A ZnO film was electrodeposited onto a gold substrate obtained from a recordable compact disc and tested as photocatalyst in degradation of dye in aqueous solution. X-ray diffractometry and atomic force microscopic analysis showed a pure ZnO phase with particle sizes in the nanometric scale. The results showed that the photocatalytic activity of the film is significant, with more than 90 % degradation of the dye in under 6 h sunlight irradiation. The photocatalytic process in sunlight follows first-order kinetics.