOR]

A MoSe 2 @g-C 3 N 4 was developed to suppress polysulfide shuttling and promote the adsorption-migration-conversion process in LSBs. [Display omitted] • The MoSe 2 @g-C 3 N 4 was fabricated for the first time as efficient functional interlayer for LSBs. • The dual-anchoring sites of Se-Li and N -Li bonding were built. • The shuttle effect was significantly suppressed even with a high sulfur loading. • g-C 3 N 4 is used as favorable adsorbent for LiPS, while MoSe 2 with a low migration barrier of LiPS. • MoSe 2 @g-C 3 N 4 with sulfur loading of 4.0 mg cm−2 achieves high specific capacity. The shuttle effect of lithium polysulfides (LiPS) and sluggish redox kinetic still restrict the commercial application of lithium-sulfur batteries (LSBs). Developing the modified functional separators that block the migration of LiPS and accelerate the LiPS conversion is an effective method to solve both problems. Here we report a MoSe 2 @g-C 3 N 4 composite material with the merits of strong adsorption in g-C 3 N 4 and appropriate migration in MoSe 2 for LiPS simultaneously achieved on the surface. g-C 3 N 4 has strong adsorption for LiPS while MoSe 2 with a low migration barrier of LiPS and improves their conversion into solid-state Li 2 S. The excellent wettability of MoSe 2 @g-C 3 N 4 facilitates electrolyte migration and improves the electrochemical performance. With a MoSe 2 @g-C 3 N 4 interlayer delivered 2.2 times increase initial capacity than that with a conventional polypropylene (PP) separator at 0.5C, and a low-capacity decay per cycle of 0.09 % was achieved at 0.5C after 500 cycles. It showed the best rate capability of 564.2 mA h g−1 at 3C. Even under the high sulfur loadings of 3.2 and 4.0 mg cm−2, showing high initial capacity and decent capacity retention. This project provides a novel insight into designing the functional separators with the g-C 3 N 4 substrate composites for stable LSBs. [ABSTRACT FROM AUTHOR]

Fe-doped SrMoO 4 (SrMo 0.94 Fe 0.06 O 4−δ ), synthesized by an EDTA–glycine complexing combustion process, can be easily reduced to SrMo 0.94 Fe 0.06 O 3−δ (SMF) at 850 °C in pure H 2 atmosphere. The incorporation of Gd 0.2 Ce 0.8 O 1.9 (GDC) into SrMo 0.94 Fe 0.06 O 3−δ is supposed to enhance the ionic conductivity and catalytic activity of SMF. Phase composition and chemical compatibility of SMF-GDC composite in both air and H 2 atmosphere are confirmed by X-ray diffraction test. SMF-GDC composites in different mass ratios are systematically investigated in terms of electrical conductivity, electrochemical performance and power output with the fuel cells. With the addition of GDC, the ionic conductivity is able to be improved and the lowest interfacial polarization resistance is observed to be 0.647 Ω cm 2 for SMF7-GDC3 composite anode at 850 °C. With SMF7-GDC3 as anode, the single cell is able to generate a maximum power density of 530 mW cm −2 at 850 °C when fed with pure H 2 (30 mL min −1 ) and demonstrates a considerable stability with the anode exposed to H 2 and upon redox cycling. [ABSTRACT FROM AUTHOR]

A facile, time-saving and one-step process to prepare graphene-based materials with excellent comprehensive capacitive performance is very promising for practical applications. Here, porous nitrogen-doped graphene/carbon nanotubes composite (PNGC) with loosened structure was prepared by pyrolysis method and the porous structure of PNGC was controlled by combined action of urea and low-cost lignosulfonate. PNGC is equipped with porous structure and thin graphene nanosheets, and meanwhile possess numerous active sites and high surface areas. Importantly, PNGC exhibits a high specific capacitance of 246.6 F g −1 at a current density of 0.5 A g −1 and high stability of 96.5% capacitance retention ratio after 2000 cycles at 100 mV s −1 , indicating an excellent performance of PNGC. Furthermore, the corresponding mechanism of pore formation in PNGC is hence proposed. This work of obtaining PNGC is of paramount importance for the future practical application of electrode materials for supercapacitor application. [ABSTRACT FROM AUTHOR]

