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CuS/ZnS/sodium alginate/reduced graphene oxide nanocomposites (CZSrG) were prepared by physical crosslinking followed by one-step reduction and were justified as green binder-free hydrogel high-capacitance electrodes. The physical crosslinking was realized simply through the hydrogen-bond interaction between sodium alginate (SA) and graphene oxide (GO), avoiding the usage of traditional Ca2+ crosslinking agent. The hydrogel structure made of CZSrG possessed the most beneficial effect of avoiding large volume change and increasing cycle stability for supercapacitors. When used as electrode, the specific capacitance of CZSrG was 992 F·g−1 (10 mV·s−1) in a three-electrode system. Furthermore, the fabricated supercapacitors had a specific capacitance of 252.1 F·g−1 (5 mV·s−1), and a power density of 1800 Wh·kg−1 at the energy density of 2.05 Wh·kg−1. Thus, the CZSrG has a favorable electrochemical performance and wide application prospects in supercapacitors.

To improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

Polyacrylamide (PAM) has been used as a coagulant aid in water treatment process for past decades, but it has caused great damages to human nervous system. Developing new coagulant aid with high biological safety is urgently demanded. This study provides a natural biomacromolecule coagulant aid with good biosecurity-Enteromorpha prolifera polysaccharide (Ep). Its coagulant aid efficiency and mechanism were investigated in terms of organics removal, floc properties and membrane fouling degree. In addition, contrast experiments were conducted with PAM to evaluate its potential of industrial applications. Results showed that organics removal could be increased by 23% when 0.3 mg/L Ep was used, which exhibited comparable aid effects to PAM. Due to the bridging-sweep aid role of Ep, flocs sizes, growth rate and recovery factor reached 470 μm, 62.6 μm/min and 0.492, respectively, while only 170 μm, 14.0 μm/min and 0.326 were obtained by PAM. Additionally, flocs exhibited more porous and multi-branched structures when Ep was applied, which caused less ultrafiltration membrane fouling (eventual J/J0 value = 0.52). As a result, Ep could be considered as a potential substitute of PAM, since better biosecurity, higher organics removal and lower membrane fouling could be obtained simultaneously by Ep addition.

Hypothesis Cellulose aerogels are a new category of high-efficiency adsorbents for treating oil spills and water pollution. However, the hydrophilic properties and recyclability of aerogels after adsorption hamper developments and applications. Combining both hydrophobic and magnetic properties are expected to improve their adsorption capacity and functionality. Experiments In this study, the effect of oleic acid (OA) and nanomagnetite on the preparation of magnetic nanocellulose aerogels (called as NCA/OA/Fe3O4) by a mechanical mixing combined with freeze-drying method have been investigated. Findings It has been found that the optimal condition for fabricating this NCA/OA/Fe3O4 aerogel is 0.4 wt% nanocellulose, 3 mg mL−1 OA and 0.5 wt% Fe3O4 in the aqueous solution. This aerogel has a very low density of 9.2 mg cm−3 and demonstrates a high adsorption capacity of 68.06 g g−1 for cyclohexane. In addition, this aerogel adsorbent demonstrates an excellent magnetic responsivity and can be easily recycled by a permanent magnet after adsorption. As a consequence, this hydrophobic magnetic NCA/OA/Fe3O4 aerogel is promising not only for easy oil and organic solvent adsorption but also potentially for other magnetic related applications.

The nano-oxide materials with special structures prepared by template methods have a good dispersion, regular structures and high specific surface areas. Therefore, in some areas, improved properties are observed than conventional bulk oxide materials. For example, in the treatment of dye wastewater, the treatment efficiency of adsorbents and catalytic materials prepared by template method was about 30 % or even higher than that of conventional samples. This review mainly focuses on the progress of inorganic, organic and biological templates in the preparation of micro- and nano- oxide materials with special morphologies, and the roles of the prepared materials as adsorbents and photocatalysts in dye wastewater treatment. The characteristics and advantages of inorganic, organic and biological template are also summarized. In addition, the applications of template method prepared oxides in the field of sensors, drug carrier, energy materials and other fields are briefly discussed with detailed examples.

Carbon nanotubes (CNT)-cerium oxide (CeO2) nanocomposites were fabricated successfully by one-pot microwave hydrothermal growth of regular CeO2 nanoparticles with a size of 8 nm on hydroxyl-functionalized multi-walled CNTs. These nanocomposite photocatalysts demonstrated an acid orange (AO7) photocatalytic degradation efficiency of above 90% under solar-simulated light irradiation for 3 h, which was much higher than that of the pure CeO2 nanoparticles. The enhanced photocatalytic activity was observed to mainly originate from the ˙O2- and hole traps, while the hydroxyl radical ˙OH played a secondary role.

In this study, carbon dot-sensitized Ti3+ self-doped TiO2 dual-phase (TiO2−x/CDs) composite photocatalytic systems were successfully constructed using a low-temperature hydrothermal method. The TiO2−x photocatalyst showed improved photocatalytic activities for the removal of Cr6+ and RhB under visible light. Remarkably, RhB (10 mg L−1) and Cr6+ (40 mg L−1) solutions were degraded completely in 30 and 120 min, respectively, by the composite photocatalyst (1 g L−1) under visible-light irradiation. These results were much better than those of commercial P25. This fascinating photocatalytic performance was attributed to the improved photogenerated electron–hole separation efficiency from the synergistic effects of rutile and anatase, and the reduced photogenerated charge carrier recombination and facilitated visible-light absorption from the introduced CDs. This study provides a promising approach for the treatment of real wastewater using sunlight.

