Preparation of Nickel Oxide-Loaded Hierarchical Porous Alumina Ceramic for Photocatalytic Degradation of Methylene Blue

To address the problem of dye wastewater pollution, hierarchical porous alumina ceramics (HPAC) were prepared as carriers in this study by using digital light processing (DLP) 3D printing combined with the freeze-drying method. The results showed that the hierarchical porous alumina ceramics with a porogenic agent content of 33 wt% exhibited the highest porosity of 34.20% ± 1.22% and a pore size of 2–5 nm. An efficient photocatalytic system was constructed by loading nickel oxide nanoparticles (n-NiO) via the sol-gel method. The prepared photocatalytic carriers and photocatalysts were characterized for structural and morphological analysis using X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, and energy-dispersive X-ray fluorescence spectroscopy (EDS). The results indicated that n-NiO/HPAC with 15.43% NiO loading achieved optimal performance in methylene blue (MB) degradation experiments, with the MB degradation rate reaching 94.51%. This study provides a theoretical basis and technical support for the practical application of porous-material-loaded n-NiO photocatalysts in dye wastewater treatment. Graphical abstract