Single Particle Electrochemical Oxidation of Polyvinylpyrrolidone-Capped Silver Nanospheres, Nanocubes, and Nanoplates in Potassium Nitrate and Potassium Hydroxide Solutions

Single particle electrochemical oxidation of polyvinylpyrrolidone-capped silver nanoparticles at a microdisk electrode is investigated as function shape (spheres, cubes, and plates) in potassium nitrate hydroxide solutions. In nitrate, extreme anodic potentials (?1500 mV vs Ag/AgCl (3 M KCl)) are necessary to achieve oxidation, while lower required (?900 (saturated KCl)). Upon oxide formed, readily catalyzing water producing spike-step current response. The spike duration for each used probe effects on the mechanism, substantially shorter solution large overpotentials than solution. integration spikes indicates mixed-valence complex. both electrolytes, rate strongly depends content nanoparticles, rather shape-dependent variable–surface area. step height, which reflects also tracks more so shape. reactivity less-protected citrate-capped particles toward compared with that polymer-capped under these conditions