Controlled synthesis of semiconductor PbWO4 nanocrystals inside silica SBA-15 materials

A new flexible approach is developed to synthesize PbWO4 nanoparticles inside the channels of mesoporous silica SBA-15. Mesoporous SBA-15 silica with 7 nm pores was produced by a hydrothermal process and used as a hard template. PbWO4 nanoparticles were synthesized and incorporated into the mesoporous silicate support in a low-power ultrasonication condition. The as-synthesized samples were characterized by Raman spectroscopy, diffuse reflectance UV–vis spectroscopy (UV–vis), powder X-ray diffraction (XRD), small-angle X-ray diffraction (SAXRD), nitrogen adsorption and transmission electron microscopy (TEM). It was found that PbWO4 nanoparticles appeared among the channels of SBA-15. Blue shift was observed in UV–vis absorption spectra due to the quantum size effect of PbWO4 nanoparticles. This preparation method is also capable of synthesis of various semiconductor nanoparticles with controlled size and morphology inside the channels of mesoporous materials.