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Reasonable construction of sulfur host with high conductivity, large sulfur storage gap, strong chemical adsorption, and fast oxidation-reduction kinetics of polysulfide is very significant for its practical use in lithium-sulfur batteries (LSBs). In this paper, the surface modification of MIL-88A(Fe) is carried out by Dawson-type polyoxometalate (POM), and a hollow capsule shell material with P2W18, Fe3O4, and C components is synthesized by the subsequent carbonization process. When applied as the sulfur host, the hollow capsule shell material can efficiently improve the conductivity of sulfur electrode and restrain the volumetric change of active sulfur while charging and discharging. On this foundation, electrochemical analysis and density functional theory (DFT) calculation show that the P2W18 on the outer layer of the capsule shell have effective electrocatalytic activity and potent chemical bond on the lithium polysulfides (LiPSs), which is helpful to block the shuttle effect. Therefore, the as-assembled LSBs display the outstanding specific capacity and prominent cycle stability. Specifically, it delivers an excellent reversible capacity of 1063 mAh/g after 100 cycles of charge–discharge at a rate of 0.5 C, accounting for a preservation by 96% in comparison to that of the initial cycle. Moreover, even after 2000 cycles at 1 C, the reversible specific capacity of 585 mAh/g can still be maintained with an average decay rate of only 0.021%.

The main bottleneck of photocatalytic H2 evolution is the high recombination rate of photoexcited electrons and holes. Herein, a novel composite comprising p-type AgFeO2 nanoparticles loaded on the...

For the design of atom-precise copper nanoclusters, besides the exploration of their aesthetic cage-like architectures, their structural modulation and potential applications are being extensively explored. Herein, an atom-precise 20-core copper(I)-alkynyl nanocluster (UJN-Cu20) protected by ethinyloestradiol ligands issynthesized. By virtue of outer-shell hydroxyl groups, UJN-Cu20 could be uniformly modified on the surface of TiO2 nanosheets via hydrogen bonding interactions, thus forming an efficient nanocomposite photocatalyst for hydrogen evolution. By constructing a Z-scheme heterojunction, the photocatalytic hydrogen evolution activity of the nanocomposite (13 mmol g−1 h−1) significantly improved as compared to that of TiO2 nanosheets (0.4 mmol g−1 h−1). As a narrow bandgap cocatalyst, UJN-Cu20 is confirmed to effectively inhibit the electron–hole recombination on the surface of the TiO2 nanosheet, which provides a new concept for the design of copper cluster-assisted effective photocatalysts.

Structural stability and rapid charge–discharge capability of electrode materials are required for high performance lithium-ion batteries (LIBs). The materials derived from polyoxometalates (POMs) show special advantages in inhibiting capacity attenuation, and good dispersion or combination of POMs with metal–organic frameworks (MOFs) is an important method to obtain high activity anode composites for LIBs. In this study, a uniform MoO2/MoS2 heterostructure with surface supported carbon (C-MoO2/MoS2) was successfully fabricated from a [Cu2(BTC)4/3(H2O)2]6[H3PMo12O40] precursor, which showed not only the designed octahedral morphology but also fast charge transfer, long working life, and high rate performance. Superior reversible lithium storage capacity of 1047 mA h g−1 after 300 cycles was obtained at 1 A g−1. Even after 700 cycles at 5 A g−1, the discharge specific capacity of 646 mA h g−1 was maintained, and rate capability of 610 mA h g−1 could be achieved at 10 A g−1. The high capacitive contribution could be explained by the relatively large specific surface area of porous C-MoO2/MoS2, which was mainly caused by the supported carbon network and MoS2 nanosheets, resulting in fast lithiation/delithiation processes.

Activated carbon particle electrodes modified by oxygen or nitrogen groups could be promising electrode candidates for capacitive deionization (CDI) processes. In this work, activated carbon particle electrodes were modified by phosphoric acid, nitric acid, urea, melamine, and zinc chloride to enhance desalination of an aqueous electrolytic solution. The modified activated carbon particles were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller measurements and electrochemical scanning. The electrodes with oxygen or nitrogen groups on the surface exhibited a much higher desalination capacity and charge efficiency than those without any surface modification. Particularly, the activated carbon particle electrode modified by phosphoric acid exhibited a desalination capacity of 15.52 mg/g at 1.4 V in 500 mg/L NaCl solution, which was approximately eight times that of the unmodified electrode (2.46 mg/g). The enhancement was attributed to a higher specific capacitance, a lower electrochemical impedance and an increase in oxygen or nitrogen-containing groups on the surface.

Herein, a new strategy for improving anti-corrosion performance of epoxy coatings has been developed, which combined halloysite nanotubes (HNTs) with graphene oxide (GO). On one hand, the corrosion...

