Hybrid CuxO/TiO2 Nanocomposites As Risk-Reduction Materials in Indoor Environments

Photocatalytic TiO2 powders impart ultraviolet light-induced self-cleaning and antibacterial functions when coated on outdoor building materials. For indoor applications, however, TiO2 must be modified for visible-light and dark sensitivity. Here we report that the grafting of nanometer-sized CuxO clusters onto TiO2 generates an excellent risk-reduction material in indoor environments. X-ray absorption near-edge structure using synchrotron radiation and high-resolution transmission electron microscopic analyses revealed that CuxO clusters were composed of Cu-I and Cu-II valence states. The Cu-II species in the CuxO clusters endow TiO2 with efficient visible-light photooxidation of volatile organic compounds, whereas the Cu-I species Impart antimicrobial properties under dark conditions. By controlling the balance between Cu-I and Cu-II in CuxO, efficient decomposition and antipathogenic activity were achieved in the hybrid CuxO/TiO2 nanocomposites.