Hybrid Cu _xO/TiO _2 nanocomposites as risk-reduction materials in indoor environments

摘要

Photocatalytic TiO _2 powders impart ultraviolet light-induced self-cleaning and antibacterial functions when coated on outdoor building materials. For indoor applications, however, TiO _2 must be modified for visible-light and dark sensitivity. Here we report that the grafting of nanometer-sized Cu _xO clusters onto TiO _2 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 Cu _xO clusters were composed of Cu ~I and Cu ~(II) valence states. The Cu ~(II) species in the Cu _xO clusters endow TiO _2 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 Cu _xO, efficient decomposition and antipathogenic activity were achieved in the hybrid Cu _xO/TiO _2 nanocomposites.