Herbicides such as 2, 4-dichlorophenoxyacetic acid (2, 4-D) are generally carcinogenic and their existence in water cause many problems. In this work, Fe3O4/FexCuyWzOt core/shell magnetic photocatalyst was used to remove 2, 4-D. The statistical analysis of the results of the Box-Behnken experimental design method revealed that among the constituents of the photocatalyst shell, iron had the highest effect on 2, 4-D photodegradation. The photocatalyst composition was optimized using the response surface method. The photocatalyst formulation was determined using ICP method: Fe3O4/Fe0.874Cu0.349W0.004O1.525. XRD analysis confirmed the formation of Fe3O4, CuO, and WO3 in the photocatalyst shell. TEM images showed the photocatalyst core/shell structure. Fe3O4/Fe0.874Cu0.349W0.004O1.525 photodegraded 2, 4-D under ultraviolet light irradiation with the maximum yield of 90%. The photocatalyst was also active under sunlight and LED. The kinetics of the 2, 4-D photodegradation reaction under ultra violet light irradiation was studied. It followed first order kinetic model. The rate constant of the reaction was 0.0118 min-1. The photocatalyst activity of Fe3O4/Fe0.874Cu0.349W0.004O1.525 remained constant after the fourth cycle of reuse, which is the good advantage.
