The type of nanostructured materials depends on the precursor materials as well the synthesis process. Like nanorods rod zinc oxide, zinc acetate is preferable than chloride compound.
Especially by spray Pyrolysis technique we got better result. Aqueous soluble samples gives better result.
You have to choose a precursor which is a better electron scavenging agent and easily reducible means at low reduction potential. Further the kind of morphology you desire is governed by the optimization of the synthetic process parameters.