To establish a nuclear resonant scattering beamline at the High Energy Photon Source (HEPS), it is essential to develop tools for detection and cleaning of parasitic bunches, for meeting the stringent demands on bunch purity. To this end, a novel time-correlated single-photon counting system was implemented at the electron storage ring of the Beijing Electron–Positron Collider II (BEPCII). The purity deterioration process over a week-long operation was recorded by the system. In this study, the mechanism of impurity growth was analyzed by numerical methods and validated on measurements. The agreement between the experimental results and the calculation was fairly good. Two main sources of parasitic bunches, pre-accelerators and the Touschek scattering were confirmed. A bunch-cleaning technique, based on a sinusoidal signal mixed with a pseudo-square wave, was also developed and implemented, and its capability to improve the bunch purity to the level of 10–7 was experimentally demonstrated. We present the experimental setup, principle, and measurement results of a system for detection and cleaning of parasitic bunches.

In this study, Pt-substituted polyoxometalate was first modified on the surface of commercially available TiO2, forming an efficient photocatalyst with high reactivity for hydrogen evolution. During the photocatalytic process, Pt-polyoxometalates not only increase the mobility rate of electrons but also improve the separation efficiency of photoinduced electrons and holes. After photoreduction, the in situ generated Pt0 species are anchored on the surface of polyoxometalate anion, which prevents further agglomeration. Then, the in situ formed Pt0 species and polyoxometalates synergistically promote the efficiency of photoinduced electron transfer from TiO2 to the protons adsorbed on the Pt0 surface. Although the content of Pt0 in the nanocomposite is only 0.6%, the photocatalytic hydrogen production rate reaches 5.6 mmol g−1 h−1 and remains stable at 4.5 mmol g−1 h−1 after the continuous catalytic process. Due to the modification of TiO2 by Pt-substituted polyoxometalate, this nanocomposite represents a practical model that possesses highly efficient photoelectric conversion performance. The presented work not only extends the family of new TiO2-polyoxometalate-based materials but also takes a further step toward the practical application of commercial TiO2 in photocatalytic hydrogen production.

A nano-structured hybrid compound was fabricated with excellent corrosion inhibitor encapsulating capacity and the ability of controlled delivery of benzotriazole (BTA) for simultaneous enhancement of the hydrophobic property and corrosion resistance of epoxy coatings. The Ce-metal organic frameworks (Ce-MOF) were synthesized and served as nanocontainers, tetraethyl orthosilicate (TEOS) was further added to form a film to wrap Ce-metal organic frameworks. The addition of benzotriazole into nanocontainers endowed coating system with excellent anti-corrosion performance. The novelty lies in that the tetraethyl orthosilicate membrane would break and produce pores to release benzotriazole uniformly under acid condition, which was a pH-controlled self-healing process through polymer coatings providing an effective release of corrosion inhibitor. The fabricated hybrid compounds were comprehensively characterized with Fourier Transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-vis), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrochemical Impedance Spectroscopy (EIS) was performed to characterize the corrosion behavior of various composite coatings. Results indicated that the 3 wt.%Ce-metal organic frameworks incorporated into the epoxy coatings showed the most excellent anti-corrosion property.

The strong interface interaction, especially interfacial charge transfer (CT) behavior, in TiO2/reduced graphene oxide (TiO2/rGO) nanocomposite endows the advanced hybrid material with extensive availability in dye-sensitized solar cells, photocatalysis, etc. Thus, revealing and understanding of the interfacial CT process are a crucial and interesting issue, owing to its vital contributions to optoelectronic and electronic properties. In this work, the TiO2/rGO nanocomposites with anchoring of TiO2 nanoparticles on rGO nanosheets have been fabricated, and a surface-enhanced Raman scattering (SERS) strategy with 4-mercaptobenzoic acid (4-MBA) as probe was performed to reveal the interfacial CT in the nanocomposites. There are obvious enhancements in the SERS intensity and the degree of CT (ρCT) in the 4-MBA/TiO2/rGO/4-MBA system compared with those of 4-MBA/TiO2 and 4-MBA/TiO2 + rGO/4-MBA (TiO2 + rGO is a physical mixture of TiO2 and rGO) due to the chemical interaction and the interfacial CT between TiO2 and rGO in the nanocomposite. It is indicated that the interfacial chemical interaction in the nanocomposite is an essential requirement for occurrence of the interfacial CT. The interfacial CT process can be evaluated quantitatively by the ρCT in SERS spectrum. The ρCT shows an obvious increasing trend with the increase of rGO amount in TiO2/rGO nanocomposites, and then reaches a saturation when the amount of rGO is 1.0%. And also, to further understanding of this CT progress, the model of the CT mechanism has been proposed. Furthermore, as-prepared TiO2/rGO nanocomposite can also be served as an effective SERS-active substrate for the ultrasensitive detection of analytes. The minimum detectable concentration of 4-MBA on the TiO2/rGO substrate can reach to 1 × 10−7 mol/L, which is comparable to a noble metal substrate. Even, for p-aminothiophenol target molecule whose SERS signals cannot almost be observed on the ordinary TiO2 substrate, the minimum detectable concentration can reach to a value as low as 1 × 10−8 mol/L on the TiO2/rGO substrate.

