Organic frameworks induce synthesis and growth mechanism of well-ordered dumbbell-shaped ZnO particles

Coordination bonds of ligands and metal ions are generally considered for improving agglomeration during the synthesis of metal oxides. However, the strong interactions always limit the performance due to the requirement of additional energy and calcination. A new strategy of synthesizing ZnO particles is proposed through a hydrothermal inducing redox method by using 2-methyl imidazole and Zn(NO3)(2). In situ direct redox between this organic ligand and NO3- in a hydrothermal condition is confirmed radical change instead of the simple coordination between organic ligands with Zn2+ in traditional method. The directly acquired ZnO particles possessing uniform dumbbell-like morphology have no obvious agglomeration. The yield reaches >95%. In particular, the synthesis mechanism and morphology evolution during the ZnO aggregates growth were carefully explored and proposed. Density functional theory (DFT) and surface energy calculations demonstrated the effects of activity variation of reactive groups and preferred growth surface of ZnO crystals. This work gives new insights into new synthesis strategy of ZnO particles via hydrothermal condition.