Decorating Phosphorus Anode with SnO2 Nanoparticles To Enhance Polyphosphides Chemisorption for High-Performance Lithium-Ion Batteries.

Phosphorus has been regarded as one of the most promising next-generation lithium-ion battery anode materials, because of its high theoretical specific capacity and safe working potential. However, the shuttle effect and sluggish conversion kinetics hamper its practical application. To overcome these limitations, we decorated SnO2 nanoparticles at the surface of phosphorus using an electrostatic self-assembly method, in which SnO2 can participate in the discharge/charge reaction, and the Li2O formed can chemically adsorb and suppress the shuttle of soluble polyphosphides across the separator. Additionally, the Sn/Li-Sn alloy can enhance the electrical conductivity of the overall electrode. Meanwhile, the similar volume changes and simultaneous lithiation/delithiation process in phosphorus and SnO2/Sn are beneficial for avoiding additional particle damage near two-phase boundaries. Consequently, this hybrid anode exhibits a high reversible capacity of ∼1180.4 mAh g-1 after 120 cycles and superior high-rate performance with ∼78.5% capacity retention from 100 to 1000 mA g-1.

Progress of NiO-Based Anodes for High-Performance Li-Ion Batteries.

Rechargeable lithium-ion batteries (LIBs) are of great significance to the development of renewable energy. The traditional graphite anode is gradually unable to meet increasing demands for high energy density and power density due to its low theoretical capacity. NiO has gained considerable attention because of its high theoretical capacity, low toxicity, and stable chemical properties. This review summarizes the research progress of NiO-based nanomaterials in LIBs and centers on the electrochemical reaction mechanism, synthesis methods, and strategies for improving the electrochemical properties of NiO anodes. The results demonstrate that the electrochemical characteristics highly depend on the synthesis method, morphology, surface area, conductive substrate, etc. Compared with pure NiO, NiO-based composites including NiO/carbon-based materials and NiO/metal oxide often present higher capacity and cycle stability. Furthermore, challenges and future perspectives of NiO-based anodes are also discussed.

Biomolecule-assisted construction of cadmium sulfide hollow spheres with structure-dependent photocatalytic activity.

In this study, we report the synthesis of monodispersive solid and hollow CdS spheres with structure-dependent photocatalytic abilities for dye photodegradation. The monodispersive CdS nanospheres were constructed with the assistance of the soulcarboxymthyi chitosan biopolymer under hydrothermal conditions. The solid CdS spheres were corroded by ammonia to form hollow CdS nanospheres through a dissolution-reprecipitation mechanism. Their visible-light photocatalytic activities were investigated, and the results show that both the solid and the hollow CdS spheres have visible-light photocatalytic abilities for the photodegradation of dyes. The photocatalytic properties of the CdS spheres were demonstrated to be structure dependent. Although the nanoparticles comprising the hollow spheres have larger sizes than those comprising the solid spheres, the hollow CdS spheres have better photocatalytic performances than the solid CdS spheres, which can be attributed to the special hollow structure.

Controlled growth and applications of complex metal oxide ZnSn(OH)6 polyhedra.

We successfully controlled the crystallographic surface of ZnSn(OH)(6) crystals and systematically obtained ZnSn(OH)(6) crystals in different shapes including cubes, truncated cubes, cuboctahedrons, truncated octahedrons, and octahedrons using a simple solvothermal method in a methylcellulose (MC) ethanol/water solution. By simply adjusting the amount of the NaOH solution added to the reaction system, we observed the shape evolution of ZnSn(OH)(6) particles from cube to octahedron, with the sizes gradually increasing from about 200 nm to 1-2 µm. These results not only provide ZnSn(OH)(6) polyhedra bound by different lattice planes, but also make it possible to investigate the morphology-property relationship of ZnSn(OH)(6) particles with different morphologies obtained under similar conditions. The antibacterial activities of the as-prepared ZnSn(OH)(6) polyhedral particles were studied. It was found that the antibacterial activities of ZnSn(OH)(6) particles against Escherichia coli depend on the shape of the ZnSn(OH)(6) particles, demonstrating that the surface structure of nanocrystals affects the antibacterial activity. Additionally, the obtained ZnSn(OH)(6) polyhedra can be applied as precursors for Zn(2)SnO(4)/SnO(2) composites with different morphologies by calcining at 600 °C.

