“…Hierarchical porous alumina ceramics have attracted lots of attentions due to unique multifunctionality and mechanical efficiency for wide application in catalysts, filters, bioreactors, bone substitutes, thermal insulation materials, and so on . As is well-known, the performance of hierarchical porous ceramics is mainly determined by pore size, pore orientation, and open/closed porosity. − Some methods have been developed to control the preparation of hierarchical porous alumina ceramics, such as bulk casting with capillary suspensions, direct foaming, , emulsion, − and sacrificial template methods . However, these methods have difficulty in constructing complex three-dimensional (3D) shapes and precisely controlling the pore size or morphology due to time-consuming multistep processing.…”