Sains Malaysiana 37(3):  271-275(2008)

Performance of Quartz Crystal Microbalance Gas Sensors Using

Thin Films of Titanium Dioxide, Porphyrin and Titanium

Dioxide Coated with Dye Porphyrin

(Prestasi Penderia Gas Mikroneraca Hablur Kuartza Menggunakan

Film Nipis Titanium Dioksida dengan Porfirin dan Titanium Dioksida

disalut dengan Pencelup Porfirin)

Syariena Arshad & M.M. Salleh

Institute of Microengineering and Nanoelectronics (IMEN)

Universiti Kebangsaan Malaysia, 43600 Bangi,

Selangor, Malaysia

M. Yahaya

School of Applied Physics

Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi,

Selangor, Malaysia

Received: 12 June 2007 / Accepted: 15 October 2007

ABSTRACT

Titanium dioxide (TiO₂), porphyrin and TiO₂ coated with dye porphyrin thin films were prepared on Quartz Crystal Microbalance (QCM) using sol-gel dip coating method and were tested for sensing of volatile organic compounds (VOCs). The porphyrin used was 5,10,15,20-tetraphenyl-21H,23H-porphine manganese (III) chloride (MnTPPCl). The sensing sensitivity was based on the change in the fundamental frequency of the QCM upon exposure towards six vapor samples, namely ethanol, acetone, cyclohexane, toluene, o-xylene and 2-propanol. It was found that all the thin films were sensitive towards all the vapors. However, the TiO₂ coated MnTPPCl thin film exhibit the most sensitive and has good selectivity property.

Keywords: Titanium dioxide (TiO₂); dye porphyrins; Quartz Crystal Microbalance; sol-gel dip coating method; volatile organic compounds (VOCs)

ABSTRAK

Filem nipis titanium dioksida (TiO₂), porfirin dan TiO₂ bersalut porfirin disediakan di atas mikroneraca hablur kuartza (QCM) menggunakan teknik swa-lekatan sol-gel dan diuji untuk pengesanan gas sebatian meruap. Porfirin yang digunakan adalah 5,10,15,20-tetrafenil-21H,23H-porfin mangan (III) klorida (MnTPPCl). Kepekaan pengesanan adalah berdasarkan perubahan pada frekuensi asal QCM apabila didedahkan kepada enam sampel sebatian organik meruap iaitu etanol, aseton, sikloheksana, toluena dan o-xilena. Didapati semua filem nipis peka terhadap semua gas. Filem nipis TiO₂ bersalut porfirin menunjukkan kepekaan tertinggi dan mempunyai sifat kebolehpilihan yang baik.

Kata kunci: Titanium dioksida (TiO₂); pencelup porfirin; mikroneraca hablur kuartza (QCM); kaedah salutan dalam sol-gel; sebatian organik meruap

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