Controlled synthesis of magnetic polyoxometalates/iron oxide composites for photocatalytic degradation

A series of Fe3O4/POMs composites have been successfully synthesized by the combination of Fe3O4 nanoparticles with various polyoxometalates (referred as "POMs" for short; POMs = α-PMo12, α-PW12, α-PW9, and α-SiW9). Detailed control experiments demonstrate that the morphology and size of the composites could be controlled by the type and amount of POMs, and all of these Fe3O4/PMo12 microflowers, Fe3O4/PW12 nanospheres, Fe3O4/PW9 microrods, and Fe3O4/SiW9 nanospheres show uniform morphology. Magnetic studies indicate that the Fe3+ ions in these composites display antiferromagnetic interactions. Furthermore, photocatalytic experiments indicate that Fe3O4/POMs composites exhibits catalytic activity for the photodegradation of RhB solution. Hence, these results not only enrich the diversity of POM-based materials, but also provide a new strategy to develop magnetic POMs catalysts.