Photocatalytic degradation of phenol under solar radiation using microwave irradiated zinc oxide

The effect of preparation method on the photocatalytic degradation of phenol using zinc oxides under solar radiation was studied in batch reactors. Zinc oxide was prepared by different methods by varying precipitating agents and the source of precursors and microwave irradiation time and characterized by XRD, surface area, acid sites and crystallite sizes. The photocatalytic reactions were carried out by varying the reaction conditions such as preparation methods, microwave irradiation time, activation temperature, solar irradiation time, catalyst amount, substrate concentration etc. Under optimization conditions, it was found that 15 min microwave irradiated sample shows 88% phenol (0.6 g/l dose) degradation at pH 5.0 and 4 h reaction time under sunlight. Zinc oxide samples prepared by microwave irradiation and calcined at 573 K exhibit highest surface area, acid sites and lowest crystallite sizes and show highest activity towards photocatalytic oxidation of phenol. 2005 Elsevier Ltd. All rights reserved.