Bismuth oxychloride (BiOCl) and cerium dioxide (CeO2) composites were successfully synthesized via a facile one-step co-precipitation method. The BiOCl/CeO2 composites were observed to be sheet-like structures with some CeO2 nanoparticles distributed on the surface. The BiOCl/CeO2 composites exhibited higher photodegradation performance (98.8%) of rhodamine B (RhB) than pure BiOCl (80.2%) and CeO2 (9.6%) under solar simulated irradiation. The BiOCl/CeO2 composites with a Bi/Ce molar ratio of 4 : 1 exhibited the highest photocatalytic performance for RhB, and an optimal RhB degradation efficiency of 98.8% was achieved under solar simulated irradiation for 60 min. The photocatalytic performance results were compared with other BiOCl composites. The photocatalytic mechanisms of BiOCl/CeO2 composites were discussed by radical trapping experiments and electron spin resonance (ESR), which indicated that h+ and ˙O2− were the dominant radicals for RhB degradation.

Excess sludge, a carbon-rich valuable by-product from wastewater treatment, is utilized as a carbon precursor for synthesizing porous activated carbon. However, improving specific surface area (SBET) is the main challenge for the sludge derived activated carbon (SAC). In this study, the carbonization process was optimized as following: carbonization temperature of 900 °C, heating rate of 10 °C/min, and dwell time of 30 min. Moreover, the residue heavy metals and bound water remaining in the sludge were demonstrated to be important in the pore formation of the SAC. The metals acted as hard template to form the pores in the SAC after the metals were removed by acid wash. The bound water was found to be soft templates for forming pores due to its evaporation during carbonization. A maximum SBET of 1018.8 m2/g was achieved for the SAC when the bound water content was controlled at 2 wt%.

Practical applications of lithium–sulfur batteries have been impeded by their poor cycling stability that results from the “shuttling” of polysulfides. Herein, we demonstrate a new strategy for developing a hierarchical phosphorus-doped graphene/carbon nanofiber/sulfur aerogel (PGCNF/S) with “network” morphologies, in which sulfur spheres are wrapped with graphene sheets and carbon nanofibers (PGCNFs) with “net” structures and this carbon matrix has greatly improved the electrochemical performances of sulfur spheres. PGCNF nets ensure a uniform loading of sulfur spheres that leads to a high sulfur mass loading of 85 wt%. Also, the good porous structures achieved with this PGCNF/S cathode can provide sufficient space for volume expansion of active sulfur spheres. Due to its structural advantages, this binder-free PGCNF/S cathode exhibits a specific capacity of 1360 mA h g−1 at 0.1C, and a high areal capacity of 21.5 mA h cm−2 based on a high sulfur mass loading of 15.8 mg cm−2. Furthermore, a long term cycling stability of 600 cycles has been achieved by this PGCNF/S cathode with an average coulombic efficiency of ∼99.8%. This work highlights a broadly adaptable strategy of “network” structures for developing scalable and high-energy density electrode materials for energy storage devices.

In this work, natural polysaccharide product sodium alginate (SA) served as templates to prepare porous calcium silicate (CS) hydroxyapatite (HA) composite microspheres (CHCM) with high specific surface area by a new route combining ion exchange and calcination. CHCM played an important role in the fields of environmental protection with its large specific surface area, excellent adsorptive property, high mechanical strength and good regeneration performance. In order to explore its treatment capacity of wastewater, a series of eriochromeblue black R (EBBR) adsorption experiments were carried out. The equilibrium data fitted well with the Langmuir isotherm with a maximum adsorption capacity of 76.80 mg/g. Electrostatic interaction, ionic bonds and physical adsorption were responsible for the interactions between the EBBR and CHCM. Meanwhile, the CHCM maintained complete spherical and almost undamaged in the regeneration experiments, which confirmed its stability for cyclical usage. This paper demonstrates the role of natural polysaccharide product sodium alginate serving as templates to prepare useful products with potential wide applications.

Low-cost natural polymer lignin has been widely used to remove heavy metal ions from polluted water. But it still has some shortcomings, such as poor removal performance, and weak selective adsorption. Thus, in this study, the lignin prepared by Mannich reaction with black liquor was activated with triethylenetetramine (TETA) to achieve a novel adsorbent with high adsorption rates and a strong selectivity for specific oxygen-containing anions. The adsorption capacity of activated lignin (a-CL) on three oxygen-containing anions (i.e. As(V), P(V) and Cr(VI)) was investigated systematically. The adsorption mechanism of a-CL was elucidated theoretically by the density functional theory (DFT) method. Under the same conditions, the selectivity toward oxygen-containing anions by a-CL followed P(V) Cr(VI) As(V). Both FT-IR and DFT simulation results revealed that the hydrogen bond between HAsO

Three-dimensional graphene (3D-GN)/Cu/Fe3O4 composite support materials were synthesized by a modified chemical reduction method using graphene oxide precursor. A 3D-GN/Cu/Fe3O4 biosensor was prepared by coating the electrode with laccase. The electrochemical properties of the biosensor were investigated by cyclic voltammetry (CV) and differential pulse voltammetry using potassium ferricyanide, phosphate-buffered saline (PBS) solution, and bisphenol A (BPA) solution. The current response of 3D-GN/Cu/Fe3O4 biosensors presents a remarkable sensitivity based on CV. The linear range of BPA is 7.2–18 µM using differential pulse voltammetry in PBS solution (pH = 4.0). A linear fitting equation of the laccase biosensor was observed for the current response as a function of BPA concentration. The detection limit was decreased to 1.7 µM. The detection approach herein turns out to be highly sensitive, has a wide linear range, and exhibits excellent stability.

