ABSTRACT
Eu2+-activated phosphors are widely applied in lighting and display areas because of their good optical performance. In this paper, an excellent green-emitting zeolite-3A: 1.3 wt% Eu phosphor is prepared by a green and eco-friendly high-thermal reaction method without any reducing atmosphere or agents. Meanwhile, the reducing mechanism from Eu3+ ions to Eu2+ ions is investigated. The experiment results show that the morphology, crystal structure, and luminescent property are affected by sintering temperature. The resulting sample shows the broad excitation band is in the range of 310-450 nm and the peak of the broad emission band is located at 523 nm. Furthermore, zeolite-3A: 1.3 wt% Eu phosphor is encapsulated on a commercial UV-emitting chip to fabricate a purity green light-emitting diode (LED) with the Commission Internationale de L'Eclairage (CIE) color coordinates at (0.295, 0.537).
ABSTRACT
The hollow polyaniline (PANI) micro/nanospheres are obtained through a simple monomer polymerization in alkaline solution with Triton X-100 Micelles as soft templates. The hollow PANI micro/nanospheres demonstrate rapid and effective removal ability for Chromium (VI) (Cr (VI)) in a wide pH range, and the maximum removal capacity can reach 127.88 mg/g at pH 3. After treated with acid, the used hollow PANI micro/nanospheres have about the similar removal capacity of Cr (VI) from wastewater.
ABSTRACT
One-dimensional noble-metal Ag nanoparticle chains have been prepared by electrodepositing Ag/Bi superlattice nanowires in a porous anodic alumina oxide (AAO) template and following an annealing process in vacuum. It is found that Bi, as a sacrificial metal, can be removed completely after annealing at 450 °C with a vacuum degree of 10(-5) Torr. The regulation of particle size, shape and interparticle spacing of Ag NP chains has been realized by adjusting the segment length of the Ag/Bi superlattice nanowires and the annealing condition. With an extension of the annealing time, it is observed that Ag particles display the transform trend from ellipsoid to sphere. Our findings could inspire further investigation on the design and fabrication of metal nanoparticle chains.
ABSTRACT
A facile and universal synthetic approach for preparing superlattice nanowire (SLNW) arrays is developed. In this method, two kinds of elements are alternately electrodeposited into the holes of the anodic alumina oxide (AAO) template, automatically in separate electrolytes by a programmed device. This method is not restricted by the relative values of the reduction potentials of the elements, and the deposition of each element can be controlled independently. Three kinds of representative SLNW arrays containing noble-metal material (Ag/Ni), thermoelectric material (Bi/Sb) and magnetic material (Ni/Cu) with adjustable segment length are fabricated successfully.
ABSTRACT
Titanium oxide-Ag composite (TOAC) adsorbents were prepared by a facile solution route with Ag nanoparticles being homogeneously dispersed on layered titanium oxide materials. The as-synthesized TOAC exhibited a remarkable capability for trace Cr(VI) removal from an aqueous solution, where the concentration of Cr(VI) could be decreased to a level below 0.05 mg/L within 1h. We have systematically investigated the factors that influenced the adsorption of Cr(VI), for example, the pH value of the solution, and the contact time of TOAC with Cr(VI). We found that the adsorption of Cr(VI) was strongly pH-dependent. The adsorption behavior of Cr(VI) onto TOAC fitted well the Langmuir isotherm and a maximum adsorption capacity of Cr(VI) as 25.7 mg/g was achieved. The adsorption process followed the pseudo-second-order kinetic model, which implied that the adsorption was composed of two steps: the adsorption of Cr(VI) ions onto TOAC followed by the reduction of Cr(VI) to Cr(III) by Ag nanoparticles. Our results revealed that TOAC with high capacity of Cr(VI) removal had promising potential for wastewater treatment.
Subject(s)
Chromium/isolation & purification , Silver/chemistry , Titanium/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Adsorption , Hydrogen-Ion Concentration , Kinetics , Metal Nanoparticles/chemistry , SolutionsABSTRACT
In this article, the porous-ZnO-nanobelt film was synthesized by oxidizing the ZnSe-nanobelt film in air. The experiment results show that the porous-ZnO-nanobelt film possesses enhanced photocatalytic activity compared with the ZnO-nanobelt film, and can be used as recyclable photocatalysts. The enhanced photocatalytic activity of the porous-ZnO-nanobelt film is attributed to the increased surface area. Therefore, turning the 1D-nanostructure film into porous one may be a feasible approach to meet the demand of photocatalyst application.
ABSTRACT
In this paper, ZnGa(2)O(4) hierarchical nanostructures with comb-like morphology are fabricated by a simple two-step chemical vapor deposition (CVD) method: first, the Ga(2)O(3) nanowires were synthesized and employed as templates for the growth of ZnGa(2)O(4) nanocombs; then, the as-prepared Ga(2)O(3) nanowires were reacted with ZnO vapor to form ZnGa(2)O(4) nanocombs. Before the reaction, the Au nanoparticles were deposited on the surfaces of Ga(2)O(3) nanowires and used as catalysts to control the teeth growth of ZnGa(2)O(4) nanocombs. The as-prepared ZnGa(2)O(4) nanocombs were highly crystallized with cubic spinel structure. From the photoluminescence (PL) spectrum, a broad band emission in the visible light region was observed of as-prepared ZnGa(2)O(4) nanocombs, which make it promising application as an optical material.
ABSTRACT
We have successfully prepared anodized alumina membrane distributed Bragg reflector (DBR) using electrochemical anodization method. The transmission peak of this distributed Bragg reflector could be easily and effectively modulated to cover almost any wavelength range of the whole visible spectrum by adjusting anodization temperature.
