PREPARATION AND CHARACTERIZATION OF Cu-Fe/TiO2 PHOTOCATALYST FOR VISIBLE LIGHT DEEP DESULFURIZATION

Abstract

A photooxidative system for deep desulfurization of model diesel fuel was explored. Nanoparticles of anatase titania (TiO 2 ) were synthesized via sol-gel hydrothermal method. The TiO 2 was further modified with bimetallic Cu-Fe using wet-impregnation method followed by calcination process in order to extend the activity region of the photocatalyst to visible-light. A series of bimetallic 2.2 wt% Cu-Fe/TiO 2 photocatalysts with different Cu:Fe mass compositions were characterized for their physical, chemical and optical properties using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), diffuse reflectance UV-visible spectroscopy (DR-UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) surface area analysis. The performance of the photocatalysts was evaluated for photooxidation of dibenzothiophene (DBT) as the sulfur species from model oil in the presence of hydrogen peroxide, H 2 O 2 under 500 W visible light illumination. The highest sulfur conversion of 82.36 % was observed for photocatalyst with 10:1 Cu:Fe mass composition.Keywords: photocatalyst, titania, oxidation, desulfurization, visible light, copper-iron Abstrak Sistem fotopengoksidaan untuk proses nyahsulfur daripada model minyak diesel dikaji. Nanopartikel titania (TiO 2 ) dengan fasa anatas disediakan menggunakan kaedah hidrotermal sol-gel. Pengubahsuaian dengan dwilogam Cu-Fe dilakukan terhadap TiO 2 menggunakan kaedah impregnasi basah diikuti dengan proses pengkalsinan untuk melanjutkan aktiviti fotokatalis ke bahagian cahaya tampak. Siri fotokatalis dwilogam 2.2 wt% Cu-Fe/TiO 2 dengan komposisi jisim Cu:Fe yang berlainan dicirikan untuk menentukan sifat-sifat fizikal, kimia dan optik menggunakan pembelauan sinar-X (XRD), pemancaran medan mikroskopi imbasan elektron (FESEM), mikroskopi transmisi elecktron beresolusi tinggi (HRTEM), spektroskopi pantulan resapan ultraungu-tampak (DR-UV-Vis), spektroskopi transformasi Fourier inframerah (FTIR) dan analisis luas permukaan BrunauerEmmett-Teller (BET). Kajian terhadap fotopengoksidaan dibenzothiophene (DBT) sebagai spesis sulfur di dalam model minyak menggunakan fotokatalis tersebut dilakukan dalam kehadiran hidrogen peroksida, H 2 O 2 di bawah sinaran cahaya tampak 500 W. Prestasi tertinggi penukaran sulfur yang tercapai adalah 82.36 %, daripada fotokatalis yang mempunyai komposisi jisim untuk Cu:Fe sebanyak 10:1.