Viewing the Tube in 3D
New geometric method developed for evaluating metal nanoparticles on tubular structures
Schematic drawing (top), TEM image (left), and reconstructed tomography (right) showing the spatial distribution of catalyst particles on a hollow carbon nanofiber. Enlarge Image
Researchers used EMSL’s scanning transmission electron microscope (STEM) and tomography capabilities to test a new geometric method, based on two-dimensional TEM imaging, to extract three-dimensional information about the size and location of small catalytic particles supported on a tubular structure. The team included scientists from the University of Illinois, FEI Company, and EMSL. The accuracy of the new method, which applies only to nearly perfect cylindrical structures, was verified using standard tomography approaches available on the EMSL STEM. The new method provides an advantage over standard three-dimensional tomography imaging because it can be used without multiple angle measurements and enables the viewer to distinguish exactly where on a tubular structure the particle is located. The research team used the method to analyze the amount of palladium nanoparticles loaded inside versus outside hollow carbon nanofibers (CNF). The location of metal catalyst particles relative to the supporting CNF critically influences the catalytic properties of the entire system, which could include technologies for water purification and emissions control.
Reference: Shuai D, CM Wang, A Genç, and CJ Werth. 2011. J. Phys. Chem. Lett., 2, pp 1082–1087, DOI: 10.1021/jz2003815.
Acknowledgement: This work was supported by Water CAMPWS, a Science and Technology Center program of the National Science Foundation. This research was made possible by American Recovery and Reinvestment Act funding.
Released: May 24, 2011
