Influence of the Micro-Nanostructuring of Titanium Dioxide Films on the Photocatalytic Degradation of Formic Acid under UV Illumination

• Published in: Nanomaterials (Basel, Switzerland) Vol. 12; no. 6; p. 1008
• Main Authors: Crespo-Monteiro, Nicolas, Hamandi, Marwa, Usuga Higuita, Maria Alejandra, Guillard, Chantal, Dappozze, Frederic, Jamon, Damien, Vocanson, Francis, Jourlin, Yves
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.03.2022; MDPI
• Subjects: Anatase; Atomic force microscopy; Catalysis; Chemical Sciences; Chemistry; Coatings; Crystallization; Degradation; Efficiency; Ellipsometry; Ethanol; Formic acid; Glass substrates; Hydrophobicity; Illumination; Light; Material chemistry; micro-nanostructuring; Microspheres; Photocatalysis; Photodegradation; Polymethyl methacrylate; Raman spectroscopy; Scanning electron microscopy; sol-gel; Sol-gel processes; Thickness; Thin films; Titanium; Titanium dioxide; Tribology; Ultraviolet radiation; France; United States > US; formic acid; micro-nanostructuring; photocatalysis; sol-gel
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano12061008

Surface micro-nanostructuring can provide new functionalities and properties to coatings. For example, it can improve the absorption efficiency, hydrophobicity and/or tribology properties. In this context, we studied the influence of micro-nanostructuring on the photocatalytic efficiency of sol-gel TiO coatings during formic acid degradation under UV illumination. The micro-nanostructuring was performed using the UV illumination of microspheres deposited on a photopatternable sol-gel layer, leading to a hexagonal arrangement of micropillars after development. The structures and coatings were characterized using Raman spectroscopy, ellipsometry, atomic force microscopy and scanning electron microscopy. When the sol-gel TiO films were unstructured and untreated at 500 °C, their effect on formic acid's degradation under UV light was negligible. However, when the films were annealed at 500 °C, they crystallized in the anatase phase and affected the degradation of formic acid under UV light, also depending on the thickness of the layer. Finally, we demonstrated that surface micro-nanostructuring in the form of nanopillars can significantly increase the photocatalytic efficiency of a coating during the degradation of formic acid under UV light.