Two-dimensional activated carbon nanosheets for rapid removal of tetracycline via strong π-π electron donor receptor interactions.

Two-dimensional carbonaceous materials have sparked extensive attention in organic pollutants adsorption due to their unique structure to facilitate the formation of the physical or chemical bonding. Herein, natural two-dimensional porous activated carbon nanosheets with ultra-high specific surface area (2276.44 m2 g-1) are prepared by alkaline immersion-assisted circulating calcination techniques from corn straw piths. The prepared nanosheets exhibit rapid tetracycline adsorption capacity (633 mg g-1 within 5 min) and high equilibrium adsorption capacity of 804.5 mg g-1. Significantly, the nanosheets can adapt to a wide range of pH (at least between pH = 3-10) and are almost unaffected by coexisting ions. Mechanism studies and theoretical calculations demonstrate that the rapid and high-efficient adsorption of tetracycline mainly depends on the π-π electron donor receptor interactions. In addition, hydrogen bonding and pore filling was also responsible for tetracycline adsorption. This work provides important guidance for the development of the biobased high-performance adsorbents from agricultural waste.

Magnesium-regulated oxygen vacancies of cobalt-nickel layered double hydroxide nanosheets for ultrahigh performance asymmetric supercapacitors.

Rational design of layered double hydroxide (LDH) electrodes is of great significance for high-performance supercapacitors (SCs). Herein, ultrathin cobalt-nickel-magnesium layered double hydroxide (CoNiMg-LDH) nanosheets with plentiful oxygen vacancies are synthesized via sacrificial magnesium-based replacement reaction at room temperature. Self-doping and mild reduction of magnesium can significantly increase the concentration of oxygen vacancies in CoNiMg-LDH, which promotes the electrochemical charge transfer efficiency and enhances the adsorption ability of electrolytes. Density functional theory (DFT) calculations also indicate that Mg2+ doping can decrease the formation energy of oxygen vacancies in CoNiMg-LDH nanosheets, which increases the concentration of oxygen vacancies. Thus, the assembled asymmetric supercapacitor CoNiMg-LDH//Actived Carbon accomplishes a superior capacity of âˆ¼ 333 C g-1 (208 F g-1) at 1 A g-1 and presents a gravimetric energy density of 73.9 Wh kg-1 at 0.8 kW kg-1. It presents only 13% capacity loss at 20 A g-1 after 5000 cycles. This discovery emphasizes the positive role of magnesium in regulating oxygen vacancies to improve the performance of supercapacitors, which should be beneficial for extending the scope of superior SCs active materials.

An ultrasonic-assisted synthesis of rice-straw-based porous carbon with high performance symmetric supercapacitors.

Biomass porous carbon materials are ideal supercapacitor electrode materials due to their low price, rich source of raw materials and environmental friendliness. In this study, an ultrasonic-assisted method was applied to synthesize the rice-straw-based porous carbon (UPC). The obtained UPC exhibited a two-dimensional structure and high specific surface area. In addition, the electrochemical test results showed that the UPC with a 1 hour ultrasonic treatment and lower activation temperature of 600 °C (UPC-600) demonstrated optimal performance: high specific capacitances of 420 F g-1 at 1.0 A g-1 and 314 F g-1 at a high current of 10 A g-1. Significantly, the symmetric supercapacitors showed a high energy density of 11.1 W h kg-1 and power density of 500 W kg-1. After 10 000 cycles, 99.8% of the specific capacitance was retained at 20 A g-1. These results indicate that UPC-600 is a promising candidate for supercapacitor electrode materials.

Dichloridobis(phenyl 2-pyridyl ketone oxime)nickel(II) acetone solvate.

The Ni atom in the title compound, [NiCl(2)(C(12)H(10)N(2)O)(2)]·C(3)H(6)O, adopts a distorted octa-hedral geometry, being ligated by four N atoms from two different phenyl 2-pyridyl ketone oxime ligands and two Cl atoms. In the crystal structure, inter-molecular O-H⋯Cl hydrogen bonds link the mol-ecules into a chain structure along [010]. There is a π-π contact between the pyridine rings [centroid-centroid distance = 3.824 (5) Å].

α- and ß-Phase Ni-Mg Hydroxide for High Performance Hybrid Supercapacitors.

