%0 Journal Article
%T Kinetic Study of Organic Dye Degradation Using ZnO Particles with Different Morphologies as a Photocatalyst
%A Swee-Yong Pung
%A Wen-Pei Lee
%A Azizan Aziz
%J International Journal of Inorganic Chemistry
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/608183
%X Zinc oxide (ZnO) particles were successfully synthesized via sol-gel approach using zinc acetate dihydrate (Zn(CH3COO)2¡¤2H2O) and ammonia (NH4OH) solution as precursors. By adjusting the reaction parameters such as amount of ammonia and reaction time as well as complexing agent aluminium sulphate Al2(SO4)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). 1. Introduction Photocatalysis of organic compounds such as methyl green and Rhodamine B (RhB) in water is receiving attention due to the severe ecological impact of various industrial and agricultural pollutants [1, 2]. Photocatalytic activities can be classified into homogeneous or heterogeneous reactions depending on the nature of their reactants and materials (semiconductors). Particularly, heterogeneous photocatalytic study using semiconductor materials such as TiO2 and ZnO, through particulate systems, has become an exciting and rapidly growing area of research in the last few years mainly due to the relatively simple photodecomposition of organic pollutant molecules into less harmful compounds [3¨C7]. ZnO has been chosen as photocatalyst because of its high catalytic efficiency, low cost, large bandgap (3.37£¿eV), and nontoxic nature. In fact, it has been shown to be more effective than TiO2 as photocatalysts in recent studies [8, 9]. The effect of various parameters such as UV light intensity [3], initial dye concentration [3, 10, 11], pH of the medium [10], amount of photocatalyst [3, 11], doping [4, 12], and temperature [13] were reported. However, the effect of morphology of ZnO particles remains as a field to be explored. The morphology of ZnO particles can be easily manipulated by tailoring the reaction parameters. By adjusting the temperature, concentration of solution, pH, heating duration, and complexing agent, different morphology of ZnO particles such as nanoprisms [14], nanorods [15], nanoflowers [16], nanosheets [17], and nanodisks [18] could be synthesized, respectively. Different morphology of ZnO particles have different exposed
%U http://www.hindawi.com/journals/ijic/2012/608183/