Silica nanoparticles were linked by using 3‐mercaptopropyltrimethoxysilane (MPS) as a coupling agent and Cd2+ as bridging ions. The TEM micrographs showed approximately linear linkage between the silica nanoparticles rather than dense packing. The UV‐visible absorption spectra confirmed the formation of S‐Cd‐S bonds between the silica nanoparticles. The alternative films of MPS‐modified SiO2 nanoparticles and Cd2+ ions were also prepared using the layer‐by‐layer self‐assembly technique and characterized by AFM.
Acknowledgments
This work was financially supported by Excellent Young Teacher Program and Research Foundation of Returned Student Abroad, MOE of China. The authors also thank Shanghai Education Committee for support.