Tailoring morphology, structure and photoluminescence properties of anodic TiO₂nanotubes

Abstract

TiO2 nanotube (TNT) structures were grown perpendicular to fluorine‐doped tin‐oxide‐coated glass substrates by anodic oxidation of titanium films. The morphology, crystal structure and optical properties of the TNTs were shown to be dependent on the thickness of the titanium film, which acts as an electrode in electrochemical anodization. Field emission scanning electron microscopy measurements revealed that an increase in titanium thickness from 1.5 to 2.7 µm caused a considerable increase in both inner diameter and tube length, which in turn increases the porosity and the physical surface of the TNTs per unit area. Grazing‐incidence small‐angle scattering was used to infer the statistical lateral ordering of the TNTs over macroscopic length scales. X‐ray diffraction data show an increase in the texture coefficient for the (004) plane as well as the I004/I101 intensity ratio with titanium film thickness. All these factors lead to a significant improvement in the photoluminescence intensity from titania nanotubes, which is about five times more than from titania nanoporous materials under similar circumstances.

Comparison of UV Irradiation and Sintering on Mesoporous Spongelike ZnO Films Prepared from PS-b-P4VP Templated Sol–Gel Synthesis

“…Investigating the nanostructure buried inside the ZnO films is also of critical importance, as the inner morphology can be different from that at the surface. , Specifically, for ssDSSCs, an inner porous structure is absolutely necessary to allow the dye molecules and HTM to be backfilled into the pores of ZnO films. Accordingly, GISAXS measurements are performed at an incident angle of 0.35°, which is larger than the critical angle of the ZnO.…”

Study of the Photocatalytic Properties of Ni-Doped Nanotubular Titanium Oxide

“…Conversely, a higher Ni 2+ content in the electrolyte in the immersion approach forces the preferred orientation degree of anatase, which was recently considered in papers [11,45,46]. The disappearance of the (101) plane could be associated with a blocking effect due to the absorption of Ni onto the surface between the (101) planes, which was also considered in [47].…”

“…Such different paths of nickel doping result in preferred crystallization along different crystallographic axes. Conversely, a higher Ni 2+ content in the electrolyte in the immersion approach forces the preferred orientation degree of anatase, which was recently considered in papers [11,45,46]. The disappearance of the (101) plane could be associated with a blocking effect As the lattice parameters remain unchanged, nickel is present at the surface of the NTO.…”