A New Method of Preparing Alkanethiol-Protected Gold Nanoparticals

摘要

In a new two-phase system (tetrahydrofuran/saturated NaCl aqueous solution) monolayer protected clusters (MPCs) were prepared. The AuCl_4~- anion in saturated electrolyte aqueous solution was transferred into the organic phase of tetrahydrofuran by tetra-n-butylammonium bromide ((C_4H_9)_4 NBr) and was reduced quickly by sodium borohydride in the presence of alkanethiol. The functionalized MPCs were characterized by solubility, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX) analysis and UV-vis spectroscopy. Electrochemical measurements of MPCs in CH_2 Cl_2 exhibited 7 pairs of reversible Voltammetric waves within the potential range of -1.0 to 1.0V (vs Ag/AgCl), which was ascribed to the quantized capacitance charging of nanoparticle double layers. All the results show that the new preparing method is feasible.