Characterising gold nanoparticles at atomic resolution might improve our understanding of the catalytic activity of these materials, according to an international team. These researchers (Kornberg et al) have now demonstrated that it is possible to use electron microscopy to obtain data on at least one gold cluster of greater than 1 nm diameter and to validate the results by comparison with small-angle X-ray scattering data, infrared absorption spectra and density functional theory calculations.
I had some independent commentary from an expert in the field, Mikael Johansson of the Technical University of Munich, Germany, that made it to the article but also some wise words from Chris Ackerson of Colorado State University that were a little too late to include in the Chemistry World article:
“Many cluster or nanoparticle compounds are solved by single crystal x-ray methods, but these total structure determination methods become difficult to apply to clusters with more than about 100 metallic atoms,” he told me. “The recent work of Kornberg’s group opens a new methodological door to structure determination of large metallic cluster and nanocrystal compounds. Of course, electron microscopy is routinely used to examine clusters and nanocrystals, even with atomic resolution. But previous electron microscopy methods obscured information on the surfaces arrangement of atoms and their ligation, due in part to the large electron doses used. The new method demonstrated by Kornberg reveals the surfaces of nanoparticles with high fidelity, and represents a real breakthrough in this respect.”