Synthesis of Eu-Doped TiO2 Nanotubes Using Electrochemical Oxidation

2013 ◽  
Vol 543 ◽  
pp. 188-191 ◽  
Author(s):  
Han Jun Oh ◽  
Jong Ho Lee ◽  
Seung Hyun Lee ◽  
Choong Soo Chi

To improve the photocatalytic properties of titania photocatalyst by incorporated Eu element during electrochemical oxidation, Eu-doped titanium oxide nanotube was synthesized by anodic process in an ethylene glycol electrolyte with Eu (NO3)3 as an additive. The crystalline structure and surface characteristics of Eu-doped titania nanotube were investigated. The XPS results indicate the migration of the europium element into the titania nanotube layer from mixture electrolyte during electrochemical oxidation. The Eu-doped titania nanotubes show much higher activity of dye degradation.

2013 ◽  
Vol 651 ◽  
pp. 302-305
Author(s):  
Han Jun Oh

In order to improve the photocatalytic efficiency, the N doped anodic titania film for photocatalyst was synthesized by anodic oxidation of TiN layer in sulfuric electrolyte, and the photocatalytic properties of N doped TiO2layer were investigated. During the oxidation process of the TiN layer, nitrogen was doped into the anodic titania film due to the change of the titanium nitride layer to TiO2layer film. In the evaluation of dye degradation, N doped titania catalyst shows much higher efficiency than non-doped titania film.


2009 ◽  
Vol 255 (6) ◽  
pp. 3687-3690 ◽  
Author(s):  
M. Alam Khan ◽  
Do Hung Han ◽  
O.-Bong Yang

2020 ◽  
Vol 90 (5) ◽  
pp. 746
Author(s):  
С.К. Лазарук ◽  
О.В. Купреева ◽  
Д.А. Циркунов ◽  
Д.А. Сасинович ◽  
В.В. Дудич ◽  
...  

The conditions for the formation of anodic titanium oxide with a tubular structure were studied. The mechanism for the formation of tubular titanium oxide based on the localization of the electrochemical oxidation of titanium in the places of the barrier layer at the bottom of the pore, where the density of the flowing anodic current is increased, as a result of which the temperature of these regions increases. With an increase in the temperature of the barrier layer above the threshold value, a transition from the traditional «honeycomb-like» porous structure to the tubular structure takes place. The proposed mechanism is confirmed by the results of experimental research.


Author(s):  
Jorge Silva-Yumi ◽  
Telmo Moreno Romero ◽  
Gabriela Chango Lescano

Nanofluids constitute an alternative for the most efficient use of energy as they allow generating or improving thermal properties among others of traditional fluids, they are defined as so-called base fluids, such as: water, ethylene glycol, oils, etc., which contain nanoparticles in suspension , such as: aluminum oxide, silicon oxide, titanium oxide, metal nanoparticles, carbon nanotubes, graphene, carbides, etc. Nanofluids can be synthesized by two methods, the nanoparticles can be obtained separately and then the nanofluid is prepared or both nanoparticles and the nanofluid can be prepared simultaneously, an important factor to consider in obtaining nanofluids is their stability. Stability can be achieved by physical treatment or chemical treatment using surfactants. There are many studies about nanofluids, however, most are obtained with synthetic nanoparticles, leaving the use of natural nanoparticles as a field to be explored, as well as other surfactants to improve their stability. Keywords: nanofluids, hybrid nanofluids, nanoparticles, nano refrigerant. Resumen Los nanofluidos constituyen una alternativa para el uso más eficiente de energía pues permiten generar o mejorar las propiedades térmicas entre otras de los fluidos tradicionales, son definidos como fluidos denominados base, como: agua, etilenglicol, aceites, etc., que contienen nanopartículas en suspensión, como: óxido de aluminio, óxido de silicio, óxido de titanio, nanopartículas metálicas, nanotubos de carbono, grafeno, carburos, etc. Los nanofluidos se pueden sintetizar por dos métodos, se pueden obtener las nanopartículas por separado y luego preparar el nanofluido o se puede preparar simultáneamente las nanopartículas y el nanofluido, un factor importante a considerar en la obtención de nanofluidos es su estabilidad. La estabilidad se puede lograr mediante tratamiento físico o tratamiento químico mediante la utilización de surfactantes. Existen muchos estudios acerca de nanofluidos sin embargo, la mayoría se obtienen con nanopartículas sintéticas, quedando el uso de nanopartículas naturales como un campo por explorar al igual que otros surfactantes para mejorar su estabilidad. Palabras Clave: nanofluidos, nonofluidos híbridos, nanoparticulas, nanorefrigerantes.


2020 ◽  
Vol 10 (15) ◽  
pp. 5243
Author(s):  
Frederick Lia ◽  
Clayton Farrugia ◽  
Maria Antonietta Buccheri ◽  
Giancarlo Rappazzo ◽  
Edwin Zammit ◽  
...  

The application of titanium oxide nanotubes for the removal of contaminants from freshwater is a rapidly growing scientific interest, especially when it comes to water conservation strategies. In this study we employed four different titanium oxide nanotube surfaces, prepared by a two-electrode anodic oxidation. Two of the surfaces were synthesised in aqueous media, while the other two surfaces were synthesised in ethylene glycol. One of the arrays synthesised in the organic medium was impregnated with silver nanoparticles, while the remaining surfaces were not. The chemical reactivity of the various surfaces was assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as free electron sensitive probe molecules, in parallel with tannic acid degradation and copper ion reducing capacity. The potential antimicrobial activity of the surfaces was assessed against a panel of microorganisms composed of yeast, fungi, Gram-positive and Gram-negative bacteria. Field emission scanning electron microscopy revealed that surfaces produced in the aqueous medium had a smaller tube length and a smaller tube diameter. It was noted that one of the materials using sodium sulfate as the supporting electrolyte had the most irregular nanostructure morphology with tubes growing to the side rather than vertically. The structural variation of the surfaces directly reflected both the chemical and biological activity, with the nanotubes formed in ethylene glycol showing the fastest rates in the stabilization of DPPH and ABTS radicals, the fastest tannic acid decomposition under various pH conditions and the fastest metal reducing activity. Furthermore, the surface containing silver and its bare counterpart showed the most effective antimicrobial activity, removing approximately 82% of Gram-negative bacteria, 50% of Gram-positive bacteria, 70% of yeast and 40% of fungi, with Gram-negative bacteria being the most susceptible to these surfaces.


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