Thermal expansion coefficient (CTE) is a critical parameter of gun propellant because of its major role in fabrication, storage and combustion performance of the propellant. Further, controlling the CTE of the propellant is an effective solution to improve its loading density. Therefore, it is important to understand the thermal expansion of the propellant. To obtain the linear CTE of insensitive gun propellant, different weight percentages of NQ are added to the B# double-base absorbent propellant, the thermal mechanical analyzer (TMA) is employed to estimate their dimensional change over the temperature range of 213–323 K. The pure NQ flaky gun propellant exhibits a negative thermal expansion with a linear CTE of −2.006 × 10−4 mm/mm K−1. The results show that the linear CTE of the B# double-base absorbent propellant is decreased by 53.74% as the concentration of NQ is increased to 30%, whereas the glass transition temperature increases with increasing the NQ content. Keywords: Flaky gun propellant, Coefficient of thermal expansion (CTE), Negative thermal expansion, Nitroguanidine (NQ), Glass transition temperature

Porous grafted copolymer with excellent thermal stability and swelling capacity was synthesized from water soluble Prunus cerasifera gum polysaccharide (PG) and acrylamide (AM). The monosaccharide compositions and the structure of Prunus cerasifera tree gum were detected by a high-performance anion exchange chromatography (HPAEC) system and 1H NMR and 13C NMR, and the obtained PG-AM copolymer was characterized by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The results indicated that the water soluble polysaccharides obtained from Prunus cerasifera tree gum were mainly composed of l-arabinose (39.78%) and d-galactose (40.59%) with minor amount of xylose, mannose and uronic acids. The maximum percent and the grafting efficiency of grafting acrylamide (AM) onto PG to form PG-AM were obtained by copolymerization between polysaccharide and 3 times (weight) acrylamide with 3 mmol/L potassium persulfate initiator at 50 °C for 1 h. In addition, lots of isolated and conjoint pores were observed in the prepared PG-AM materials, with a diameters distribution between 2 and 10 μm. Compared with PG, the synthesized copolymer PG-AM showed an excellent performance in thermal stability and swelling capacity. The detailed structural characteristic together with excellent thermal stability and swelling properties will benefit efficient utilization of the synthesized copolymer as a precursor for preparation of large-scale environmentally friendly advanced materials with various potential applications.

Low photocatalytic efficiency of visible light and fast recombination of photo-generated carriers are two challenges facing the applications of photocatalyst sterilant zinc oxide (ZnO). Meanwhile, both light and dark photocatalytic activities are important. It is of great theoretical and practical significance to construct a day-night photocatalytic antibacterial material, which is beneficial to the effective use of energy and to tackle the limitation of using photocatalytic bacteriostat. ZnO nanoflowers decorated vanadium pentoxide (V2O5) nanowires heterojunction (ZVH) was firstly fabricated using a facile water-bathing method. The designed ZVH structure efficiently produced abundant reactive oxygen species (ROS) in both light and darkness. It yielded 99.8% and 99.0% of antibacterial rate against S. aureus due to oxidative stress induced by ROS in light and darkness, respectively. The generation of ROS played a major role in the antibacterial activities against S. aureus under both light and dark conditions. The prepared ZVH with improved antibacterial properties provides an alternative for day-night antibacterial agents.

Graphene presents an extremely ultra-high thermal conductivity, well above other known thermally conductive fillers. However, graphene tends to aggregate easily due to its strong intermolecular π-π interaction, resulting in poor dispersion in the polymer matrix. In this study, silver nanoparticles anchored reduced graphene oxide (Ag/rGO) were first prepared using one-pot synchronous reduction of Ag

Biochar conversion from corn stover was evaluated under various process conditions, and the absorption capacity of biochar was investigated for the removal of oxytetracycline in wastewater. Biochar was prepared at lower carbonization temperatures (200–500 °C) and was used in three different concentrations of chemical oxygen wastewater. The results showed that the biochar prepared at the temperature range of 200–500 °C had a faster sorption rate and shorter sorption equilibrium time compared to biochar produced at higher temperatures. The longest time to reach sorption equilibrium was 9 h for biochar obtained at 200 °C. However, the biochar prepared at 500 °C required only 0.5 h to reach the sorption equilibrium. The corn stover-biochar had the highest sorption capacity of 246.3 mg/g for oxytetracycline at 30 °C. The adsorption kinetics was consistent with pseudo–second-order kinetics. This study provides a theoretical basis for the conversion of corn stover into biochar as efficient sorbents.

A polyvinyl butyral (PVB)/graphene oxide (GO) nanocomposite coating was prepared via spin coating method to improve the anticorrosion ability of aluminum alloy. Poly (methylhydrosiloxane) (PMHS) has been innovatively applied as anti-corrosion coatings of aluminum substrate owing to its hydrophobicity. The properties of the coating were characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and other methods. Meanwhile, the corrosion resistance of the coating in 3.5 wt% NaCl solution was estimated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The SEM observations showed that the coating was uniformly distributed on the surface of aluminum. EIS tests showed that the coating had a remarkable anticorrosive effect on the metal surface. Compared with bare aluminum, the low frequency impedance modulus improved three orders of magnitude, reaching 107 Ω cm2. The polarization curve showed that the corrosion current density (Icorr) decreased more than three orders of magnitude, reaching 7.8 × 10−9 A cm−2. The long-term immersion experiment indicated that the coating could effectively protect the aluminum for up to 1200 h. This study provides a facile way of using polymer nanocomposites to tackle the corrosion of aluminum alloy for industrial applications.

