Single‐Entity Electrocatalysis of Individual “Picked‐and‐Dropped” Co<sub>3</sub>O<sub>4</sub> Nanoparticles on the Tip of a Carbon Nanoelectrode
Thomas Quast, Harshitha Barike Aiyappa, Sascha Saddeler, Patrick Wilde, Yen‐Ting Chen, Stephan Schulz, Wolfgang Schuhmann
Abstract
Abstract Nano‐electrochemical tools to assess individual catalyst entities are critical to comprehend single‐entity measurements. The intrinsic electrocatalytic activity of an individual well‐defined Co 3 O 4 nanoparticle supported on a carbon‐based nanoelectrode is determined by employing an efficient SEM‐controlled robotic technique for picking and placing a single catalyst particle onto a modified carbon nanoelectrode surface. The stable nanoassembly is microscopically investigated and subsequently electrochemically characterized. The hexagonal‐shaped Co 3 O 4 nanoparticles demonstrate size‐dependent electrochemical activity and exhibit very high catalytic activity with a current density of up to 11.5 A cm −2 at 1.92 V (vs. RHE), and a turnover frequency of 532±100 s −1 at 1.92 V (vs. RHE) towards catalyzing the oxygen evolution reaction.