A facile method for preparing thiocyanato-functionalized porous silica nanospheres

• A facile one-step sol–gel method was developed using cationic surfactants as template.
• Thiocyanato-functionalized porous silica nanospheres with size less than 23 nm were obtained.
• The porous structures and morphology of the samples could be controlled.

In this study, we present a facile method to prepare thiocyanato-functionalized porous silica nanospheres. Thiocyanato functionalized silica shells were coated on positively charged cetyltrimethylammonium bromide (CTAB) micelles via hydrolysis and condensation of (3-thiocyanatopropyl)triethoxysilane (TCPTES), the CTAB cores were removed subsequently to form thiocyanato-functionalized porous silica nanospheres. We demonstrate that the contents of the thiocyanato groups within the functionalized porous silica nanosphere frameworks gradually diminished as a function of hydrothermal treatment time at 100 °C until complete removal, confirmed by TGA and FTIR spectra. The data indicate that extended operation at relatively elevated temperatures may lead to the decomposition of the thiocyanato functional groups. In addition, at a lower CTAB concentration (0.0009 M), non-porous thiocyanato functionalized silica nanospheres were formed. However, increasing the CTAB concentration to 0.01 M resulted in porous nanospheres inferring that a CTAB concentration threshold is needed to form thiocyanato-functionalized porous silica nanospheres.

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