CoFeub>2ub>/CoFeub>2ub>Oub>4ub>/MgO were built for expanding applications of magnetic particles.
Rattle-type photocatalysts were obtained in the absence of template and etchant.
The rattle-type particles exhibited the strong absorption to methylene blue.
The highest degradation efficiency reached 93% for CoFeub>2ub>/TiOub>2ub>.
CoFeub>2ub>/TiOub>2ub> can be easily separated due to its high magnetization.