Hybrid Cu x O/TiO2 Nanocomposites As Risk-Reduction Materials in Indoor Environments

• Published in: ACS nano 2012-02, Vol.6 (2), p.1609-1618
• Main Authors: Qiu, Xiaoqing, Miyauchi, Masahiro, Sunada, Kayano, Minoshima, Masafumi, Liu, Min, Lu, Yue, Li, Ding, Shimodaira, Yoshiki, Hosogi, Yasuhiro, Kuroda, Yasushi, Hashimoto, Kazuhito
• Format: Article
• Language: English
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn2045888

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 Cu x O 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 Cu x O clusters were composed of CuI and CuII valence states. The CuII species in the Cu x O clusters endow TiO2 with efficient visible-light photooxidation of volatile organic compounds, whereas the CuI species impart antimicrobial properties under dark conditions. By controlling the balance between CuI and CuII in Cu x O, efficient decomposition and antipathogenic activity were achieved in the hybrid Cu x O/TiO2 nanocomposites.