A ternary nanocomposite containing ZnO, ZnS and MoS2 (ZnMoNCs) has been firstly synthesized by Keggin-type polyoxomolybdate and ZIF-8 as starting materials to provide Mo and Zn sources simultaneously. As compared to the mono- or bi-component complex, ZnMoNCs present more sensitive and stable surface-enhanced Raman scattering (SERS) activity. When rhodamine 6G is used as a probing molecule, the detection limit of 10−9 mol L−1 can be achieved on the ZnMoNC substrate with the enhancement factor (EF) of 1.4 × 108, which is the highest sensitivity among the known semiconductor SERS substrates. The increased adsorption sites and the synergistically improved charge transfer are conducive to the large enhancement of the SERS activity. It was also proved that the ZnMoNC substrate possesses high stability and self-cleaning properties, and can be reused in SERS detection without losing its activity even after 5 cycles. This work paves a new way to the design of new semiconductor SERS substrates by the utility of a multicomponent complex.

Water splitting offers a clean way to produce hydrogen, in which, an efficient catalyst interface is one of the key factors to boot the activity and stability. Here, using polyoxotungstate (POT) as precursor, Pt-based bifunctional catalysts were fabricated, which are composed of Pt, WOx and graphene (Pt-WO3−x@rGO). The Pt-WO3−x@rGO (1.58% Pt-loading) catalyst shows an enhanced catalytic activity, namely, overpotentials of 37 mV for Hydrogen evolution reaction (HER) and 174 mV for Oxygen evolution reaction (OER), and achieves a working voltage of 1.55 V at 10 mA cm−2 for water splitting in alkaline-medium. Electrochemical analyses and DFT calculation suggest that the WOx mediated interface (Pt0⋅⋅⋅O − W) plays a key role to enhance the electron transfer and reduce the activation energy for both HER and OER. Moreover, this kind of Pt0⋅⋅⋅O − W interface enhances the Pt based catalyst stability in alkaline-medium significantly.

Separation membranes fabricated with graphene oxide, a kind of two-dimensional nanomaterial, have been extensively explored to achieve the separation purpose in water treatment. However, due to the natural hydrophily and compact stacked layer structure of the GO-based membrane, which usually has a low water flux and easily damaged. In this study, RGO@SiO2 nanohybrid has been fabricated successfully, and cooperated with dopamine to synthesize novel PVDF/RGO@SiO2/PDA nanohybrid membranes via a surface deposition method. Owing to the nanochannels created by the intercalation of SiO2 between graphene layers, the composite membranes were endowed with high flux and rejection rates in separation of oil-water emulsion and dye wastewater, and the surface morphology and structure of the membrane also improved. Besides, the deposition of dopamine (DA) on the membrane surface not only could firm the composite membrane, but an effective method to obtain an extremely hydrophilic surface, meanwhile this excellent hydrophilic surface was also beneficial for membrane to obtain an outstanding oleophobicity in water environment. More importantly, the novel membranes were successfully applied for the removal of oils and cationic dye from wastewater, which also exhibited a superior anti-fouling property and sustainable stability simultaneously. In summary, the PVDF/RGO@SiO2/PDA composite membranes could have a promising potential to be used as advanced separation membranes for water purification.

The CuS/Ag2S microspheres with reduced graphene oxide (CuS/Ag2S-rGO) composites have been successfully prepared via a hydrothermal method. The characteristic of CuS/Ag2S-rGO microspheres were chara...

Mg-Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. Results indicate that the 0.1wt% content of MgO catalyst has good performance on denitration activity and sulfur resistance. The effects of oxygen content, space velocity and reaction temperature on the activity of the 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst were investigated. With the increase of oxygen concentration, the denitrification efficiency increases when the oxygen concentration is less than 8%. When the oxygen content is greater than 8%, the denitrification efficiency is almost the same. The denitrification efficiency decreases with the increase of space velocity. The removal efficiency of NO 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst over increases first and then becomes stable with the increase of temperature, and the conversion efficiency of SO2 is less than or equal to 2.2% at 120~240 °C.

