(Invited) TiO2 Single Nanotubes Decorated with Fe3O4 Nanoparticles for Photocatalytical Environmental Applications

Abstract

Self-organized TiO2 nanotubes arrays, formed by electrochemical anodization of Ti, have attracted tremendous scientific and technological attention, due to their remarkable properties such as the tunability of dimensions, their directionality, high surface area, high stability, and ability to absorb a significant amount of incident light [1,2].The most widely used electrolyte for the synthesis of TiO2 nanotube layers is based on ethylene glycol containing small amounts of water and fluoride ions. However, nanotubes prepared in these electrolytes present a double-walled structure. The outer wall consists of almost pure TiO2, and the inner wall consists of TiO2 contaminated with carbon and fluoride species [3,4]. In recent years, the selective etching of the inner nanotube wall on Ti layer enabled the synthesis of single-wall nanotubes that showed superior photo-electrochemical performance compared to their double-walled counterparts [5]. An extensive etching also enabled the synthesis of single-tube powders, which can be in turn effectively decorated with Fe3O4 nanoparticles to act as magnetically guidable photocatalysts [6,7].The presentation will discuss the synthesis of these nanotube morphologies and their performance in the photocatalytic degradation of model dye in the liquid phase as well as model drugs that are problematic in wastewaters. We will demonstrate how the photocatalytic performance is influenced by the single nanotubes and single nanotubes decorated with Fe3O4 magnetic particles. Experimental details and photocatalytic results will be presented and discussed.