Direct 3D Printing of Reactive Agitating Impellers for the Convenient Treatment of Various Pollutants in Water

Mass transfer plays a key role in the diffusion-controlled heterogeneous reactions. Varied efforts have been made to design the structure of catalysts and reactors to optimize the diffusion process. Herein, a facile strategy is reported to construct highly reactive agitating impeller (denoted as AI) by employing 3D printing and a facile surface activation treatment. On the one hand, experimental results and numerical simulation analysis reveal that the 3D printing AI with appropriate structure can not only effectively eliminate external diffusion but also conveniently be separated from heterogeneous reaction systems. On the other hand, surface activation helps to significantly promote the chemical reactivity of AI for Fenton and galvanic replacement reaction, which are used to treat organic and inorganic pollutants in water, respectively. Benefiting from these cooperative merits, the integrated catalytic AI delivers a catalytic performance toward Fenton reactions as high as a homogeneous catalyst, and the removal rate for heavy metal ions is nearly 100% through galvanic replacement. This 3D printing with surface engineering strategy should also be extended to other applications, and provide new field for preparing efficient and durable heterogeneous catalysts in a more economical way.