Dopamine modified aramid fiber (AF) surface was grafted with amino functionalized graphene oxide to improve the interfacial adhesive performance. The self-polymerized polydopamine (PDA) coating and subsequent amino GO grafting on the AF surface attributed to the increase in its surface roughness and surface-active groups. The functional groups, chemical composition and surface topography of unmodified and modified AF was investigated by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM). The interfacial properties were analyzed by measuring interfacial shear strength (IFSS) of unmodified and modified AF embedded epoxy matrix. Further, the properties were tuned by optimizing the reaction temperature and concentration of ethylenediamine. The IFSS of AF/epoxy composites was increased by 34% after grafting amino graphene oxide.

A series of TiO2/ZrO2 composites with various molar ratios of ZrO2:TiO2 were synthesized by a facile and mild microwave hydrothermal method with carboxymethyl chitosan (CMCS) as templates. The as-obtained products were characterized with wide-angle powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), UV–vis diffuse reflectance spectrophotometry (UV–vis-DRS), N2 adsorption-desorption isotherms (BET), and X-ray photoelectron spectrometer (XPS). The TiO2/ZrO2 composites with heterogeneous structure consisted of particles which showed a better regularity and uniform with about 800 nm in diameter, and showed a larger specific surface area and smaller energy band gap than pure ZrO2. Comparative experiments including varying the pH of the solution and the content of titania demonstrated that the 5% TiO2/ZrO2 composites ( n T i : n Z r = 5:100) at pH = 10.3 possessed the best photocatalytic property. Moreover, the possible reasons for these phenomena were clarified. Cyclic experiments proved that the resulting TiO2/ZrO2 composites as photocatalyst could be reused efficiently. Meanwhile, a possible mechanism of photocatalysis was proposed.

ObjectiveTo study the function of the RNA-binding protein Hfq in Bacillus subtilis cellulose decomposition.ResultsIn the medium with sodium carboxymethylcellulose (Na-CMC) as the sole carbon source, the knockout of Hfq resulted in a 38.0% ± 2.1% and 76.6% ± 7.1% decrease in cellulose hydrolysis ability and cellulase activity, respectively. The results of real-time quantitative PCR revealed that several cellulase genes (eglS, bglA, and bglC) were significantly downregulated in the Hfq knockout strain. The isogenic ΔHfq complemented strain recovered the cellulose hydrolysis ability, cellulase activity, and expression level of cellulase genes. In addition, the survival of Hfq mutant in stationary phase was significantly affected. ConclusionRNA-binding protein Hfq is involved in the regulation of cellulose hydrolysis ability, cellulase activity, cellulase gene expression, and stationary phase survival.

To study the function of the RNA-binding protein Hfq in Bacillus subtilis cellulose decomposition. In the medium with sodium carboxymethylcellulose (Na-CMC) as the sole carbon source, the knockout of Hfq resulted in a 38.0% ± 2.1% and 76.6% ± 7.1% decrease in cellulose hydrolysis ability and cellulase activity, respectively. The results of real-time quantitative PCR revealed that several cellulase genes (eglS, bglA, and bglC) were significantly downregulated in the Hfq knockout strain. The isogenic Δhfq complemented strain recovered the cellulose hydrolysis ability, cellulase activity, and expression level of cellulase genes. In addition, the survival of Hfq mutant in stationary phase was significantly affected. RNA-binding protein Hfq is involved in the regulation of cellulose hydrolysis ability, cellulase activity, cellulase gene expression, and stationary phase survival.

C-doped ZnO particles have been successfully prepared by the calcination using microwave hydrothermally prepared metal-organic framework-5 (MOF-5) as the precursor. MOF-5 was turned into C-doped ZnO through calcination at 500 °C, and its cubic shape was well-maintained. X-ray photoelectron spectroscopic studies confirmed the C-doping in the ZnO. The as-prepared C-doped ZnO demonstrated a Rhodamine B (RhB) degradation efficiency of 98% in 2 h under an solar-simulated light irradiation, much higher than that of C-doped ZnO derived from MOF-5 synthesized by the ordinary hydrothermal method. The trapping experiment revealed that the crucial factors in the RhB removal were photogenerated h

Conductive Nb12O29 hierarchical microspheres with nanosheet shells were synthesized based on a hydrothermal process and a high-temperature hydrogen reduction treatment. The obtained materials demonstrated comprehensively good electrochemical properties, including a significant pseudocapacitive contribution, safe operating potential, high reversible capacity, superior initial coulombic efficiency, increased rate capability, and durable cycling stability.

For effective hydrogen generation with remarkable durability, carbon nanotubes (CNTs) grown on Ni nanofibers and their post hydroxylation treatment engendered active Ni nanofiber catalysts an efficient decomposition of hydrous hydrazine with a turnover frequency (TOF) of 19.4 h-1 and an activation energy down to 51.05 KJ mol-1.