The concentration and distribution of bacteria-carrying particles (BCPs) in the operating room have an important influence on surgical site infections (SSIs). Local heating is commonly used during surgery to reduce the incidence of perioperative hypothermia (PH). However, the effects of local heating measures on airflow and BCPs have not been thoroughly studied. In order to study the effect of local heating in the operating room on airflow and BCPs, the experiment was carried out in the standard experimental operating room using Bacillus subtilis, and CFD numerical simulation was carried out using k-e turbulence model and Lagrange particle tracking model. The distribution of airflow and the concentration of BCPs in the operating room was studied in the four cases of no local heating (case 1), heating pad (case 2), warming blanket (case 3), and both heating pad and warming blanket (case 4). The results showed that local heating reduced the airflow rate above the patient's body, which also led to an increase in the concentration of BCPs. At T = 300 s, the concentration of BCPs above the operating table in Case 2, Case 3, and Case 4 was increased by 600 CFU/m3 and 260 CFU/m3 and 670 CFU/m3, respectively, compared with that without local heating. As time goes on, the increment of the concentration of BCPs caused by local heating decreases. It is recommended to use heating pad to keep patients warm from less influence on the concentration of BCPs and airflow distribution. This study provides a reference for reducing patients' SSIs and provides a basis for insulation methods.

Electricity generation in microbial fuel cells can be restricted by a few factors, such as the effective area of the anode for biofilm attachment, diffusion limitation of substrates and internal resistance. In this paper, a suspended anode (carbon-based felt granule)-type microbial fuel cell was developed to make full use of the volume of the anode chamber and provide a larger surface area of the anode for the growth of exoelectrogenic bacteria. The current collector was rotated in the anodic chamber to contact with the suspended granules intermittently and achieve better mixing. The open-circuit voltage reached steady state at around 0.83 V. The maximum power density obtained from each scenario increased steadily with the increase in mixing rate. The internal resistance decreased when the rotational rate and the content of the carbon granules were increased. The maximum power density reached 951 ± 14 mW m−3 with a corresponding minimum internal resistance of 162.9 ± 3.5 Ω when the mass of carbon granules was 50 g and the rotational rate was 300 rpm. The suspended microbes made negligible contribution to the power density. The microbial fuel cell with a higher content of carbon granules had lower coulombic efficiency and lower relative abundance of exoelectrogenic bacteria.

The electrocatalytic activities of a series of copper alloys, Cu/Ni/Zn (Cu60 Ni15 Zn25 ) and Cu/Zn (Cu62 Zn38 ), toward the reduction of nitrate were investigated, in comparison with that of pure copper. Electrochemical analysis showed that the copper alloy electrode exhibited higher electrochemical reduction rate of nitrate. The extreme difference (R) between the orthogonal experiments revealed that the NO3--N concentration was the main determinant of the removal percentage, followed by the current density and electrolyte concentration, while the impact of the initial pH was minimal. The conditions of the electrolysis experiments with Cu/Ni/Zn and Cu/Zn cathodes were optimized as follows: a current density of 8 mA/cm2 , a NaCl concentration of 2.0 g/L, and an initial pH of 3.0. The nitrate reduction reaction process with copper alloy cathodes was confirmed by electrochemical analysis and electrolysis experiments. Therefore, copper alloyed with Zn and Ni is a feasible option for practical application to the electrocatalytic reduction of nitrate. PRACTITIONER POINTS: Alloy of Cu, Zn, and Ni improved electrochemical nitrate reduction reaction. Electrochemical reduction of nitrate was confirmed in the presence of NaCl. The optimized current density with copper alloy cathodes was 6 mA/cm2 . A feasible strategy was provided for the improving nitrate removal and minimizing by-products.

One of the major challenges in the removal of organic pollutants is to design a material with high efficiency and high flux that can remove both cationic and anionic dyes, oil-in-water (O/W) emulsion and heavy metal ions. Herein, we constructed novel chemically stabilized MgAl-layered-double-hydroxide/sepiolite (MgAl-LDH/Sep) composite membranes via 3D hierarchical architecture construction methods. These membranes were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD), etc. Benefiting from the presence of hydrophilic functional groups on the surface of the film, the membranes show an enhanced water flux (~1200 L&middot, m&minus, 2 h&minus, 1), while keeping a high dyes rejection (above 99.8% for anionic and cationic dyes). Moreover, the CA membrane coupled with MgAl-LDH/Sep exhibits a multifunctional characteristic for the efficient removal of mesitylene (99.2%), petroleum ether (99.03%), decane (99.07%), kerosene (99.4%) and heavy metal ion in water due to the layer-by-layer sieving. This hierarchical architecture is proved to have excellent environmental and chemical stability. Therefore, the membrane has potential in the treatment of sewage wastewater.

In this work, a superhydrophobic MgAl-layered double hydroxide with F− intercalation (LDH-F) was fabricated by a facile method and further modification by stearate (St) anions. Then, the composite was dispersed in the epoxy resin to prepare anti-corrosion coatings, which was applied for corrosion protection of Mg alloy. This kind of coatings protects Mg alloy from some aspects. Firstly, the superhydrophobic film impedes the water molecules penetrating into Mg substrate. Secondly, the superior anions exchange ability of LDH can be used to stockpile chloride ions and the release of fluorine ions can react with magnesium ions to form a magnesium fluoride (MgF2) protective film at the corrosion area of the Mg alloy. Lastly, the LDH itself layered structure is a physical barrier. The fabricated composites were comprehensively characterized with Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), water contact angle (CA) and scanning electron microscopy (SEM). Electrochemical Impedance Spectroscopy (EIS) was conducted to investigate the corrosion behavior of various composite coatings and the results demonstrated that the impedance modulus of the superhydrophobic layered double hydroxide epoxy (LDH-F-St-EP) coating reached 1.2 × 109 Ω cm2, showing excellent anti-corrosion performances.

