The invention relates to a method for preparing a TiO2 / PS / Fe3O4 magnetic
nanoparticle photocatalyst, comprising the following steps of: (1) preparing
oleic acid modified Fe3O4 nanoparticles; (2) preparing an aqueous-phase magnetic fluid; (3) preparing
styrene miniemulsion; (4) preparing magnetic
polystyrene beads PS / Fe3O; and (5) preparing the magnetic photocatalyst TiO2 / PS / Fe3O4, which specifically comprises the following steps of: mixing absolute ethyl
alcohol with
tetra-n-butyl
titanate, and performing magnetic stirring to form a solution A; adding the magnetic
polystyrene beads PS / Fe3O to de-ionized water and performing ultrasonic treatment to form a solution B; under magnetic stirring, adding the solution A to the solution B, thereby obtaining
sol after 30-40 min, wherein TiO2 covers the PS / Fe3O at the moment; after condensing and refluxing the
sol in a water bath, filtering the
sol to obtain the TiO2 / PS / Fe3O4, washing the TiO2 / PS / Fe3O4 by using
ethanol, filtering, washing by using
distilled water and filtering, thus obtaining a
solid; and
drying the
solid until the weight thereof is constant, thereby obtaining the magnetic photocatalyst TiO2 / PS / Fe3O4 with the
polystyrene PS as an isolating layer, the Fe3O4 as a
magnetic core and the TiO2 as a shell. The product obtained by using the method is low in
energy consumption, high in catalytic activity and recyclable.