Synthesis of octahedral ZnO mesoscale superstructures via thermal decomposing octahedral zinc hydroxide precursors

A novel octahedral ZnO mesoscale superstructure (OZMS) was obtained by two steps: (i) Octahedral zinc hydroxide precursors (OZHP) with the sizes of 10–30 μm was first prepared using zinc acetate and ammonia as starting materials without any additives. (ii) Ligand and water molecules can be removed from the precursors during calcination and OZMS formed as a result. Controlling the morphology of the precursor is the key to obtain OZMS. The formation of the OZHP takes place in two stages: the first one is that the molecules in solution condense to crystalline nuclei, and the second is the growth of the nuclei. The morphology evolution of the ZnO products annealed at different temperatures is investigated. The stability of the OZMS depends on the electrostatic interactions among ZnO nanoparticles. The photo-luminescence (PL) measurements show that the OZMS has strong ultraviolet emission properties at 382 nm, and weak green light emission can also be detected, which is due to the defects that occurred in the formation process of OZMS.