Recently, surface-enhanced Raman scattering (SERS) research based on semiconductor TiO2 has received increasing attention. However, the practical application of TiO2 SERS-active substrates has been hampered due to their lower surface performance and detection sensitivity. Here we report a new strategy to enhance the SERS activity of TiO2 nanoparticles (NPs) by means of formation of a mesoporous framework via reductive calcination of polymer coated nanocrystals. The 4-mercaptobenzoic acid (4-MBA) probe molecules on the mesoporous TiO2 substrate exhibit larger SERS enhancement compared with that on the ordinary TiO2 NP substrate; this considerable SERS enhancement mainly stems from the contributions of rich surface active sites of mesoporous TiO2, which can provide more effective adsorption sites for the molecules and promote the charge transfer between the substrate and the adsorbed molecule, and thus remarkably enhance SERS signals. On the mesoporous TiO2, a detection limit of 4-MBA as low as 1 × 10−8 mol L−1 can be achieved, which is the highest sensitivity among those reported for semiconducting substrates and even comparable with those of noble metal substrates. And, it is proved that the mesoporous TiO2 substrates are characterized by high stability and self-cleaning properties, and can be repeatedly used in SERS detection without losing their activity.

In this study, Au deposited TiO2 (Au-TiO2) nanocomposites were prepared by photocatalytic reduction of Au species (HAuCl4) on TiO2 nanoparticles (NPs) and served as efficient SERS-active substrates. The observed considerable SERS enhancement of 4-MBA molecules on Au-TiO2 NPs compared with that on pure TiO2 NPs can be attributed to the synergistic contribution of semiconductors and metals by the charge-transfer mechanism from the substrate to the molecule. In the preparation of Au-TiO2 nanocomposites, the photo-reduction time and concentration of HAuCl4 have an important influence on the SERS enhancement effect of the composite substrate. Moreover, for the recycle of substrates, the photocatalytic experiment of Au-TiO2 nanocomposites was carried out. The results show that these nanocomposite substrates are characterized by a self-cleaning property and can be repeatedly used in SERS experiments without losing their activity and with high stability.

A nanocomposite was fabricated with both excellent corrosion inhibitor encapsulating capacity and the ability of controlled delivery of benzotriazole (BTA) for simultaneously endowing coating systems with both active and passive anti-corrosion performances. The metal organic frameworks (MOFs) were synthesized and served as nanocontainers to load BTA. On this basis, tetraethyl orthosilicate (TEOS) was further added to form a film to wrap MOFs. The addition of TEOS endowed coatings with pH-responsive and active inhibition abilities, due to the film would break under acid or alkaline conditions. Moreover, the resultant compounds were further combined with graphene oxide (GO), cause GO had an superior barrier property and impermeability. On the other hand, there were abundant oxygen-containing functional groups on GO, which could be modified to improve the dispersion of GO in epoxy coatings. The fabricated nanocomposites were comprehensively characterized with Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Ultraviolet-visible spectroscopy (UV–vis) test was utilized to estimate the release behavior of BTA. Electrochemical Impedance Spectroscopy (EIS) was performed to characterize the corrosion behavior of various composite coatings. Results demonstrated that the BTA-MOF-TEOS-GO incorporated into the epoxy coatings showed the highest impedance values up to 8.6 × 108 Ω cm2, indicating the most excellent and durable anti-corrosion properties.

Efficient and noble metal-free co-catalyst loading is an effective solution for separating and transferring photo-generated carriers and lowering the overpotential in photocatalytic H2 evolution activity. In this work, we designed and prepared a series of novel NiCoP/Mn0.3Cd0.7S (NCP/MCS) composites by modifying MCS nanorods with the co-catalyst NCP using a simple calcination method. Notably, the 10-NCP/MCS composite displays the optimum photocatalytic H2 evolution rate of 118.5 mmol g-1 h-1 under visible-light irradiation. This is approximately 3.39 times higher than that of pure MCS. The corresponding apparent quantum efficiency is 10.2% at 420 nm. The superior photocatalytic activity of the NCP/MCS composites can be attributed to the efficient separation of photogenerated carriers caused by the intimate heterojunction interface between NCP and MCS, smaller transfer resistance, and lower overpotential of NCP. Moreover, the NCP/MCS composites exhibit remarkable photostability. A plausible mechanism is proposed.

