Photo‐Induced Self‐Cleaning and Wettability in TiO₂ Nanocolumn Arrays Obtained by Glancing‐Angle Deposition with Sputtering

Abstract

In this work, the preparation of regular nanosized columnar structures of titanium dioxide by means of glancing angle deposition with magnetron sputtering (MS‐GLAD) followed by thermal annealing is reported. MS‐GLAD gives rise to metallic titanium columnar structures with regular width and length that after thermal treatment are fully oxidized to form TiO2 nanocolumns that maintain the morphological features of the original metallic ones. Further functionalization with gold by means of multiple ion cluster source results in well‐dispersed Au nanoparticles across the nanocolumns’ surface with a narrow size distribution centered at ca. 8.5 nm. The obtained nanostructures show photocatalytic self‐cleaning activity as shown by the elimination of an organic layer deposited on their surface and the detection of hydroxyl radicals. Photoelectrochemical measurements show a better charge separation at the Au/TiO2 interface. In addition, wettability studies show that the degree of hydrophobicity of the surface is increased by the presence of nanocolumns, both in the dark and under UV illumination. This behavior is not modified by the presence of Au nanoparticles on the surface. The obtained results open up interesting implications in the tunability of the properties of nanostructured thin films for this kind of photo‐activated application.

Bio-Inspired Hierarchical Micro/Nanostructured Surfaces for Superhydrophobic and Anti-Ice Applications

“…The micropillar gap, area fractions, heights can be easily defined by the UV-lithography and the DRIE etching step. The nanowire heights, material type can be optimized in the GLAD step by changing the deposition time and using more thermally insulative target materials such as titanium oxide (TiO2) ( Fresno et al, 2021 ) and tin oxide (SnO2) ( Chetri and Dhar, 2019 ). The gap of the GLAD nanowires is more difficult to change mostly determined by the initial nucleation but can be controlled in certain degrees using a prefabricated seed layer ( Dick et al, 2003 ).…”

CdIn2S4‐xSex Solid‐Solution Nanocrystal Photocatalyst: One‐Step Hydrothermal Synthesis, Controllable Band Structure, and Improved H2‐Evolution Activity

“…Photocatalytic hydrogen evolution by splitting water over semiconductors has been deemed as one of the effective methods to resolve the energy crisis and environmental pollution. [1][2][3][4][5][6] Among the semiconductors, TiO 2 has been widely applied in bandgap structure represented a higher photocatalytic H 2 -generation performance. However, the introduction of Se into metal chalcogenide to produce corresponding metal sulfoselenide solid-solution photocatalyst is still very limited, possibly owing to the absence of their effective synthesis route.…”

“…Photocatalytic hydrogen evolution by splitting water over semiconductors has been deemed as one of the effective methods to resolve the energy crisis and environmental pollution. [ 1–6 ] Among the semiconductors, TiO 2 has been widely applied in the aspect of photocatalytic H 2 evolution owing to its non‐toxic properties, chemical stability, and abundant sources. [ 7–10 ] However, the low light‐absorption range of traditional TiO 2 (only absorbing UV light) limits the further applications.…”

Hierarchical TiO2 Layers Prepared by Plasma Jets

“…A typical example 2 of 15 is a reactive magnetron sputtering system of titanium sputtered in Ar and O 2 gas mixture atmosphere [1][2][3]. This method can provide TiO 2 layers with excellent adhesion and semiconductor properties, fulfilling sufficient photocatalytic performance as well [4,5]. Furthermore, the reactive magnetron sputtering of TiO 2 is routinely used at the industrial scale to coat a large surface (i.e., windows or foils).…”