Titanium oxide (TiO₂) and iron oxide (α-Fe₂O₃) hematite films have potential applications as photoanodes in electrochemical water splitting. In the present work TiO₂ and α-Fe₂O₃ thin films were prepared by two methods, e.g., sol-gel and High Power Impulse Magnetron Sputtering (HiPIMS) and judged on the basis of physical properties such as crystalline structure and surface topography and functional properties such as simulated photoelectrochemical (PEC) water splitting conditions. It was revealed that the HiPIMS method already provides crystalline structures of anatase TiO₂ and hematite Fe₂O₃ during the deposition, whereas to finalize the sol-gel route the as-deposited films must always be annealed to obtain the crystalline phase. Regarding the PEC activity, both TiO₂ films show similar photocurrent density, but only when illuminated by UV light. A different situation was observed for hematite films where plasmatic films showed a tenfold enhancement of the stable photocurrent density over the sol-gel hematite films for both UV and visible irradiation. The superior properties of plasmatic films could be explained by ability to address some of the hematite drawbacks by the deposition of very thin films (25 nm) consisting of small densely packed particles and by doping with Sn.

A novel 1D nanotubular TiO ₂ /MoS ₂ nanosheet heterostructure possesses synergistic effects that yield superior photon-to-electron conversion and photocatalysis.

In this work, for the first time 3D Ti-Nb meshes of different composition, i.e., Ti, Ti-1Nb, Ti-5Nb, and Ti-10 Nb, were produced by direct ink writing. This additive manufacturing method allows tuning of the mesh composition by simple blending of pure Ti and Nb powders. The 3D meshes are extremely robust with a high compressive strength, giving potential use in photocatalytic flow-through systems. After successful wireless anodization of the 3D meshes toward Nb-doped TiO₂ nanotube (TNT) layers using bipolar electrochemistry, they were employed for the first time for photocatalytic degradation of acetaldehyde in a flow-through reactor built based on ISO standards. Nb-doped TNT layers with low concentrations of Nb show superior photocatalytic performance compared with nondoped TNT layers due to the lower amount of recombination surface centers. High concentrations of Nb lead to an increased number of recombination centers within the TNT layers and reduce the photocatalytic degradation rates.