With the purpose of preparing anticorrosive coatings, solvent-based epoxy resins often serve as raw material. Unfortunately, plentiful micro-pores are fabricated via solvent evaporation in the resin⿿ curing process, which is an intrinsic shortcoming and it is thus necessary to obstacle their micro-pore for enhancing antiseptic property. To reduce the intrinsic defect and increase the corrosion resistance of coating, we synthesize a series of SiO2⿿GO hybrids through anchoring silica (SiO2) on graphene oxide (GO) sheets with the help of 3-aminopropyltriethoxysilane and 3-glycidoxypropyltrimethoxysilane, and disperse the hybrids into epoxy resin at a low weight fraction of 2%. Furthermore, we investigate the appropriate preparation proportion of SiO2⿿GO hybrids (namely: SiO2⿿GO (1:5)). The electrochemical impedance spectroscopy (EIS) test and coatings⿿ morphology monitoring in corrosion process reveal that the anticorrosive performance of epoxy coatings is significantly enhanced by incorporation of SiO2⿿GO (1:5) hybrids to epoxy compared with neat epoxy and other nanofillers including SiO2 or GO at the same contents. The superiority of the SiO2⿿GO (1:5) hybrids is related to their excellent dispersion in resin and sheet-like structure.

The recoverable motion sensor with high sensitivity was made based on flexible self-healing nanocomposites. The preparation of these nanocomposites involved incorporating surface-modified CaCu3Ti4O12 (S-CCTO) nanoparticles in self-healing polymer matrix based on dynamic Diels–Alder (DA) adducts. The dependences of electric and dielectric properties of the resultant composites on volume fractions of filler and frequency were investigated. It is found that composites present a high dielectric permittivity of 93 at 100 Hz with 17 vol% filler, approximately 36 times higher than that of pure film. These results agree well with the percolation theory. Furthermore, the hybrid film recovers its capacitance well following a cut and the self-healing process based on DA and retro-DA (r-DA) reaction. We herein show that a polymer matrix based on dynamic DA adducts can be used to make self-healing high-K polymer nanocomposites and recoverable motion sensors. This work may lead to new opportunities for the design and fabrication of various next-generation wearable sensor devices.

This work reports the excellent dielectric properties of polyimide (PI) embedded with CaCu3Ti4O12(CCTO)/Ag nanoparticles (CCTO@Ag). By functionalizing the surface of CCTO nanoparticles with Ag coating, the dielectric permittivity of PI/CCTO@Ag composites is significantly increased to 103 (100 Hz) at 3 vol% filler loading. The enhancement of dielectric permittivity is attributed to the increment of conductivity of the interlayer between CCTO and PI by Ag, which enhances the space charge polarization and Maxwell–Wagner–Sillars (MWS) effect. The experimental results fit well with percolation theory. Moreover, the low loss (0.018 at 100 Hz) achieved is attributed to the blockage of charge transfer by insulating polyimide chains. It is shown that the electrical field distortion is significantly improved by decorating the surface of CCTO nanoparticles with Ag using Comsol Multiphysics. This plays an important role in the enhancement of the dielectric properties.

A novel electrochemical micromembrane technology coupling membrane and electric method was developed to demulsify oily wastewater and recover oil. The diameter of the oil droplets increased to 55.0 μm from the initial 7.0 μm after treating the emulsion with the electrochemical micromembrane technology. Chemical oxygen demand removal rate and oil recovery reached 87.89% and 5173 mg/L, respectively, after cycling for 90 min at 10.0 V voltage with a 10.0 mm electrode distance, a 5.0 μm micromembrane pore size and a 0.5 L/min flow rate. Micromembrane pore sizes of 1.0 and 5.0 μm were both effective for decreasing chemical oxygen demand and recovering oil. The recovered oil was the mixture of mineral oil and ester according to the Raman infrared spectroscopy analysis. Surface charge redistribution and electrogenerated destruction for hydrophilic groups of surfactant molecules are responsible for oil coalescence. The electrochemical micromembrane technology used in this study offer an attractive treatment option to demulsify oily wastewater.

The plasma was used to assist hemp fiber degumming. After degumming, the relationship of the hemp fiber fineness and chemical composition was analyzed through the Grey Relation Analysis. The results indicates that pectin content is bigger than hemicellulose and lignin content on the influence of hemp fiber fineness, and the influence of cellulose content is small. This conclusion is consistent with the actual production and the experience of technical personnel.The pectin, hemicellulose, and lignin are therefore the main content to be removed in the plasma assisted degumming.