Despite adopting diverse strategies and fabrication methods to prevent biofilm formation, the existing sophisticated fabrication methods for sole wettable or smart surfaces and their unsatisfactory anti-adhesive durability need to be improved for their practical applications. In this study, a new anti-biofilm strategy via spraying bacterially-anti-adhesive modified polystyrene (MPS)/Ag microspheres was proposed to construct two kinds of bacterially-anti-adhesive surfaces with tunable wettability to meet different requirements in various fields. These surfaces could be constructed on arbitrary surfaces of materials and devices by this facile spray-coating method. A hydrophilic-type surface was demonstrated to possess superior antibacterial and bacterially-anti-adhesive capabilities. More importantly, its bacterially-anti-adhesive mechanism was first illustrated by molecular dynamics (MD) simulations of the resisting effect of the hydrated layer. These surfaces could be easily converted to hydrophobic-type surfaces with significantly enhanced bacterially-anti-adhesive properties. It is worth noting that underwater oleophobicity was first deemed to be a vital factor for bacterial anti-adhesion due to the lotus-like repelling effect, in addition to the outstanding self-cleaning properties and repellency of surfaces for various bacterial media. The contact/release-killing synergistic antibacterial model and resisting and repelling bacterially-anti-adhesive model were, thus, substantially elucidated. Importantly, these surfaces demonstrated an outstanding durable and robust resistance to mechanical damage and chemical attack. This fabrication method is expected to be flexibly applied to arbitrary substrates in practical fields.

The structures and mechanical properties of Nb-Mo-Co(Ru) solid solutions for hydrogen permeation have been investigated by X-ray diffraction (XRD) analysis, pressure-composition-temperature (PCT) measurements, and three-point bending tests. The as-prepared Nb86Mo14, Nb86Mo7Co7, and Nb86Mo7Ru7 samples composed of Nb-based solid solutions with bcc structures were hydrogenated into their corresponding hydrides to give the NbH0.95 phases after hydrotreatment. The largest lattice deformations of the bcc structure and NbH0.95 phase were observed in the Nb86Mo7Ru7 sample. This sample possessed the highest hydrogen-diffusion coefficient value (2.32 × 10−9 cm/s), the lowest hydride formation enthalpy (−21.4 kJ/(mol·H2)), and the maximum force before and after hydrogenation. Overall, these results demonstrate that the addition of Ru improves hydrogen diffusion and enhances the mechanical properties of Nb86Mo14 alloy against hydrogen embrittlement.

Three-dimensional magnetic graphene oxide-magnetite polyvinyl alcohol (3D-GO/PVA/Fe3O4) nanocomposites were successfully prepared. The morphology was characterized and analyzed through scanning electron microscope (SEM) and transmission electron microscope (TEM). The chemical structure and the crystal structure were explored by X-ray powder diffraction (XPS), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction spectra (XRD). The magnetic property was obtained by vibrating sample magnetometer (VSM). The specific surface area and the average pore size were determined by Brunauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH). The specific surface and the average pore size of 3D-GO/PVA/Fe3O4 nanocomposites were 388.87 m2g-1 and 9.6 nm, and the higher specific surface indicated that the three-dimensional structure avoided the aggregation for GO sheets. The large saturation magnetization (Ms) of the nanocomposites of 30.5 emu/g enabled the easy cycling of the nanocomposites. The 3D-GO/PVA/Fe3O4 nanocomposites exhibited better performance for porcine pancreatic lipase (PPL) enzyme immobilization. The maximum immobilization efficiency was 91%, and the enzyme immobilized 3D-GO/PVA/Fe3O4 nanocomposites reached up to 90% of their activities. After 10 cycles of reuse, the activity of immobilized enzyme remained about 70.8% of the initial activity. The stability test revealed that the activity of immobilized enzyme remained up to 71.1% at 4 °C for 56 days.

Titania (TiO2) nanoparticles were added to polydimethylsiloxane (PDMS) matrix to form nanocomposite coating via spin coating method on the AA 2024 (one of the aluminum alloys) to improve the anticorrosion ability of metal. The microstructures of the PDMS/TiO2 composite coating were detected by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometry to verify the structure of composite coating. The corrosion properties of PDMS/TiO2 composite coating was evaluated by the electrochemical tests. The results showed that the anticorrosion ability of the composite coating has been significantly affected by the TiO2 content. For example, the impedance modulus value reached 106 Ωcm2 of the composite coating with 8 wt % nano-TiO2 fillers. Meanwhile, the corrosion current density (Icorr) of the coating was smaller than that of bare aluminum. The long term immersion experiments of coating were performed and the results demonstrated that the coating still had a protective effect on aluminum after 40 days of immersion.

Nickel selenide (NiSe) nanoparticles uniformly supported on graphene nanosheets (G) to form NiSe-G nanohybrids were prepared by an in situ hydrothermal process. The uniform distribution of NiSe on graphene bestowed the NiSe-G nanohybrid with faster charge transport and diffusion along with abundant accessible electrochemical active sites. The synergistic effect between NiSe nanoparticles and graphene nanosheets for supercapacitor applications was systematically investigated for the first time. The freestanding NiSe-G nanohybrid electrode exhibited better electrochemical performance with a high specific capacitance of 1280 F g-1 at a current density of 1 A g-1 and a capacitance retention of 98% after 2500 cycles relative to that of NiSe nanoparticles. Furthermore, an asymmetric supercapacitor device assembled using the NiSe-G nanohybrid as the positive electrode, activated carbon as the negative electrode and an electrospun PVdF membrane containing 6 M KOH as both the separator and the electrolyte delivered a high energy density of 50.1 W h kg-1 and a power density of 816 W kg-1 at an extended operating voltage of 1.6 V. Thus, the NiSe-G nanohybrid can be used as a potential electrode material for high-performance supercapacitors.

