Tenfold improvement in the sensitivity of electron holography reveals the net charge in a single platinum nanoparticle with a precision of just one electron, providing fundamental information for developing future catalysts.
If you often find yourself off by one when counting your socks after doing the laundry, you might want to sit down for this.
Scientists in Japan have now counted the number of extra—or missing—charges down to a precision of just one electron in single platinum nanoparticles having diameters only one-tenth those of common viruses.
This new process for precisely studying differences in net charge on metal nanoparticles will aid in the further understanding and development of catalysts for breaking down greenhouse and other harmful gases into fuels and benign gases or for efficiently producing ammonia needed for fertilizers used in agriculture.
Led by Kyushu University and Hitachi Ltd., the research team achieved this feat of extreme counting through hardware and software improvements that increased tenfold the sensitivity of a technique called electron holography.
While transmission electron microscopy uses a beam of electrons to observe materials down to the atomic level, electron holography utilizes the wave-like properties of electrons to probe electric and magnetic fields.
Interaction of an electron with fields causes a phase shift in its wave that can be identified by comparing it with a reference wave of an unaffected electron.
In the new work, the researchers focused their microscopes on single nanoparticles of platinum on a surface of titanium oxide, a combination of materials that is already known to act as a catalyst and speed up chemical reactions.
On average, the platinum nanoparticles had diameters of only 10 nm—so small that it would take nearly 100,000 to span one millimeter.
“While each particle contains a few tens of thousands of atoms of platinum, the addition or removal of just one or two negatively charged electrons causes significant changes in the behavior of the materials as catalysts,” says Ryotaro Aso, associate professor at Kyushu University’s Faculty of Engineering and first author on the paper in the journal Science reporting the work.
For more information about this research, see “Direct identification of the charge state in a single platinum nanoparticle on titanium oxide,” Ryotaro Aso, Hajime Hojo, Yoshio Takahashi, Tetsuya Akashi, Yoshihiro Midoh, Fumiaki Ichihashi, Hiroshi Nakajima, Takehiro Tamaoka, Kunio Yubuta, Hiroshi Nakanishi, Hisahiro Einaga, Toshiaki Tanigaki, Hiroyuki Shinada, and Yasukazu Murakami, Science (2022).https://doi.org/10.1126/science.abq5868
Press release here.