Chemical adsorption of CO2 in composite cathodes at high temperatures plays a significant role in the electrochemical conversion of CO2 into fuels in efficient solid oxide electrolysers. In this work, the active Mn with multi-oxidation states is introduced into the B-site lattice of the redox-stable (La, Sr)TiO3+δ to create oxygen vacancies both in the bulk and on the surface. The ionic conductivities of the Mn-doped titanate are remarkably enhanced by 1–2 orders of magnitude at intermediate temperatures in reducing or oxidizing atmospheres. The chemical adsorption of CO2 is accordingly enhanced by approximately 1 order of magnitude for the Mn-doped titanate and the onset temperature of strong chemical desorption is consequently extended to as high as approximately 800 °C of the common operation temperature of solid oxide carbon dioxide electrolysers. First principles calculations reveal that oxygen vacancy defect sites created by Mn dopants substantially contribute to the chemical adsorption of CO2 and the strong bonding of the oxide ions in CO2 to the nearest cations on the (La,Sr)O- or (Ti,Mn)O2-terminated facets not only activates CO2 molecules but also considerably increases the desorption temperature. The highest current efficiencies of approximately 100% are obtained with the Mn-doped titanate cathodes for the direct electrolysis of CO2 in oxide ion-conducting solid oxide electrolysers.

The investigation was carried out to study the effect of a novel process of surface modification, surface nanocrystallization by high energy shot peening (HESP), on osteoblast proliferation and differentiation. A disc of pure titanium was processed to HESP in a commercial shot peening equipment, to create nanostructure at the surface. The surface microstructure was characterized by SEM and osteoblasts were co-cultured with the surface nanostructured titanium and unreceived titanium surface to evaluate their biocompatibility. The nanostructured surface layer on titanium was successfully processed by HESP, and the nanosized grains were about 60 nm in diameter and inhomogeneous distributed on the surface of n-Ti. The results also confirmed the proliferation and differentiation of osteoblasts were highly improved on surface nanostructured titanium. This finding suggests that there is high potential of this novel surface modification process which could enhance bone tissue growth of dental implant.

Crystallization is an important process in the pharmaceutical manufacturing industry. In this work, we report a study to create the zinc-free crystals of bovine insulin on a flow-free droplet-based platform we previously developed. The benefit of this platform is its promise to create a single type of crystals under a simpler and more stable environment and with a high throughput. The experimental result shows that the bovine insulin forms a rhombic dodecahedra shape and the coefficient variation (CV) in the size of crystals is less than 5%. These results are very promising for the insulin production.

Polyimide film has the weakness of high processing temperature and low corona resistance, which restrain its further development. Kapton 100 HN polyimide films with a thickness of 50 μm were aged by needle-plane electrode under 4 kV bipolar pulse voltages for 4 h at different frequencies (300—900 Hz). The surface morphologies of the pristine and aged polyimide films were analyzed using an atomic force microscope, and the changes in chemical bonds during corona aging were analyzed by Raman spectra. Different surface morphologies are observed using AFM, and the parameters all have sharp increases, which reveal that the surface morphology is obviously influenced by the corona aging under the bipolar pulse voltage. Raman results show that there are peak shifts and changes of the relative band intensities, which demonstrate that the chemical bonds in the polymer chains are reoriented by the electric field. Moreover, the corona aging of the polyimide film became severe at high frequency. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

The copyrolysis and cocombustion behaviors of Pingshuo coal and the biomasses (sawdust and rice straw) have been investigated using a thermogravimetric analyzer. The experimental results indicate that there exist synergetic effects between the biomasses and Pingshuo coal during their coconversion process. The initial temperature of volatile emission from Pingshuo coal and the temperature corresponding to the maximum conversion rate during the copyrolysis change with the biomass mixture ratio. Moreover, it can be deduced from the comparison between the experimental and the calculated DTG curves that the copyrolysis process is not the sum of Pingshuo coal and the biomass conversion. During their cocombustion process, the larger the mixture ratio of the biomass is, the lower the ignition temperature and the burnout temperature are, and the larger the combustion characteristic index is. In addition, the maximum combustion rate and the combustion performance are the best when the mixture ratio of the biomass i...

Ca1−x Rb x Cu3Ti4O12 (x = 0, 0.03, 0.05, 0.07 and 0.09) ceramics have been synthesized by the sol–gel method. The results of X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis indicate that a small amount of CuO and the grain boundary layers with Cu-rich and Ti-poor compositions are formed in the Rb-doped ceramic samples. The curves of dc electrical current density versus electric field strength have been collected at different temperatures, and the electrical conduction behaviors at grain boundary have been studied in detail based on the grain-boundary Schottky model. The results show that the formation of the Cu-rich and Ti-poor grain boundaries greatly affects the properties of grain-boundary Schottky potential barrier. For example, the barrier width increases with the increase on doping concentration x, and the barrier height (ФB) is also greatly enhanced as the concentration of dopants is very small, but as x is larger than 0.05, the ФB values reduce. These results should be ascribed to the second phases at grain boundary and the change of electronic structure.

