I am working on ZnO nanorods synthesis through hydrothermal method. I used Cr-Au coated glass substrate. I used equimolar solution of Zinc nitrate hexa hydrate and hexamethylene tetramine(C6H12N4) stirring continously for a night. My deposition time is 6 hour at 90C temperature. But i get the nano spheres rather then nanorods.Can any one please help me to guide the ZnO nanorods through this method.