Functionalization of silicon nanoparticles via silanization: Alkyl, halide and ester

The feasibility of using silanization as a general tool to functionalize the surface of silicon nanoparticles (NPs) has been investigated in detail. Silicon NPs were prepared from reduction of silicon tetrachloride with sodium naphthalide. The terminal chloride on the surface of as-synthesized particles was substituted by methanol and water, in sequence. The particles were then silanized by octyltrichlorosilane, 11-bromoundecyltrichlorosilane, or 2-(carbomethoxy)ethyltrichlorosilane. These treatments yielded alkyl-, bromo-, or ester-termini on NP surfaces, respectively. The NPs were characterized by TEM, NMR, FTIR, UV-Vis, and PL spectroscopy. Changes of termination groups brought various functionalities to the NPs, without loss of the photophysics of the original NPs.