Tailored TiO2-SrTiO3 heterostructure nanotube arrays for improved photoelectrochemical performance.
TiO(2) nanotube arrays formed on Ti substrate by electrochemical anodization have been converted into TiO(2)-SrTiO(3) heterostructures by controlled substitution of Sr under hydrothermal conditions. The growth of SrTiO(3) crystallites on the nanotube array electrode was probed by electron microscopy and X-ray diffraction. As the degree of Sr substitution increases with the duration of hydrothermal treatment, an increase in the size of SrTiO(3) crystallites was observed. Consequently, with increasing SrTiO(3) fraction in the TiO(2)-SrTiO(3) nanotube arrays, we observed a shift in the flat band potential to more negative potentials, thus confirming the influence of SrTiO(3) in the modification of the photoelectrochemical properties. The TiO(2)-SrTiO(3) composite heterostructures obtained with 1 h or less hydrothermal treatment exhibit the best photoelectrochemical performance with nearly 100% increase in external quantum efficiency at 360 nm. The results presented here provide a convenient way to tailor the photoelectrochemical properties of TiO(2)-SrTiO(3) nanotube array electrodes and employ them for dye- or quantum-dot-sensitized solar cells and/or photocatalytic hydrogen production.
Zhang
Jun
J
Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Bang
Jin Ho
JH
Tang
Cencun
C
Kamat
Prashant V
PV
D002384:Catalysis; D004563:Electrochemistry; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D055668:Photochemical Processes; D013324:Strontium / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
D010087:Oxides; C009495:titanium dioxide; D014025:Titanium; C119252:strontium titanium oxide; D013324:Strontium