Mg-substituted α- and ß-phase nickel hydroxides with high specific capacitance and good stability have been synthesized via sacrificial metal-based replacement reaction. 2D α- and ß-phase nickel-magnesium hydroxide (NiMg-OH) have been synthesized by sacrificing magnesium (Mg) powder with nickel salt aqueous solutions. Interestingly, the phase of the obtained NiMg-OH can be controlled by adjusting the nickel precursor. As well, the Mg powder is used not only as Mg source but also alkali source to form NiMg-OH. The α-phase nickel-magnesium hydroxide sample (α-NiMg-OH) exhibits lager surface area of 290.88 m2 g-1. The electrochemical performances show that the α-NiMg-OH presented a superior specific capacitance of 2602 F g-1 (1 A g-1) and ß-phase nickel-magnesium hydroxide sample (ß-NiMg-OH) exhibits better stability with 87% retention after 1000 cycles at 10 A g-1. The hybrid supercapacitor composed of α-NiMg-OH and activated carbon (AC) display high storage performance and cycle stability, it presents 89.7 F g-1 (1 A g-1) and of 0-1.6 V potential window and it maintains capacitance retention of 84.6% subsequent to 4000 cycles.

A novel synthetic route to transition metal phosphide nanoparticles.

A novel synthetic route was developed to prepare nano-sized and well-dispersed phosphides of transition metals (Mo, Ni, and Co) from their corresponding oxide precursors. The current approach produced metal phosphides in dimethyl ether (DME) using the rapid heating reduction (RHR) method. The synthesis of phosphides in DME was interesting, since the composition of gas-phase products was predominantly H2, CO and CH4 with a minor amount of CO2 but without H2O. Based on XRD and MS results, the formation mechanism of the phosphides was proposed. The overall synthesis process cannot simply be regarded as the reduction of an oxide precursor and the decomposition of DME. The product distribution should be ascribed to a combination of other catalytic reactions. In addition, it is noteworthy that compared with the traditional method, viz. temperature-programmed reduction in H2 (TPR-H2), the present method used a higher heating rate to shorten the reaction time and can yield more finely dispersed metal phosphide nanoparticles. The good dispersion of phosphide nanoparticles is probably achieved due to the fact that no H2O was released in the RHR-DME process, which can avoid strong hydrothermal sintering.

Synthesis of attapulgite/N-isopropylacrylamide and its use in drug release.

Environmentally sensitive hydrogels as one of the most potential drug delivery systems have gained considerable interest in recent years. In the present study, we synthesized a newly temperature-responsive composite hydrogel based on attapulgite (ATP) and poly (N-isopropylacrylamide) (PNIPAM) as the localized drug carriers for drug delivery. The as-prepared ATP/PNIPAM hydrogel has large aperture which significantly improved the quantity of adsorption of drugs, exhibiting the excellent properties of drug release. The scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were used to characterize the ATP/PNIPAM. The swelling/deswelling behaviors and the release of ciprofloxacin lactate were studied. When the temperature was below the low critical solution temperature (LCST), the swelling property of hydrogels was excellent and the swelling rate was large. And, the drug release rate increased with the increase of the content of attapulgite in the composite hydrogel when it was put in the buffer solution (pH7.38) at 37.0°C. Therefore, the composite hydrogels might be very useful for its application in biomedical fields.

Synthesis and mechanism studies of novel drum-like Cd(OH)2 superstructures.

Novel drum-like Cd(OH)(2) superstructures with uniform size were synthesized on a large scale through a facile one-pot hydrothermal route with the co-existence of ammonia and biopolymer sodium carboxymethyl cellulose solutions.

Fabrication of novel comb-like Cu(2)O nanorod-based structures through an interface etching method and their application as ethanol sensors.

Novel comb-like cuprous oxide nanorod-based structures were synthesized through an interface etching method with salicylaldehyde as ligand and reducing agent in a water-toluene system and were demonstrated to have great application potentials as ethanol sensors.

One-step fabrication of Cd(OH)2 nanorings via a solution phase synthesis.

Cd(OH)(2) nanorings were synthesized in high yield via a one-step solution phase synthesis process at room temperature, in which the co-existence of ethanol and ammonia is the key factor for the formation of such a ring structure. Further calcination of the Cd(OH)(2) nanorings results in the formation of CdO nanorings.