Synthesis of porous zinc-based/zinc oxide composites via sol–gel and ambient pressure drying routes

Porous Zn-based and ZnO composites are successfully fabricated via the sol–gel process and ambient pressure drying method using hexane as the drying solvent for the reduction in capillary force during drying process. Various highly porous Zn-based phases (Zn₁-based and Zn₅-based) that are studied by X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy show that they contribute through heat treatment (at 200 °C) to the development of ambient pressure dried nanoporous wurtzite (hexagonal) ZnO. A macroporous flower-like structure consisting of nanosheets is observed in porous Zn-based composites, and nanoporous structure is observed within platelets of ZnO nanoparticles. Possible routes for preparing highly porous Zn-based/ZnO composites are discovered by detailing the process for ambient pressure drying synthesis of porous wurzite ZnO.