Design of superhydrophobic surfaces by synthesis of carbon nanotubes over Co–Mo nanocatalysts deposited under microwave irradiation on Ti-containing mesoporous silica thin films

Abstract

The superhydrophobic surface has been designed by the synthesis of carbon nanotubes (CNTs) on Ti-containing mesoporous silica thin films (Ti-MSTFs) with Co–Mo binary nanocatalysts. The active Co–Mo catalysts have been successfully deposited on Ti-MSTFs under microwave irradiation. SEM and TEM observations after CNT synthesis revealed that surfaces of Ti-MSTFs were densely covered with CNTs having a diameter of 15 nm. Raman spectra indicated that the undesired structural defects in the carbon network of the synthesized CNTs, which would lead to the formation of hydroxyl groups, were scarce. Interestingly, hydrophobic properties of samples after CNT synthesis were enhanced with increasing titanium concentration of Ti-MSTF, and the water contact angle reached up to 165° on Ti-MSTF with a titanium concentration of 10 at%. The combination of dispersed titanium oxide moieties within the silica frameworks and the microwave irradiation made a great contribution to deposit active Co–Mo catalysts responsible for the formation of well-dense CNTs.