This paper reports photodegradation of Direct Blue 71 under irradiation by sunlight. We synthesized Fe:ZnO nanomaterials under mild hydrothermal conditions (P = autogenous, T = 100 °C, t = 18 h). The precursors were Fe(2)O(3) as dopant, n-butylamine as surface modifier, NaOH as mineralizer and reagent grade ZnO. The systematic experiments on the photodegradation of Direct Blue 71 were carried out by changing different effective parameters. The variables in this study were type of nanomaterials synthesized (4 types), nanomaterial dosage (0.4-1.0 g/L), contact time (30-120 min), pH (3-11), and dye concentration (20-100 ppm). The photodegradation efficiency was determined using a UV-Vis spectrophotometer. Determination of total organic carbon (TOC) amount was used to find out mineralization efficiency. Our experimental results revealed that the nanomaterials synthesized had higher efficiency compared with the reagent grade ZnO. The best efficiency was achieved at the following conditions: 1.0 g/L nanomaterials loading, 120 min contact time, pH 5, and photodegradation efficiency from more than 75 up to 99% depending upon the dye concentration.