Synergetic Codoping in Fluorinated Ti1-xZrxO2 Hollow Microspheres

The synergetic effects of codoped Zr4+ and F- ions within anatase hollow microspheres produced by a fluoride-mediated self-transformation strategy are investigated and discussed. The concomitant participation of F- promotes lattice substitution of Ti4+ ions by Zr4+ and facilitates the transformation of surface-segregated amorphous ZrOx clusters into Zr-F species. Codoping is associated with electron transfer-mediated charge compensation between the Zr/F impurities, which reduces the number of both bulk and surface defects and provides a stabilizing effect on the local structure. Moreover, these synergetic interactions influence the textural characteristics and surface states of the TiO2 host, such that the photocatalytic activity with regard to the decomposition of gaseous toluene is enhanced. Synergetic codoping of heterogeneous impurities within the host lattice or near-surface regions provides a general and effective alternative strategy for higher level doping and surface modification, which may be crucial for catalyst design and associated applications.