Influence of solvent molecular geometry on the growth of nanostructures.

Solvent properties such as surface tension, dielectric constant, and viscosity have been extensively studied over more than 150 years to understand their influence on the growth kinetics of nanostructures. Interestingly, these nanoparticles-based studies have missed the influence of solvent molecular geometry. Herein, by synthesizing ZnO nanorods on a highly conductive nitrogen incorporated graphene oxide (N-GO) substrate, we present the first study showing the influence of solvent molecular geometry on the growth mechanism of nanostructures. The solvents such as water (N-GO-ZnO-W) allow a large number of functional atoms along a, b and c-axis to coordinate in all possible directions with the metal ions of wurtzite hexagonal crystal system of ZnO and thus leads to lower aspect ratio nanorods. On the contrary, the unavailability of binding sites along a-axis for solvents such as ethanol (N-GO-ZnO-E) provides a size-limiting effect and leads to preferred growth along b and c-axis, thus generating ZnO nanorods with a higher aspect ratio. The study shows that the number of interacting atoms, carbon chain length and the solvent molecular geometry influence the aspect ratio and therefore a solvent could be used to tune the nanostructures morphology and hence the performance of devices based on them.