Hierarchically multifunctional K-OMS-2/TiO2/Fe3O4 heterojunctions for the photocatalytic oxidation of humic acid under solar light irradiation

► Hierarchical K-OMS-2/TiO2/Fe3O4 heterojunctions are synthesized for the first time. ► The synthesized material possesses excellent magnetic and photocatalytic properties. ► A proposed mechanism is used to illustrate the photocatalytic oxidation process.