Reactive and Organosoluble SnO2 Nanoparticles by a Surfactant-Free Non-Hydrolytic Sol-Gel Route

Reactive SnO2 nanoparticles have been successfully prepared by a simple non-hydrolytic sol-gel synthesis in CH2Cl2 at 110 degrees C by using SnCl4 as a precursor and diisopropyl ether (iPr(2)O) as an oxygen donor. The SnO2 nanocrystals, with a diameter of about 4 nm, formed stable sols in organic aprotic solvents in the absence of any surfactant or coordinating agent. The lack of aggregation has been attributed to the presence of Cl and OiPr surface groups instead of OH groups. These surface groups render the nanoparticles reactive towards hydroxylated surfaces, as shown by their reaction with an oxidized silicon wafer; the nanoparticles bind uniformly across the wafer to form a monolayer.