Search

A visible light-driven AgBr/Ag 2 CO 3 nanosheets composite has been fabricated via a in-situ ultrasonic anion-exchange method at room temperature, using Na 2 CO 3 and cetyltrimethyl ammonium bromide (CTAB) as carbonate anion and bromide anion resources, respectively. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis demonstrated that the obtained products were consisted of AgBr nanoparticles and Ag 2 CO 3 nanosheets, in addition the AgBr nanoparticles were well distributed on the surface of sheet-like Ag 2 CO 3 to form AgBr/Ag 2 CO 3 heterostructure. Evaluation of the prepared AgBr/Ag 2 CO 3 hybrids photocatalytic activity by degradation of Rhodamine B (RhB) or Methyl orange (MO) under visible light irradiation (λ>420 nm) indicated they have efficient and higher photocatalytic activities compared to the pure AgBr and Ag 2 CO 3 samples, which could be related to the matched band potential band potential between AgBr and Ag 2 CO 3 . Besides, a possible photocatalytic mechanism of the hybrids was also proposed.

In this letter, graphene oxide (GO) was prepared by a kind of modified Hummers' method, which via ultrasonic treatment could be dispersed in water to obtain a homogeneous and stable brownish yellow flocculent solution. AgBr/Ag/Ag2O/GO nanocomposite catalyst was produced by adding hexadecyltrimethyl ammonium bromide (CTAB) and silver nitrate solution into the above formed GO solution under ultrasonic treatment. The structures, morphologies, and light absorption properties of AgBr/Ag/Ag2O/GO composite catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and ultraviolet and visible diffuse reflectance spectroscopy (UV-DRS). Preliminary results showed that the composite catalyst has a better catalytic degradation effect on organic dyes like rhodamine B (RhB) and methyl orange (MO) in polluted water under simulated solar light irradiation in contrast to the single GO and AgBr.

Hierarchically structured hollow microspheres composed of copper sulfide (CuS) nanoplatelets have been successfully fabricated via a one-pot and green sonochemical process for the first time, using copper acetate and thiourea aqueous solution as precursors without surfactant or template. Large-scaled hollow architectures with outer diameters in the range of 1–1.2 μm are assembled by pure hexagonal single crystalline CuS nanoplatelets, being of about 20 nm in thickness with stacking faults in the crystal lattice. The UV-Vis diffuse reflectance spectra (DRS) analysis suggests that the band gap energy of the as-obtained CuS sample was estimated to be 1.27 eV, showing a significant red-shift compared with the bulk value. Hollow CuS structures possess the high surface area and double pore size distributions as measured from the N2 adsorption isotherms. Moreover, the possible growth mechanism for CuS hollow spheres is proposed on the basis of the temporal evolution controlled experiments. More importantly, this hierarchically structured CuS catalyst show highly efficient Fenton-like catalytic activity in degrading highly concentrated dye-containing solution (50 mg·mL−1) with the help of hydrogen peroxide (H2O2), suggesting a promising application in wastewater purification.

AgBr/Ag3PO4 composite quasi-microcubes were fabricated by a simple ultrasonic synthesis method, in which hexadecyltrimethylammonium bromide was used as Br resource and surfactant. The structures and morphologies of the as-obtained product were initially characterised by X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray analysis spectroscopy. The ultraviolet–visible diffuse reflectance spectrum of the as-obtained products demonstrated that this hybrid structure exhibits an enhanced absorption ability in the visible region. Furthermore, the composite products exhibit much higher photocatalytic performance and stability on degradation of rhodamine B dye under the stimulated sunlight irradiation compared with pure AgBr and Ag3PO4.

Flammability performance and the microstructure of chars from poly(vinyl alcohol) (PVA) with α-type zirconium phosphate (α-ZrP) and montmorillonite (MMT) hybrid composites and multilayer composite were elucidated with microscale combustion calorimetry (MCC) and scanning electron microscopy (SEM). MCC revealed that the combination of α-ZrP and MMT did not impart synergistic effect in improving flame retardancy to PVA/ZrP/MMT hybrid composites, while multilayer composite showed better flame-resistant properties than hybrid composite. SEM demonstrated that the minimal loading levels of MMT in PVA/ZrP/MMT composites obstructed the development of intumescent chars in hybrid composites, but on-site mechanically reinforced the intumescent char in multilayer composite.

