In Situ Anodization of WO3-Decorated TiO2 Nanotube Arrays for Efficient Mercury Removal

نویسندگان

  • Wai Hong Lee
  • Chin Wei Lai
  • Sharifah Bee Abd Hamid
چکیده

WO₃-decorated TiO₂ nanotube arrays were successfully synthesized using an in situ anodization method in ethylene glycol electrolyte with dissolved H₂O₂ and ammonium fluoride in amounts ranging from 0 to 0.5 wt %. Anodization was carried out at a voltage of 40 V for a duration of 60 min. By using the less stable tungsten as the cathode material instead of the conventionally used platinum electrode, tungsten will form dissolved ions (W6+) in the electrolyte which will then move toward the titanium foil and form a coherent deposit on the titanium foil. The fluoride ion content was controlled to determine the optimum chemical dissolution rate of TiO₂ during anodization to produce a uniform nanotubular structure of TiO₂ film. Nanotube arrays were then characterized using FESEM, EDAX, XRD, as well as Raman spectroscopy. Based on the FESEM images obtained, nanotube arrays with an average pore diameter of up to 65 nm and a length of 1.8 µm were produced. The tungsten element in the samples was confirmed by EDAX results which showed varying tungsten content from 0.22 to 2.30 at%. XRD and Raman results showed the anatase phase of TiO₂ after calcination at 400 °C for 4 h in air atmosphere. The mercury removal efficiency of the nanotube arrays was investigated by photoirradiating samples dipped in mercury chloride solution with TUV (Tube ultraviolet) 96W UV-B Germicidal light. The nanotubes with the highest aspect ratio (15.9) and geometric surface area factor (92.0) exhibited the best mercury removal performance due to a larger active surface area, which enables more Hg2+ to adsorb onto the catalyst surface to undergo reduction to Hg⁰. The incorporation of WO₃ species onto TiO₂ nanotubes also improved the mercury removal performance due to improved charge separation and decreased charge carrier recombination because of the charge transfer from the conduction band of TiO₂ to the conduction band of WO₃.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

One-Step Formation of WO3-Loaded TiO2 Nanotubes Composite Film for High Photocatalytic Performance

High aspect ratio of WO3-loaded TiO2 nanotube arrays have been successfully synthesized using the electrochemical anodization method in an ethylene glycol electrolyte containing 0.5 wt% ammonium fluoride in a range of applied voltage of 10–40 V for 30 min. The novelty of this research works in the one-step formation of WO3-loaded TiO2 nanotube arrays composite film by using tungsten as the cath...

متن کامل

High Efficient Transparent TiO2 Nanotube Dye-Sensitized Solar Cells: Adhesion of TiO2 Nanotube Membrane to FTO by Two Different Methods

In order to fabricate transparent TiO2 nanotube dye-sensitized solar cells, anodically growth nanotube membranes are detached from Ti substrate by a re-anodization method. The membranes are transferred on FTO glass by two different methods. At the first one, 100mM Ti-isopropoxide is used to make TiO2 nanoparticles for adhering TiO2 nanotube membranes to FTO and ...

متن کامل

Freestanding TiO2 Nanotube Arrays with Ultrahigh Aspect Ratio via Electrochemical Anodization

Self-organized, freestanding titania (TiO2) membrane with ultrahigh aspect ratio of the length/diameter (∼1500) was fabricated via electrochemical anodization of highly pure titanium (Ti) foil in fluorinecontaining ethylene glycol, followed by a simple and safe detachment of the formed TiO2 membrane from the metallic Ti substrate. The resulting membrane consists of highly ordered, vertically al...

متن کامل

Photo-electrocatalytic activity of TiO2 nanotubes prepared with two-step anodization and treated under UV light irradiation

To improve the photo-catalytic degradation of salicylic acid, we reported the fabrication of ordered TiO2 nanotube arrays by a simple and effective two-step anodization method and then these TiO2 nanotubes treated in a methanol solution under UV light irradiation. The TiO2 nanotubes prepared in the two-step anodization process showed better photo-catalytic activity than TiO2 nanotubes prepared ...

متن کامل

A high performance lithium-ion battery using LiNa0.02K0.01FePO4/C as cathode material and anatase TiO2 nanotube arrays as anode material

In this paper we report on a lithium ion battery (LIB) based on improved olivine lithium iron phosphate/carbon (LiFePO4/C) as cathode material and LiNa0.02K0.01FePO4/C  synthesized by sol-gel method and TiO2 nanotube arrays (TNAs) with an anatase phasesynthesized through anodization of Ti foil as an anode electrode. Crystallographic structure and surface morphology of the cathode and anode mate...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 8  شماره 

صفحات  -

تاریخ انتشار 2015