Precise control the microstructural, optical, photocatalytic, and photoelectrochemical properties of TiO 2 nanoarrays through changing with growth substrate via hydrothermal method

A series of TiO2 nanostructures with rutile phase were synthesized on arbitrary substrates of conductive transparent fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and glass at the low temperature of 150 °C by the hydrothermal method. The samples were characterized by XRD, SEM, TEM, XPS, UV–Vis absorption, and micro-Raman spectroscopy. The effects of growth substrates on the morphologies and optical properties of nanostructures were investigated. TiO2 nanorods were grown on the FTO substrate, while TiO2 nanoflowers were grown on the ITO and glass substrates, and the growth mechanism for these different nanostructures is discussed in detail. The results show that the TiO2 nanorods can improve photocatalytic properties and photoelctrochemical (PEC) performance for its unique structure and optical properties. The TiO2 nanorods exhibited a maximal photocatalytic rate of 4.42 min−1 and photocurrent density of 0.049 mA/cm2, which is about 1.52 and 3.03 times higher than those of TiO2 nanoflowers grown on the ITO substrates, respectively. These findings are quite promising and encouraging for the use of TiO2 nanoarrays in photocatalysis and energy applications.