The mechanical properties and flame retardancy of linear low-density polyethylene/ethylene-propylene-diene terpolymer thermoplastic elastomers (TPEs) containing magnesium hydroxide sulfate hydrate (MHSH) whiskers and their corresponding un-vulcanized blends (UVBs) were evaluated using static tensile measurements, cone calorimetry and limiting oxygen index (LOI) tests. TPEs exhibited better fire-resistant properties in reducing peak heat release rate and improving LOI values to UVBs. Scanning electron microscopy (SEM) images showed that TPE sample left a more compact char after cone test. Results from tensile tests confirmed that TPEs had superior mechanical properties to UVBs due to the better compatibility between MHSH whiskers and polymer matrix.

The sol–gel method combined with electrospinning was used to synthesize polyvinylpyrrolidone nanofibers loaded with a mixture of Zn(Ac) 2 ·2H 2 O, Fe(NO 3 ) 3 ·9H 2 O and AgNO 3 , which generated mesoporous carbon fibers loaded with compounds including ZnFe 2 O 4 , Fe 3 O 4 and Ag after heat treatment at 850 °C in a N 2 atmosphere. Mesoporous carbon fibers loaded with ZnFe 2 O 4 –Fe 3 O 4 –Ag had a uniform pore size distribution, high specific surface area and strong ferromagnetism. They displayed high photocatalytic activity toward the degradation of methylene blue and methyl orange under visible light irradiation. This kind of complex magnetic semi-conductive mesoporous carbon fiber can be repeatedly used as a photocatalyst to dispose of organic wastewater. This simple synthesis method can be used to prepare other complex materials with multi-functional components.

A novel indexable TiC-based cermet tool (named tool A) with intra/intergranular microstructure has been designed and fabricated in application of face milling of a medium carbon steel (AISI 1045) in the dry condition comparison with commercial WC-Co tool (named tool B). Compared to the tool B, the newly as-prepared cermet tool A had an advantage of high speed cutting performances in cutting carton steel. Wear behavior was investigated in order to better understand the relationship between outstanding cutting properties and microstructure. The improved cutting performance of tool A can be attributed to the rim reinforced by TiN nanoparticles.

Beauty toothpaste, which can whiten teeth and refresh breath, is becoming more and more popular in the market. This paper studies the feasibility of applying zinc zeolite in toothpaste, including the preparation method of zinc zeolite toothpaste, quality index test, bacteriostasis test, stain removal test and halitosis reduction test. The results show that the quality of zinc zeolite toothpaste meets the requirements of china national standards. The bacteriostasis rate of 5% zinc zeolite toothpaste to Staphylococcus aureus and Escherichia coli can reach 99.9%. Zinc zeolite toothpaste has obvious effect of removing stains and halitosis. The conclusion of this paper is that zinc zeolite toothpaste is a safe and effective cosmetic toothpaste, which can be produced in batches.

This paper presents the results of a study in which nanosized titanium dioxide (TiO{sub 2}) crystal particles were coated onto the surface of palygorskite fibrous clay which had been modified by silver ions using titanium tetrachloride as a precursor. Coated TiO{sub 2} particles with the anatase structure were formed after calcining at 400 deg. C for 2 h in air. Various analytical techniques were used to characterize the surface properties of titanium dioxide particles on the palygorskite. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses showed that TiO{sub 2} particles were supported on the surface of the palygorskite clays and their size was in the range of 3-6 nm. The titanium oxide coatings were found to be very active for the photocatalytic decomposition of methylene blue.

Titanium dioxide coated on copper modified palygorskite clay nanocomposite (Cu 2+ -PG/TiO 2 ) prepared by hydrolysis method was used as photocatalyst in the degradation reaction of methylene blue. The surface characteristics of copper modified palygorskite coated with TiO 2 particles was confirmed by the X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), Brunauer–Emmett–Teller (BET) surface area analysis and X-ray photoelectron spectrometer (XPS). The incorporation of Cu 2+ did not change the structure of the palygorskite. The size of anatase particles was relatively small ( 2+ -PG/TiO 2 as high as 198.6 m 2 /g were measured for catalysts containing 0.6 wt.% copper and 25 wt.% titanium dioxide. The photocatalytic activity of those nanocomposite photocatalysts was much higher than that of the pure titanium dioxides.