A core-shell structured zero-valent iron@carbon (ZVI@C) nanocompoiste was designed to improve the electron utilization of ZVI in the Cr(VI) reduction. The porosity of carbon layer in ZVI@C was optimized for improving the efficiency of electron utilization of ZVI in the Cr(VI) reduction process. The porous structure of carbon layer was controllably synthesized by adjusting the carbon source and the ratio of C/Fe in the precursor. The glucose was suggested as the optimal carbon source, and a high specific surface area (37.067 m2/g) was reached for the prepared ZVI@C when the ratio of C/Fe was controlled at 20. These ZVI@C performed well on Cr(VI) reduction, e.g. a complete reduction of Cr(VI) (2 mg/L) to Cr(III) within 10 min. The removal capacity (800 mg/g) exceeded previously recorded ZVI based adsorbents. The pH and initial Cr(VI) concentration were demonstrated as the key factors for the efficient electron utilization of ZVI. Furthermore, the efficiency of electron utilization of the ZVI increased up to 80% when the concentration of Cr(VI) was 2000 mg/L and the pH was controlled at 3, which was much higher than 8% of the naked ZVI.

To improve the resistance to hydrogen embrittlement and hydrogen permeation performance of vanadium (V) membranes, first-principles calculations were employed to study the stability, dissolution, and diffusion properties of H in transition metal (M = Mo, W)-doped V membranes, as well as their mechanical and thermodynamic properties, as alternative candidates for H2 separation. Our results revealed that the doping percentage of Mo/W alloying can significantly improve the mechanical and thermodynamic properties of pure V. The most stable location for adsorbed H atoms is the tetrahedral interstitial site (TIS) in the body-centered cubic structure of the V1-xMx (x = 0.0625, 0.125, 0.1875, and 0.25) alloys. Additionally, the hydrogen migration path should preferentially follow TIS → nearest-neighbor TIS. An M content of 0.25 yields the best anti-hydrogen embrittlement and the highest hydrogen-diffusion properties. The addition of individual Mo or W as doping elements into the V-based system greatly enhanced the hydrogen diffusion coefficient, and the addition of both Mo and W significantly improved the anti-hydrogen embrittlement of V-based alloys. Our results also showed that hydrogen concentration markedly influenced the solubility and diffusivity of hydrogen in V-based alloy membranes. These results provide a basis for the design of V-based alloy hydrogen permeation membranes.

Silicon nanocomposites have great potential applications in lithium-ion batteries. However, huge mechanical strain, capacity retention and unstable solid electrolyte interface formation weaken their applications in the real world. To overcome the above challenges, a novel facile route was adopted to design nanostructured silicon core carbon shell composites (Si@C), where the carbonization of phenolic resins led to a uniform porous thin interfacial layer of carbon. The phenolic resin precursor endowed mesoporous morphology with the carbon layer due to the carbonization of aromatic carbon, methylene linkages and hydroxyl groups. The mesoporous conductive carbon helped effectively to control the mechanical strain of silicon nanoparticles which maintained the integrity of Si@C nanocomposites and provided effective channels to easy access of electrolyte and short lithium ions transport. This novel Si@C anode offered a stable specific capacity of ∼868 mAh g−1 at 0.1 Ag-1 up to 500 cycles with ≥99% columbic efficiency.

Multi-walled carbon nanotubes (MWCNTs)/waterborne acrylic resin nanocomposite coatings were synthesized by a solution mixing method using 3-aminopropyltriethoxysilane (KH-550) coupling agent as the curing agent. The improvements on thermostability, conductibility, mechanical performances, and hydrophobicity of the as-prepared composite coatings were evaluated. The conductivity was improved by six orders of magnitude compared to pure waterborne acrylic resin. CNTs greatly enhanced the thermostability and reduced the curing temperature. The tensile test showed that the introduction of CNTs significantly enhanced the mechanical performances of the resin. The sample with 5 wt% CNTs exhibited the largest tensile strength, which was higher than pure resin. Moreover, the coating had an improved surface hydrophobicity. 6 wt% CNTs increased the contact angle of the coating from 81.32° to about 90°.

The oceans contain 4.5 billion tons of uranium which can supply almost infinite nuclear energy. However, it is an urgent need to develop adsorbents simultaneously possessing enhanced efficiency, collect ability, durability and economy to massively extract uranium from seawater. Herein, a simple two-step process is designed to massively produce pure poly(amidoxime) porous network membranes (PAO PNMs) which exhibit high uranium uptake capacity and excellent mechanical strength. The resulting membranes display high hydrophilicity, flexibility, strength (16.98 MPa tensile strength), stiffness (0.55 GPa Young's modulus), and porosity (3D porous network structure) which arise from a modified phase separation technique, providing the membranes a very high adsorption efficiency of 707 ± 5.8 mg-U/g-Ads in 8 ppm uranium spiked seawater and 9.35 ± 0.47 mg-U/g-Ads in natural seawater, respectively. Furthermore, the membranes exhibit a long service life of over 10 cycles of adsorption-desorption, and they can be massively produced via this facile phase separation technique by being simply immersed in water. Overall, coupled with the techno-economic advantages, these PAO PNMs are promising in industrial uranium extraction from seawater due to their robustness, high-efficiency and low-consumption.