The gram-scale synthesis of graphene based mesoporous SnO 2 composite (G-M-SnO 2 ) has been successfully realized based on kirkendall effect. When used as anode for lithium ion batteries, it delivers a high reversible capacity of 1354 mAhg −1 after 50 cycles at 100 mAg −1 and excellent rate capability of 664 mAhg −1 at 2 Ag −1 . The outstanding lithium storage performance mainly results from the synergistic effect of the ultrasmall SnO 2 and conductive graphene nanoparticles, which not only enhanced the conductivity of the whole electrode but also provide buffer matrix for the expansion of SnO 2 nanoparticles during charge-discharge process. Furthermore, the ultra-small size of SnO 2 shortens the diffusion length of Li + /e − in SnO 2 . [ABSTRACT FROM AUTHOR]

Highlights: [•] A polyoxometalate-based composite film decorated by CdS nanoparticles was fabricated by LbL technique. [•] Incorporation of CdS nanoparticles greatly improved electron transfer ability and electrochromic performance. [•] The composite film exhibited good stability, quick switching time and high optical contrast. [•] The mild electrolyte of pH 7 was used in the electrochromic process of the composite film, which is friendly to the environment. [Copyright &y& Elsevier]

Abstract: Cobalt alkoxide suspension is obtained by heating a mixed polyalcohol solution of cobalt acetate in an oil bath at 170°C. Thermogravimetric analysis is adopted to determine the chemical formula of the alkoxide powder in the suspension. With the suspension precursors, CoO/Co composite thin films are fabricated by electrostatic spray deposition and subsequent heat treatment in nitrogen. They are characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Electron energy loss spectroscopy mapping is applied to determine the lateral two-dimensional chemical distribution of metallic Co in the nanocomposites. The thin film can deliver a high reversible capacity of 1182.1mAhg−1 at 70th cycle and retain 69.5% of the initial capacity at 10C. The in situ production of metallic cobalt and the unique hollow structure of the particles can account for the good electrochemical performance. [Copyright &y& Elsevier]

Abstract: For the purpose of utilizing bamboo cellulose and providing a theoretical basis, the isothermal crystallization kinetics of modified bamboo cellulose/poly(ε-caprolactone) (MBC/PCL) composites has been investigated by differential scanning calorimetry (DSC) at different crystallization temperature (T c). The Avrami model was applied to describe the process of isothermal crystallization. According to Hoffman–Weeks theory, the values of the equilibrium melting point () increased with an increase in the content of MBC in the composites. The spherulite growth rate, the overall crystallization rate, the activation energy and folding-surface free energy (σ e) of PCL/MBC composites are markedly affected by the presence of MBC. According to Avrami theory, MBC accelerates the crystallization of PCL in the composites. However, as compared to neat PCL, all the composites of PCL/MBC had the higher σ e value. This indicates that there exist constraints on the mobility of the PCL chains in the interspherulitic regions due to the presence of MBC. [Copyright &y& Elsevier]

This review focuses on biomass-derived nanostructured carbons and their composites for lithium ion batteries, supercapacitors and polymer electrolyte membrane fuel cells. Electrochemical energy devices including batteries, supercapacitors and fuel cells are reliable and practical technologies in which carbon-based electrode materials play critical roles in enhancing performance. Because of this, the source and synthesis of these carbon-based materials have been extensively explored and developed. And of the various carbon-based materials, biomass-derived carbon materials and corresponding composites have been recognized to be capable of delivering high capacities, enhanced rate performances and prolonged cycling stabilities in both lithium-ion batteries and supercapacitors as partially induced through a combination of favorable pore structures and heteroatom-doping. In addition, biomass-derived carbon materials can provide significantly enhanced activity and stability for cathode oxygen reduction reactions if used as catalyst support materials in polymer electrolyte membrane fuel cells. Based on this, this review will provide a comprehensive assessment as well as critical analysis and systematic comparison of biomass-derived carbon materials and corresponding composites as electrode materials in various electrochemical energy devices based on recent progresses in research and development. In addition, related technical challenges are analyzed and possible research directions are proposed to further development for practical application. [ABSTRACT FROM AUTHOR]