New research possibilities at NanoMAX

X-rays can penetrate materials and are therefore useful for studying chemical processes as they occur inside reactors, cells, and batteries.
A common ingredient in such chemical systems is metal nanoparticles, which are often used as catalysts for important reactions. As the
NanoMAX beamline provides a very small X-ray focal spot, single nanoparticles can in principle be studied as they perform their
catalytic functions.

In this paper, we show that gold nanoparticles sitting inside an electrochemical cell can be imaged at NanoMAX. These preliminary
results come from nanoparticles around 60 nm (60 millionths of a millimetre) in size, and we show that even smaller particles could be
studied. If successful, future experiments will allow “filming” nanoparticles as they catalyze reactions in real-time, and give new
understanding of how catalysis works. That could in turn help design new materials for energy conversion, chemical production, and water
purification.

Experiments of this type have been reported before, but our findings show that the brilliance of the MAX IV storage ring allows imaging
smaller particles, that are more relevant for real-world applications. NanoMAX is designed to make full use of MAX IV’s high-quality beams,
and this paper shows one way in which the facility opens up new research possibilities.

Read the paper here (open access)

Experimental geometry showing the cell and a truncated octahedron lying on a (111)-type facet, representing a typical orientation of the particles studied. Also shown is the simulated exit wave and diffracted intensity for a given orientation φ assuming flat illumination and perfect alignment with respect to the rocking angle θ. Under these conditions and with the strain-free model particle, the exit wave is real-valued.

Coherent Bragg imaging of 60 nm Au nanoparticles under electrochemical control at the NanoMAX beamline

A. BjörlingD. CarboneF. J. SarabiaS. HammarbergJ. M. Feliu and J. Solla-Gullón

J. Synchrotron Rad. (2019). 261830-1834
https://doi.org/10.1107/S1600577519010385