Preparation of highly stable superhydrophobic TiO2 surfaces with completely suppressed photocatalytic activity

TiO2 nanoparticles with a mean size of 20–30 nm were covered by ultrathin polydimethylsiloxane (PDMS) film, which shows hydrophobic properties. Surfaces consisting of the PDMS-coated TiO2 particles showed water contact angles close to 170°. In contrast to the hydrophobic films consisting of organic molecules, which can be photocatalytically decomposed on TiO2 in the presence of UV light, PDMS-coating on TiO2 was highly stable. The PDMS-coating completely suppressed the photocatalytic activity of TiO2. The unique properties of PDMS-coating can be exploited for UV protection layer and self-cleaning surfaces.

► TiO2 nanoparticles were coated with ultrathin polydimethylsiloxane (PDMS) film.
► Superhydrophobicity was observed from the surface consisting of PDMS-coated TiO2.
► Photocatalytic activity was completely suppressed by the PDMS-coating.
► Our result is of potential importance for UV protection.