PHOTOCATALYTIC STUDY OF WO3 PARTICLES IN REMOVAL OF ORGANIC DYE

Rabiatul AK, Pung SY* , Srimala S, Ong MT and Geetha S

Abstract

PHOTOCATALYTIC STUDY OF WO³ PARTICLES IN REMOVAL OF ORGANIC DYE

 Rabiatul AK¹, Pung SY^1[1], Srimala S¹, Ong MT² and Geetha S²

¹School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal 14300, Penang, Malaysia.

²Institute For Research In Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.

WO₃ particles were synthesized using sol-gel method. The WO₃ particles was prepared using 0.4 M of sodium tungstate dehydrate for 21 h at 90 ºC. The photocatalytic activity of WO₃ particles in removal of RhB dye followed first order kinetics in both visible light and UV light irradiation. The investigation showed that WO₃ particles degraded RhB dye more effectively under UV irradiation (43.2 %) than visible irradiation (2.6 %) in 75 min. The poor photodegradation efficiency was attributed to the narrow excitation band of visible light source. Besides, the scavenger tests indicated that the holes and hydroxyl radicals were the dominant reactive species in photocatalytic degradation of RhB dye. Based on these findings, the photodegradation mechanism of RhB dye by WO₃ particles is proposed.

Keywords: photocatalyst, semiconductor, sol-gel

[1] Corresponding author: Tel: +6 04 599 5215  

E-mail: sypung@usm.my