Kinetics of PbCrO4 Nanorod Growth by Oriented Attachment at the Air−Water Interface

Oriented attachment is a new way of crystal growth to transform preformed nanoparticles into hierarchical assemblies. Here, we demonstrate the use of liquid−liquid interfaces toward the formation of PbCrO4 nanoparticles and their subsequent time-dependent self-assembly at the air−water interface into nanorods by oriented attachment. EDAX and XPS analysis indicate the formation of stoichiometric PbCrO4. TEM studies at different stages of aging reveal that the transformation from nanoparticles to nanorods is kinetically governed. HRTEM analysis indicates nanorod growth along the [110] plane. UV−visible spectra reveal the presence of peaks at 425 and 515 nm for nanorods, while for the nanoparticle sample, a single peak at 425 nm is evident. As formation of ultrathin films over a large area (typically equal to or greater than 1µm × 1µm) concomitantly accompanies this approach, it can be extended to other materials as well for nanostructured device applications.