The Kapton 100HN polyimide films were aged under 3 kV ac voltage (50 Hz), and the aging evolution were studied by the Fourier transform infrared spectroscopy (FTIR) and the dielectric measurement. The FTIR spectra show that the ether linkage, and some of C-H bonds in aromatic rings and C-N-C bonds transverse stretching vibration in imide are firstly broken by corona discharge. Then, with the increase of aging time, the cleavage of the imide group including C-N-C and C=O vibrations occurs. At the same time, the oxidative degradation produces compounds such as carboxylic acid, ketones, and aldehydes. Accordingly, the variations of dielectric constant e1 and the dissipation factor tan δ are dependent on the formation of the polar groups and the breakage of some polar bonds in polyimide.

Corona aging of 100CR polyimide (PI) film under bipolar pulse voltage was studied by using atomic force microscopy (AFM) and Confocal Raman microspectroscopy. AFM results show that the 100CR film near the breakdown hole is much rougher than the outside region. In the region away from the breakdown hole, no Raman shift is detected, but the intensity of all Raman peaks shows clearly decrease with the measuring region approaching more closely to the aging center. It is suggested that the damage of the PI film initiates from the surface in the presence of voids due to the partial discharge, and then gradually extends to interior, and these partial discharge cause progressive deterioration, and ultimately lead to the electrical breakdown of PI film with continuous aging.

Composite ceramics composed of the ferrimagnetic (FM) CoFe(2)O(4) and the anuferromagnetic (AFM) CoO were synthesized by using the chemical combustion method The characterization measurements including X-ray diffraction scanning electron microscopy and energy dispersive X-ray analysis show that CoFe(2)O(4) nano-particles are embedded in CoO matrix The magnetic measurements show that the hysteresis loops display a small negative exchange bias field (H(e)) of 106 Oe as the ceramic is cooled to 10K in an applied field of 10 000 Oe Furthermore the magnetic parameters including coercivity remanence and He show clear dependence on temperature and the applied magnetic field in the cooling procedures This exchange bias effect is ascribed to the exchange coupling at the FM/AFM interfaces (C) 2010 Elsevier B V All rights reserved

Ti1-xFexO2 nanocrystals with x = 0.01, 0.02, 0.03 were prepared via a nonaqueous synthesis route. X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy characterization confirmed the formation of anatase-phase nanocrystals with the average crystallite sizes of around 10 nm. The lattice constants alternate with the increase of the Fe content and no iron clusters were generated. X-ray photoelectron spectroscopy measurements showed that the substitutional Fe ions present mainly the valence of +3. The magnetic hysteresis loops measured at room temperature (RT) 300K showed that all the doped samples are atypically ferromagnetic, and the coercivity (Hc) of all the Fe-doping samples is around 0.1 T. An interpretation for the intrinsic RT ferromagnetism is put up based on the free carriers and defects induced interaction between Fe3+ ions.

Cobalt ferrite nano-particles were prepared using the co-precipitation method followed by annealing treatment. The formation of nano-particles with different composition, microstructure and sizes were confirmed by X-ray diffraction, Raman, thermogravimetric-differential thermal analysis and transmission electron microscope. The magnetic hysteresis loops measured at room temperature revealed smaller effective magnetic anisotropy constant, coercivity and remanence ratio for the samples prepared by adding the NaOH solutions into the mixed solutions of Co(2+) and Fe(3+) ions due to the formation of Co(3+) ions. A small saturation magnetization and an enhanced coercivity were observed for the nano-particles prepared by adding the mixed solutions of Co(2+) and Fe(3+) ions into the NaOH solutions, which was related to the formation of outer layers with poor crystallization on the surfaces of the cobalt ferrite nano-crystals. Furthermore, the existence of these outer layers induced the oxidation of Co(2+) ions in cobalt ferrite nano-crystals at 200 and 300 degrees C, and led to a large change on the composition and magnetic properties. (C) 2010 Elsevier B.V. All rights reserved.

We have successfully prepared magnetic frustrated compound Mg[Ti2]O4 by a novel technique of spark plasma sintering. X-ray diffraction confirms that the sample is single phase and the spinel parameter a = 8.504(7) A at the room temperature. The magnetic susceptibility shows that an abnormal drop is exhibited at about 254 K, indicating a magnetic single formation, and that a paramagnetic susceptibility increase which obeys the Curie Law appears below about 150 K, revealing that the number of Ti3+ ions which don't take part in spin dimer is about 2.6%. The resistivity shows a jump at the temperature of 254 K, in agreement with the transition temperature of measurement of the susceptibility.

Recently, a high-pressure phase (B2) of KI has been experimentally observed in the inner space of single-walled carbon nanotubes. Our first-principles calculations indicate that in a confined nanospace, relative stabilities of the high-pressure B2 phase and the low-pressure B1 phase of KI are not necessarily determined by their external pressures. As a result of crystal symmetry differences, different phases are preferred at different K/I ratios. Such a symmetry-recognized confinement effect opens a new avenue for nanomaterials synthesis.