Probing mechanisms of site-specific heterogeneous nucleation and directional nanobranch growth

by Zhang, Tierui Z.; Tian, Z. Ryan; Dong, Wenjun; Njabon, Roland N.; Anderson, Quincy; Varadan, Vijay K.

Understanding the heterogeneous nucleation and hierarchical nanocrystal growth mechanisms is important to the rational design and "bottom-up" grafting of hierarchically nanostructured materials. Most discussions in literatures on the mechanisms are normally based on thermodn. evidences that reveal little about stepwise details of both mechanisms. We here combine new kinetic data, including activation enthalpy and entropy, with spectroscopic results to uncover the multi-step details of the mechanisms, and the roles of org. structure directing agent and a mild heating in the hierarchical ZnO nanosyntheses. Thus-enriched interfacial knowledge may help solve the lattice mismatch and "mechanochem." problems in nanodevice fabrications from solns.