Single‐Entity Electrocatalysis of Individual “Picked‐and‐Dropped” Co₃O₄ Nanoparticles on the Tip of a Carbon Nanoelectrode

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.