Flower shaped zinc oxide (ZnO) microstructures have been synthesized via electrochemical method by electrolyzing an aqueous solution of sodium nitrate using sacrificial zinc anode and steel cathode. Investigation on the effect of current density showed that flower shaped structures were formed at lower current density, while irregular ZnO clusters were formed in addition to flowers at higher current densities. Well defined microflowers were formed in neutral and basic electrolyte solutions than in acidic solution. The FESEM results revealed that the flower shaped microstructures have a diameter of similar to 2-3 mu m and possess several fusi form petals of similar to 1-2 mu m length. Photocatalytic behavior of the synthesized product was investigated through Levafix Blue CA (LB) dye degradation under UV light. The effect of operating parameters like the catalyst load and the initial dye concentration on the rate of dye degradation was studied. Nearly 100% decolorization and similar to 95% Chemical Oxygen Demand (COD) removal were achieved under optimum experimental conditions, which suggest potential photocatalytic behavior of the synthesized ZnO. (c) 2012 Elsevier B.V. All rights reserved.