title: Preparation and Photocatalytic Activity of Potassium- Incorporated Titanium Oxide Nanostructures Produced by the Wet Corrosion Process Using Various Titanium Alloys.
abstract: Nanostructured potassium-incorporated Ti-based oxides have attracted much attention because the incorporated potassium can influence their structural and physico-chemical properties. With the aim of tuning the structural and physical properties, we have demonstrated the wet corrosion process (WCP) as a simple method for nanostructure fabrication using various Ti-based materials, namely Ti-6Al-4V alloy (TAV), Ti-Ni (TN) alloy and pure Ti, which have 90%, 50% and 100% initial Ti content, respectively. We have systematically investigated the relationship between the Ti content in the initial metal and the precise condition of WCP to control the structural and physical properties of the resulting nanostructures. The WCP treatment involved various concentrations of KOH solutions. The precise conditions for producing K-incorporated nanostructured titanium oxide films (nTOFs) were strongly dependent on the Ti content of the initial metal. Ti and TAV yielded one-dimensional nanowires of K-incorporated nTOFs after treatment with 10 mol/L-KOH solution, whereas TN required a higher concentration (20 mol/L-KOH solution) to produce comparable nanostructures. The obtained nanostructures revealed a blue-shift in UV absorption spectra due to the quantum confinement effects. A significant enhancement of the photocatalytic activity was observed via the chromomeric change and the intermediate formation of methylene blue molecules under UV irradiation. This study demonstrates the WCP as a simple, versatile and scalable method for the production of nanostructured K-incorporated nTOFs to be used as high-performance photocatalysts for environmental and energy applications.
authors.affiliation: Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44-Bus 2450, Leuven B-3001, Belgium. soyoon.lee@mtm.kuleuven.be.
authors.forename: So Yoon
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Materials Engineering, the University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan. clee@us.ibm.com.
authors.forename: Choong Hyun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Laboratory of Photovoltaic Materials and Device, Department of Electrical Sustainable Energy, Delft University of Technology, Delft 2628CD, The Netherlands. d.kim@fz-juelich.de.
authors.forename: Do Yun
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Laboratory of Solid-State Physics and Magnetism, KU Leuven, Celestijnenlaan 200D, Leuven B-3001, Belgium. jeanpierre.locquet@fys.kuleuven.be.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Locquet
authors.affiliation: Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44-Bus 2450, Leuven B-3001, Belgium. maria.seo@mtm.kuleuven.be.
authors.forename: Jin Won
authors.initials: JW
authors.lastname: Seo
keywords: TiNi (TN); Ti–Al–V; nanostructures; photocatalysis; titanium; wet corrosion process  (WCP)