The Malaysian Journal of Analytical Sciences, Vol 14 No1 (2010): 41 - 49 41 EFFECT OF HTAB CONCENTRATION ON THE SYNTHESIS OF NANOSTRUCTURED TiO 2 TOWARDS ITS CATALYTIC ACTIVITIES (Kesan Kepekatan HTAB Terhadap Sintesis TiO 2 Nanostruktur Ke Atas Aktiviti Pemangkinannya) Ruslimie C. A, Mohd Hasmizam Razali* and Wan M. Khairul Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Terengganu, Malaysia *Corresponding author: mdhasmizam@umt.edu.my Abstract Titanium dioxide, TiO 2 photocatalyst was synthesised by microemulsion method under controlled hydrolysis of titanium butoxide, Ti(O(CH 2 ) 3 )CH 3 in Hexadecyl Trimethyl Ammonium Bromide, HTAB. The effect of various concentrations of surfactant in the range between 0.01-1.0 M were focused on by investigating their morphology, crystallite size, crystalline phase and specific surface area. After observation on their degradation performance, 0.5 M concentration of HTAB presented as a optimum concentration to synthesis TiO 2 photocatalyst. These results also supported by XRD spectra which are exhibited size of photocatalyst in the range within 50-150 nm. As a result, the catalytic properties of the synthesised TiO 2 nanostructure was performed by exhibiting good behaviour in photocatalytically degraded atrazine, 2-chloro-4-(ethylamino)- 6 (isopropylamino)-S-triazine to unharmful compounds in the environment. Keywords: TiO 2 , microemulsion, photodegradation, atrazine. Abstrak Fotopemangkin, titanium dioksida, TiO 2 telah disintesis melalui kaedah mikroemulsi di bawah kawalan hidrolisis titanium butoksida, Ti(O(CH 2 ) 3 )CH 3 di dalam Heksadesil Trimetil Ammonium Bromida, HTAB. Kesan kepelbagaian kepekatan surfaktan dalam julat 0.01-1.0 M telah difokuskan di dalam kajian terhadap morfologi, saiz hablur, fasa kehablurannya dan luas permukaan spesifik. Selepas pemerhatian dan perbandingan dijalankan terhadap prestasi degradasinya, kepekatan 0.5 M HTAB telah menunjukkan kepekatan optimum untuk mesintesis fotopemangkin TiO 2 . Keputusan ini juga telah disokong oleh spektra XRD yang mana telah mempamerkan saiz fotopemangkin adalah di dalam julat di antara 50-150 nm. Hasilnya, ciri- ciri mangkin TiO 2 nanostruktur yang telah disintesis menunjukkan sifat yang baik sebagai fotopemangkin bagi menguraikan atrazina, 2-kloro-4-(etilamino)-(isopropilamino)-S-triazina kepada sebatian-sebatian yang tidak berbahaya di dalam alam sekitar. Kata kunci: TiO 2 , mikroemulsi, fotopemangkinan, atrazina. Introduction Titanium dioxide, TiO 2 photocatalyst has attracted great attention as a promising photocatalyst for photocatalytically degrade organic pollutant in the environment [1]. TiO 2 nanostructure is considered to be one of the promising materials due to its ideal physical and chemical properties such as environmental friendly, low cost, high oxidizing ability, long term stability and also exhibit high photocatalystic activity [2, 3]. However, their physical, chemical and photocatalytic activities are known to depend on its preparation methods such as by changing their calcinations temperature, time aging and pH of solution which may give affect on its performance [4, 5]. There are numerous methods known to synthesise TiO 2 including microemulsion which is believed to be very promising method to obtain nanosized TiO 2 particle with less agglomeration and flocculation. In addition, the surfactant in microemulsion will act as stabilized micro cavities to provide a cage-like effect that limits particle nucleation, growth and agglomeration [6]. However, the optimum concentration of surfactant in the microemulsion has become an argument among researchers because apparently it depends on the type of surfactant and preparation method that are used during synthesis process. The main objective of the study is to investigate the effect of various surfactant concentrations in synthesise TiO 2 towards degradation performance. The optimal surfactant concentration will promise great properties of TiO 2 nanoparticles and may have better capacity to degrade 2-chloro-4-(ethylamino)-6 (isopropylamino)-S-triazine or widely known as atrazine to unharmful compounds in the environment.