Programme Book - UPM - Universiti Putra Malaysia

P21 PHOTOCATALYTIC DEGRADATION OF ORGANIC DYESBY TiO 2 PHOTOCATALYST IMMOBILISED ONTO ITO GLASSZ. Zainal 1,2,* , W.S. Hee 1 , N.A. Awaludin 1 , N.A.A. Rashid 11 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400UPM Serdang, Selangor, Malaysia2 Advanced Materials and Nanotechnology Laboratory, Institute of AdvancedTechnology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, MalaysiaCorresponding author: zulkar@science.upm.edu.myPhotocatalysis is a promising method in removing dyes from wastewater as thismethod is able to complete mineralization of the target pollutants, into non-toxicsubstances such as CO 2 , water and HCl if chlorinated contaminants are present. Underthe illumination of UV, TiO 2 coated onto glasses have self cleaning, disinfecting andanti-fogging properties. Thus, different techniques (dip coating, brush coating anddoctor blade) were applied to immobilise TiO 2 photocatalyst onto ITO glass in thisstudy. The tested organic dyes were Fast Green, Methylene Blue and Methyl Orangeusing TiO 2 slurry without and with HNO 3 treatment. Simple coating formulationinvolving commercialised TiO 2 powder (Degussa P25), polyethylene glycol (PEG),Triton X, ethanol and deionised water were used in the slurry preparation. Thin filmsamples of TiO 2 /ITO were calcined at 450 o C for 30 minutes. The obtained thin filmswere characterized using linear sweep photovoltammetry, ultraviolet-visiblespectroscopy, X-ray diffractometry, scanning electron microscopy and energydispersive X-ray spectroscopy. Effect of operating parameter towards thephotocatalytic degradation of organic dyes such as coating substrates, number ofcoating layers of TiO 2 onto ITO glass, concentration of TiO 2 , repeated usage ofTiO 2 /ITO thin films and initial concentration of organic dyes were investigated. Nitricacid treated TiO 2 displayed higher photocurrent response than untreated TiO 2 sample.Photocatalytic degradation of the tested organic dyes followed Langmuir–Hinshelwood first-order kinetics. Photocatalytic efficiency also varied with coatingtechniques used. It was found that after three hours of conducting the dye removalprocess, 10 ppm Fast Green was 8.206 ×10 -3 ppm min -1 cm -2 removed by using 15 g%of two dip coated layers of TiO 2 onto ITO glass. Besides, by using four layers of TiO 2brush coated thin film, 2.960 ×10 -3 ppm min -1 cm -2 of 10 ppm Methylene Blue wasremoved in four hours. For 10 ppm of Methyl Orange, it was 3.036 × 10 -3 ppm min -1cm -2 removed in four hours by using two doctor blade coated layers of 15 g % TiO 2 .36 |16 th Industrial Chemistry Seminar: Chemistry- A Passport to a Brighter Future