TiO2-SiO2 nanoparticles for suppressing photocatalytic activities and improving hydrophilicity

Abstract

Titanium dioxide (TiO2) has attracted significant attention because of its photocatalytic and UV absorbance properties. However, despite the good UV-shielding property of TiO2, it is not suitable for use in outdoor UV-shielding protective films because of its strong photocatalytic behavior when absorbing UV radiation. Here, we describe a TiO2@SiO2 core shell structure with uniform and thin SiO2 layer; the SiO2 shell suppresses TiO2 photocatalytic activity and improves the wettability of the TiO2. TiO2@SiO2 nanoparticles were characterized by TEM, FT-IR, XPS, and VB-XPS. A uniform, thin SiO2 shell suppressed the photocatalytic activity of the TiO2 core by broadening the band gap because of the existence of Ti-O-Si chemical bonds at the interface of TiO2 and SiO2. Moreover, the increase in wettability of the TiO2@SiO2-coated films observed was a permanent property and did not require UV activation.

This work was supported by the Industrial Core Technology Development Program funded by Ministry of Knowledge Economy (No. 10030837, Titania nano powder coating material technology for application development) and by the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (2010T100100965) grant funded by the Korea Government Ministry of Knowledge Economy.