Professor Lee In-su (CHEM) and his research team succeeded in making Janus Fe3O4 nanocube with a hole on one side by a very simple heat treatment method, and developing this particle into the swimmer, which can efficiently decompose the dyes in the water. This achievement attracted a lot of attention with a simple synthesis method, which is different from the former methods of partial etching and growth technique.

The team focused on the fact that iron ions move in response to high temperatures. They surrounded nanocubes with silica, and heat-treated them for iron ions to move to nearby silica’s shell and create holes. So far, there have been examples of making concave particles through synthesis or assembly, but no studies about creating holes have been reported.

Especially, the holes of nanocubes have a unique property, so crystals of platinum catalyst are created and can be synthesized as ‘Janus type particles’ with different shapes. Because these particles generate O2 bubbles in water, they are able to move in one direction by the bubble due to their asymmetric structure. Therefore, it is anticipated that Janus nanoparticles can be used as an efficient catalyst for the decomposition of pollutants.