The ZnIn-layered double hydroxides (ZnIn-LDHs) were synthesized by microwave hydrothermal method and used as the precursors to prepare the ZnIn-layered double oxides (ZnIn-LDOs) by the controllable calcination. The ZnIn-LDOs were aggregated by porous sheet materials, and the particle size was about 50 nm. The photocatalytic studies showed that the optimum molar ratio of Zn2+/ In3+ was 3:1 and the optimum calcination temperature was 600 °C. The photocatalytic degradation of MB by the as-prepared ZnIn-LDOs photocatalysts reached an efficiency of 98 % after irradiation under the simulated sunlight for 120 min. Radial trapping experimental results indicated that the main reactive specie for MB removal in the degradation processes was h+.

Lead telluride (PbTe) is an excellent thermoelectric material in the intermediate temperature zone and has been applied to deep space exploration, waste heat recovery and other fields. However, the low thermoelectric conversion efficiency of the n-type PbTe alloys limits its applications. Here, the thermoelectric performances have been enhanced in n-type PbTe alloys through trace bismuth (Bi) and iodine (I) co-doping. The Pb1-xBixTe1-xIx (x = 0.00%, 0.05%, 0.10%, 0.20% and 0.50%) alloys are synthesized in the single phase compounds by a stepwise synthesis method. The carrier concentration has reached an optimal concentration range within the order of 1019 cm-3. The highest absolute Seebeck coefficient of 244 μV/K is obtained for 0.05% doped alloy at 730 K. The highest absolute Seebeck coefficient leads to high power factor for 0.05% doped, especially in low- and middle-temperature range. The highest power factor ~ 25 μW/K2cm has been obtained at 329 K. Complex micro-scale grain boundaries and point defects strongly increase the phonon scattering and then lead to the lowest lattice thermal conductivity of 0.64 W/mK at 674 K for x = 0.50%, which is 26% lower than that of pristine PbTe. As a result, the highest figure of merit, zT ~ 0.9 has been determined in 0.20% doped samples at 725 K. Moreover, the highest average figure of merit, zTave ~ 0.7 has been achieved in 0.05% doped samples in the 323 - 723 K temperature range, which is about two or three times higher than reported for single Bi or I doped PbTe samples.

Porous hierarchical activated carbons (HACs) exhibit fascinating physical properties and are promising for supercapacitor applications. Facile and universal methods are required to produce high performance HACs on a large scale to boost their practical applications. An economical and template free method has been used to prepare HACs from lignocellulosic agricultural wastes with different contents of cellulose. These amorphous HACs exhibit high conductivity, a large specific surface area, and promising potentials for high performance supercapacitors. This study suggests the feasibility for facile and scalable conversion of inexpensive and earth-abundant agricultural wastes into high value-added carbon materials for energy storage applications.

The effects of chlorinated polyethylene (CPE) and antimony trioxide (Sb2O3) on the flame retardancy and mechanical properties of the recycled polyvinyl chloride/acryl-butadiene-styrene (R–PVC/ABS) blends were investigated. The tensile strength of the blends with 40 wt% ABS, 35 wt% R–PVC and 25 wt% PVC was close to that of ABS. Both the limiting oxygen index and the vertical burning level were significantly improved, and the blends reached a flame retardant level. The notched impact strength was significantly improved with the addition of CPE. The SEM observed interpenetrating CPE network structure in the blends resulted in a significant ductile fracture of the blends. With the addition of Sb2O3, the limiting oxygen index and vertical burning grade of the blends were further improved; and the heat release rate, total heat of release and mass loss were significantly reduced. When the addition amount of CPE and Sb2O3 was 8 wt% and 6 wt% respectively, the tensile strength of the blends was 63.5 MPa, the notched impact strength was 9.2 kJ m−2, the limiting oxygen index was 31.3%, and the vertical burning grade reached V0 level. This study provides a way to reuse the polyvinyl chloride with enhanced properties.

Antifouling biocides releasing restricts the longevity of antifouling coatings. Compared with the anchoring state, the releasing behavior of agents is much faster on the voyage, while the biofouling process is tougher. In this work, a series of capsaicin-based pH-triggered polyethylene glycol/capsaicin@chitosan (PEG/CAP@CS), polyvinyl alcohol (PVA)/CAP@CS and alginate (ALG)/CAP@CS multilayer films are prepared with controlling antimicrobial properties in marine environments. There are 23.70, 23.35 and 22.06 ppb CAP releasing from (PVA/CAP@CS)20, (PEG/CAP@CS)20 and (ALG/CAP@CS)20 films after immersing in pH 4 solutions for 60 days, while only 13.07, 12.95 and 11.55 ppb CAP have been found in alkaline solutions after immersing for the same time, respectively. All these three types of films exhibit extraordinary pH responsive properties. They can control the CAP release at a low level in alkaline solutions, and make the CAP release fast in acid solutions. Moreover, the antibacterial properties against P.aeruginosa are outstanding about 95.84%, 95.0% and 96.91% for (PVA/CAP@CS)20, (PEG/CAP@CS)20 and (ALG/CAP@CS)20 films, respectively. The bacteriostasis of (ALG/CAP@CS)20 film keeps 92.73% after 60 days in alkaline solution, which means it is steadily controlled in the marine environment. Although with similar antibacterial properties to those of (PEG/CAP@CS)20 film, (PVA/CAP@CS)20 film displays the maximum decrease with about 92% in acid solution after 60 days. The ALG/CAP@CS film with the best-controlled release performance and long-term antibacterial properties provides novel guidance for developing new antifouling coatings application in the marine environment.

