Three-Dimensional Hierarchical Porous Structures of Metallic Glass/Copper Composite Catalysts by 3D Printing for Efficient Wastewater Treatments.

Finding highly efficient and reusable catalysts for advanced oxidation processes is a crucial endeavor to resolve the severe water pollution problems. Although numerous nanocatalysts have been developed in the past few decades, their recyclability along with sustainably high catalytic efficiency still remain challenging. Here, we propose a new strategy for designing efficient and reusable catalysts, that is, introducing Cu as a reductant into a metallic glass-based catalyst and constructing three-dimensional hierarchical porous architectures via a laser 3D printing technique. The as-printed 3D porous MG/Cu catalysts exhibit exceptional catalytic efficiency in degrading RhB with a normalized rate constant approximately 620 times higher than commercial nano zero-valent iron, outperforming most reported Fenton-type catalysts so far. Strikingly, the catalysts exhibit an excellent reusability and can be used more than 100 times (the highest record so far) without apparent efficiency decay. It is revealed that Cu-doping could improve the surface reducibility and promote the electronic transfer, rendering the 3D-printed MG/Cu catalysts with a sustainably active Fe(II)-rich surface and, therefore, unprecedented reusability. This work offers a broadly applicable design route for the development of advanced catalysts with an outstanding combination of activity and reusability for wastewater treatments.