Controllable growth of ZnO mesocrystals using a facile electrochemical approach

We developed an electrochemical approach for the synthesis of ZnO mesocrystals with controlled aspect ratios. The ZnO mesocrystals performed 3 stages including nucleation, growth and subsequently self-assembly into a 3D architecture during the growth process. A nonclassical mechanism ‘oriented attachment (OA)’ is responsible for the formation of wurtzite ZnO mesocrystals. Based on the understanding for the growth mechanism, various ZnO mesocrystals with different aspect ratios was synthesized by controlling the current density of deposition. Their cathodoluminescent (CL) spectra showed an enhanced increase with the decrease of aspect ratios (length to diameter). This Letter is potentially helpful for researchers to understand the aggregation-driven formation of complex high-order structured materials.