Self-Aligned Growth of Hexagonal TiO2 Nanosphere Arrays on α-MoO3 (010) Surface

At present there are two basic types of self-assembly of inorganic nanomaterials: surfactant-assisted organization and patterned-substrate deposition. In this paper, we report a novel assembled scheme for fabrication of hexagonal superlattice arrays of anatase TiO 2 nanospheres on the (010) crystal plane of α-MoO 3 without the assistance of organic surfactants or substrate prefabrication. The growth and self-assembly of TiO 2 nanospheres take place simultaneously under hydrothermal conditions at 150−200 °C according to a continuous self-aligned process in which the localized enrichment of hydrolysis product HF (TiF 4 is the precursor for TiO 2 ) is believed to play a crucial role in initiating the self-alignment. This “growth-cum-assembly” mechanism has also been validated with our various growth experiments and materials characterization. Key synthetic parameters have been identified and future explorations have been suggested for this ordered scheme.