Mingguang palygorskite clays, when modified with the silver and copper ion may be useful in removing bacteria from aqueous solution. The antibacterial effect of these modified clays were investigated using Escherichia coli and Staphylococcus aureus as indicators of fecal contamination of water. Introduction of Ag+ or Cu2+ did not change the crystal structure of the Mingguang palygorskite. It was found that the Mingguang silver and copper palygorskite minerals eliminated the pathogenic microorganisms E. coli and S. aureus from water with the average amount of silver and copper supported on the minerals after 12 h of contact time.

Porous magnetite (Fe 3 O 4 ) microspheres can be direct acquired by hydrothermal reaction of Fe-citrate complex (Fe (NH 4 ) 2 H (C 6 H 5 O 7 ) 2 ) in neutral solution. Results show that the obtained Fe 3 O 4 particles are nearly spherical in shape and about 2 μm to 3 μm in mean diameter. Every magnetite microsphere is made of many ultrafine Fe 3 O 4 nanoparticles and porous in structure. The as-prepared porous magnetite microspheres have higher surface area (~ 83 m 2 /g) and excellent magnetic properties (M s = 81 emu/g, H c = 145 Oe) at room temperature.

Porous hematite (α-Fe 2 O 3 ) nanomaterials can be simply acquired from amorphous iron (III) hydroxide (Fe (OH) 3 ) in neutral solution by an evaporation method in an open quartz flask in a vacuum drying oven. Results show that the as-obtained α-Fe 2 O 3 particles at 180°C for 2h or so are nearly spindle in shape. Each of α-Fe 2 O 3 microspindles is made of many ultrafine α-Fe 2 O 3 nanoparticles and results in a porous structure. The as-prepared porous α-Fe 2 O 3 powders have higher surface area (~78m 2 /g) and can rapidly remove Cr (VI) ions in wastewater at room temperature. The model of the adsorption kinetic of Cr (VI) is best adapted to the pseudo second-order equation. Keywords: Hematite, Thermal evaporation, Porous structure, Removal of Cr (VI) e-mail: hfuuhan@163.com 1. For Cr (VI) -adsorption: The aqueous solutions with constant Cr (VI) INTRODUCTION The design and synthesis of various morphologies nanostructures have been important research subjects in nanoscience and nanotechnology due to their unique size and shape-dependent chemical and physical properties. Nanosturctured hematite (α-Fe

Hierarchical hollow CuO submicrospheres have been fabricated on a large scale by a facile one-pot sonochemical process in the absence of surfactants and additives. The as-prepared products were investigated by XRD, FESEM, EDX, TEM, SAED, HRTEM and BET nitrogen adsorption–desorption isotherms. The results reveal that hollow pumpkin-shaped structures possess a monoclinic phase CuO with the diameters ranging from 400 to 500 nm, and their walls with around 45 nm in thickness are composed of numerous single crystalline CuO nanoribbons with a width of about 8 nm. The BET specific surface area of the as-synthesized CuO hollow structures was measured to be 59.60 m 2 /g, and the single point adsorption total pore volume was measured to be 0.1036 cm 3 /g. A possible growth mechanism for the formation of hierarchical hollow CuO structures was proposed, which is considered to be a sonohydrolysis – oriented aggregation – Ostwald ripening process. The novel hollow CuO spherical structures may utilize applications in biosensors, photonics, electronics, and catalysts.

Step-wise self-assembled flower-like δ-Bi2O3 microspheres from nanoparticles to nanosheets to microspheres were fabricated via a simple hydrothermal process, using glycine and Bi (NO3)3·5H2O as starting materials without other additives. The crystal structures and morphologies of the as-obtained samples were characterised by X-ray powder diffraction, field emission scanning electron microscope and transmission electron microscopy. The UV–vis diffuse reflectance spectrum of the sample showed the product has an intense absorption in UV light regions and an estimated bandgap 3.55 eV. Moreover, under UV-light irradiation the sample exhibited high photocatalytic behaviour for the degradation of rhodamine B dye and excellent stability, which possibly has a board application in wastewater disposal fields.