Additive manufacturing of hollow connected networks for solar photo-Fenton-like catalysis.

A 3D-printing approach is used to fabricate green bodies/precursor microarchitectures that, upon annealing, allow the fabrication of hierarchical 3D hollow microarchitectures (3DHMs). The 3DHMs are composed mainly of TiO₂ and inorganic stabilizers that enable the production of inorganic cellular units upon thermal annealing at 650 °C. Morphological inspection reveals that the 3D architecture beams comprise TiO₂ nanoparticles (NPs). The inner and outer diameters of the hollow beams are ∼80 μm and ∼150 μm, retained throughout the 3D hollow network. A proof-of-concept photo-Fenton reaction is assessed. The 3DHMs are impregnated with α-Fe₂O₃ NPs to evaluate solar photo-Fenton degradation of organic compounds, such as MB used as control and acetaminophen, an organic pollutant. The optical, structural, and chemical environment characteristics, alongside scavenger analysis, generate insights into the proposed solar photo-Fenton degradation reaction over TiO₂ 3DHMs loaded with α-Fe₂O₃. Our work demonstrates newly hollow printed microarchitecture with interconnected networks, which can help direct catalytic reactions.