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Formation of High Aspect Ratio TiO2 Nanotube Arrays by Anodization of Ti Foil in Organic Solution
(Penghasilan Susunan Nanotiub TiO2 Bernisbah Aspek Tinggi melalui Proses Penganodan Kerajang Ti dalam Larutan Organik)
Srimala Sreekantan*, Roshasnorlyza Hazan, Khairul Arifah Saharudin & Lai Chin Wei
School of Materials and Mineral Resources Engineering,
Engineering Campus
Universiti Sains Malaysia, 14300 Nibong Tebal, Seberang Prai Selatan, Pulau Pinang, Malaysia
Ishak Mat
Advanced Medical and Dental Institute, Kompleks EUREKA
Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia
Received: 7 July 2010 / Accepted: 3 September 2010
ABSTRACT
Titanium oxide (TiO2) nanotubes were successfully
formed by anodization of pure titanium foil in a
standard two-electrode bath consisting of ethylene glycol solution containing 5
wt% NH4F. The pH of the solution was ∼ 7 and the anodization voltage was 60 V. It was observed that such anodization condition results in ordered arrays of TiO2 nanotubes with smooth surface and a very high aspect
ratio. It was observed that a minimum of 1 wt % water addition was required to
form well ordered TiO2 nanotubes with length of approximately 18.5 μm. As-anodized
sample, the self-organized TiO2 nanotubes have amorphous structure and annealing at 500oC of the nanotubes promote
formation of anatase and rutile phase. Photocatalytic activity of well ordered TiO2 nanotubes with two different
lengths was evaluated by measuring the degradation of methyl orange (MO). The
elaboration of this observation is described in detail in this paper.
Keywords: Anodization; ethylene glycol; phase transformation; TiO2 nanotubes
ABSTRAK
Nanotiub titanium dioksida (TiO2) berjaya dihasilkan melalui penganodan kerajang titanium tulen dalam takungan 2-elektrod piawai dengan elekrolit larutan etilena glikol yang mengandungi 5% berat NH4F. pH larutan ialah ~ 7 dan voltan penganodan ialah 60 V. Didapati bahawa keadaan penganodan mempengaruhi susunan nanotiub TiO2, permukaan dinding lebih licin dengan nisbah aspek yang lebih tinggi. Didapati tambahan minimum 1% berat air diperlukan untuk menghasilkan nanotiub TiO2 yang tersusun dengan teratur dan panjang kira-kira 18.5 μm. Sampel yang dianod menghasilkan nanotiub TiO2 tersusun sendiri yang mengandungi struktur amorfus dan penyepuhlindapan nanotiub pada 500oC menggalakkan pembentukan fasa anatas dan rutil. Aktiviti foto-pemangkin bagi nanotiub TiO2 yang tersusun dengan panjang yang berbeza ditentukan dengan mengukur degradasi metil oren (MO). Penerangan lanjut mengenai pemerhatian ini diterangkan secara terperinci di dalam kertas ini.
Kata kunci: Etilena glikol; penganodan; nanotiub TiO2; transformasi fasa
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*Corresponding author; email: srimala@eng.usm.my
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