Single and Mixed Phase TiO2 nanotubes by Electrochemical Anodization

Description

Titania (Titanium dioxide/TiO 2 ), is one of the most abundant elements and its application spans through various fields because of its chemical stability and specific photo induced properties. Utilization of TiO2 in applications such as water
splitting, solar cells, pollutant mineralization and disinfection needs high photocatalytic activity whereas in paints such as pigments and cosmetics as a UV absorbent controlled photo reactivity is needed. There are four polymorphs of titania found in nature Anatase, Brookite, Rutile and Monocilinic. Among these Rutile is the most thermodynamically stable and Anatase has the most favourable kinetics. In certain systems especially in
photocatalytic degradation reactions, the presence of two phases (biphasic) for example, Anatase and Rutile, results in visible light activation of the catalyst for the production of reactive hydroxyl radicals. Thus the crystalline nature of TiO2 in any
shape decides its fate of utilization. Precise and controlled fabrication of titania nanoforms, to avail its high surface area is a key challenge. One dimensional structure such as nanotubes and nanowires can be made as a mechanically stable three
dimensional assembly with high surface area. Annealing of amorphous nanotubes (up to 500°C) crystallized into Anatase phase, and heat treated beyond 500°C, resulted in Anatase to Rutile transformation along with collapsing of nanotube morphology.
In this work a simple and facile route to synthesise pure anatase and biphasic (Rutile+Anatase) nanotubes in powder form is proposed. This work focuses on nanotubes formation through rapid breakdown, electrochemical anodization with perchloric acid electrolyte and crystallization of the amorphous nanotubes through heat treatment. The
effect of impurities present in the system, which causes early nucleation favoring rutile phase growth by introducing surface defects and oxygen vacancies, was also investigated. This material showed promising photocatalytic degradation efficiency on Paracetamol and Famotidine (pharmaceutical compounds) in aqueous solutions.

Period	15 Jun 2015 → 17 Jun 2015
Event title	Nanotech France 2015 : The International Nanotech & NanoScience conference and exhibition
Event type	Conference
Location	Paris, FranceShow on map
Degree of Recognition	International