Corrosion Resistance of Thiol- and Alkene-Passivated Germanium Nanowires

The corrosion resistance of organic monolayer-coated germanium (Ge) nanowires was tested by exposure to various harsh chemical treatments, including boiling water, concentrated sulfuric acid, and hydrogen peroxide. The Ge nanowires were grown by the supercritical fluid liquid solid (SFLS) process with in situ thermal hydrogermylation or thiolation, with alkyl monolayer coatings of varying chain length, from 6 to 18 C atoms. All of these nanowires exhibited almost-imperceptible surface oxidation in air or water, and degraded only when exposed to the harshest oxidative conditions. Nanowires with monolayers attached through Ge C and Ge S bonds exhibited similar corrosion resistance, except when exposed to peroxide, in which case the alkylated nanowires were more resistant to oxidation.