Oxidation of copper nanoparticles in water: mechanistic insights revealed by oxygen uptake and spectroscopic methods
N.L. Pacioni, V. Filippenko, N. Presseau and J.C. Scaiano, "Oxidation of copper nanoparticles in water: mechanistic insights revealed by oxygen uptake and spectroscopic methods", Dalton Trans., 42 (16), 5832-5838 (2013).
Oxidation of aqueous ~8 nm unprotected copper nanoparticles takes place under air in approximately 2 hours at 30°C to give Cu2+ as a final product through an intermediate Cu+ species. At 5°C the process is about 5 times slower; similarly, vitamin C, which plays a sacrificial role, also slows down the oxidation, while CuNP catalyses its oxidation. In this work, we present a detailed analysis of the oxidation mechanism of colloidal CuNP inferred through spectroscopic methods (UV-visible and EPR) combined with oxygen uptake measurements, with emphasis in factors affecting the oxidative process.