Kinetic Study of Organic Dye Degradation Using ZnO Particles with Different Morphologies as a Photocatalyst

Abstract

Zinc oxide (ZnO) particles were successfully synthesized via sol-gel approach using zinc acetate dihydrate (Zn(CH 3 COO) 2 ·2H 2 O) and ammonia (NH 4 OH) solution as precursors. By adjusting the reaction parameters such as amount of ammonia and reaction time as well as complexing agent aluminium sulphate Al 2 (SO 4 ) 3 , ZnO particles with different morphologies, that is, rodlike, ricelike and disklike could be synthesized. The effectiveness of ZnO particles with different morphologies (rodlike, ricelike and disklike) on the photocatalytic activity has been studied. The results showed that rodlike ZnO particles were the most effective in degrading the Rhodamine B (RhB) solution under the illumination of ultraviolet (UV) light. The rate constant was found to be first order, with rodlike particles the highest (0.06329 min −1 ), followed by rice-like ZnO particles (0.0431 min −1 ) and disk-like ZnO particles (0.02448 min −1 ).