Isolation of earth abundant biopolymer, Lignin, from Dendrocalamus sinicus and their structural properties were investigated to achieve its large-scale practical applications in value-added products. Two lignin fractions (MWL, DSL) were isolated with successive treatments of dioxane and dimethylsulfoxide (DMSO) from dewaxed and ball milled bamboo (D. sinicus) sample. The two-step treatments yielded 52.1% lignin based on the total lignin content in the dewaxed bamboo sample. Spectroscopy analyses indicated that the isolated bamboo lignin was a typical grass lignin, consisting of p-hydroxyphenyl, guaiacyl, and syringyl units. The major interunit linkages presented in the obtained bamboo lignin were β-O-4' aryl ether linkages, together with lower amounts of β-β', β-5', and β-1' linkages. The tricin was detected to be linked to lignin polymer through the β-O-4' linkage in the bamboo. In addition, phenyl glycoside and benzyl ether lignin-carbohydrate complexes (LCC) linkages were clearly detected in bamboo (D. sinicus), whereas the γ-ester LCC linkages were ambiguous due to the overlapping NMR signals with other substructures. The detailed structural properties of the obtained lignin fraction together with the light-weight will benefit efficient utilization of natural polymers as a possibly large-scale bio-based precursor for making polymeric materials, biochemicals, functional carbon and biofuels, and multifunctional polymer nanocomposites.

A convergent strategy was developed for the stereoselective synthesis of four unusual N-acylated monosaccharides (5-8), which are fragments of lipooligosaccharide IV (LOS-IV) from Mycobacterium marinum. A critical substrate-controlled asymmetric cyclization of an amino acid derived oxazolidine provided a key lactam intermediate 11, which was successfully converted to targets 5-7. The key step in the synthesis of 8 was a one-pot cascade oxidation-cyclization-oxidation reaction of a Boc-protected amino alcohol, prepared from 3-butynol, which led to the formation of lactam 15. The five-membered ring lactam intermediates in these synthetic routes were sensitive to elimination side reactions, but careful manipulation of the reaction sequence allowed for the stereoselective synthesis of the targets. This work represents the first synthesis of these unusual motifs, which have been shown to be essential to the bioactivity of LOS-IV.

Herein, we report the preparation of polyaniline (PANI) crystalline nanostructures and their dependent negative permittivity. By controlling the types of doped acids and the doping levels, PANI nanostructures with different crystallinity degrees are synthesized and composed of alternating metallic islands and amorphous regions confirmed by high resolution transmission electron microscopy (HRTEM). It's found that 0.15 mol L−1 of p-toluenesulfonic acid (PTSA) as doped acid is the optimal concentration to achieve a proper molecular weight (226,904 g mol−1) and higher degree of crystallinity (33.4%) from X-ray diffraction (XRD) for PANI. With further increasing the concentration of PTSA to 0.30 mol L−1, the degree of crystallinity (37%) of PANI has little change, but its molecular weight is quickly decreased to 35,102 g mol−1. As a consequence, the electrical conductivity of PANI increases from 1.1 × 10−3 S cm−1 for poly (2-acrylamido-2-methyl-1-propanesulfonic acid) (p-AMPS) to 6.9 S cm−1 for PTSA and the PANI crystalline nanostructures doped with PTSA and hydrochloric acid possess a negative permittivity within the measured frequency range of 20 Hz to 2 MHz, whereas the permittivity for PANI doped with perchloric acid, phosphoric acid, camphorsulfonic acid, and p-AMPS switches from negative at low frequency to positive at high frequency. By calculation from AC conductivity, the charge carrier transport in these PANI systems follows the polaron hopping transport mechanism.

Multi-dimensional (MD) structures comprised of one-dimensional (1D) conductive building blocks are one of key components to develop micro-/nano-sized electronics, sensors, and energy storage devices. Some progresses have been made to fabricate polyaniline (PANI) dendritic or branch-like structures in the solid-state chemical process or by the use of organic acids or surfactant gel at low temperatures. Nevertheless, it remains a difficult challenge for obtaining PANI dendrites with solid form, regular morphology, and high aspect ratio branches. With sodium lauryl sulfonate (SLS) as the soft template, PANI dendrites were readily synthesized in an undisturbed and low acid environment. The effects of hydrochloric acid concentration and SLS dosage on the resulting PANI structures were carefully investigated. Particular mechanistic researches illuminate that the dendrites are prepared by the bottom-up hierarchical assembly behavior, in which 1D branches grow and aggregate into much more orderly architecture spontaneously. Electrochemical performances of the prepared PANI dendritic structures were carried out in a 1.0 M H2SO4 electrolyte. And the specific capacitance was 204 F g−1, when the current density was 0.50 A g−1. Employing PANI dendrites as an example, herein, the displayed method provides a discernment to a strategy of structure and performances for conducting polymers.

Graphene can form a liquid crystal phase due to its anisotropic flake characteristics, it shows great potential in the field of high dielectric composites. In this paper, the graphene oxide sheets are grafted onto copolymer to uniformly disperse and maintain the liquid crystal state in a non-polar solvent, then the modified graphene oxide liquid crystal is transferred to polydimethylsiloxane. Graphene/polydimethylsiloxane nanocomposites are obtained by high temperature reduction and curing reactions. When the filler content is 4 wt%, the permittivity increases by 800% compared to pure polydimethylsiloxane. Therefore, graphene liquid crystal can significantly improve the dielectric properties of the nanocomposites than ordinary graphene, which provides a new method for preparing high dielectric properties composites.