Photocatalytic TiO2 thin films and coatings prepared by sol–gel processing: a brief review

• Published in: Journal of sol-gel science and technology Vol. 102; no. 1; pp. 125 - 141
• Main Authors: Obregón, Sergio, Rodríguez-González, Vicente
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2022; Springer Nature B.V
• Subjects: Air purification; Antiinfectives and antibacterials; Ceramics; Chemical properties; Chemistry and Materials Science; Clean energy; Composites; Dip coatings; Electrophoretic deposition; Gas sensors; Glass; Immersion coating; Inorganic Chemistry; Materials Science; Megacities; Microorganisms; Nanotechnology; Natural Materials; Optical and Electronic Materials; Organic compounds; Photocatalysis; Pollutants; Public transportation; Review Paper: Sol–gel and hybrid materials with surface modification for applications; Shopping malls; Sol-gel processes; Solar radiation; sol–gel Research in Latin America; Spin coating; Spray pyrolysis; Thin films; Titanium dioxide; Water purification; Water splitting; Thin films; TiO; Sol–gel; Coatings; Photocatalysis
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-021-05628-5

The use of nanostructured coatings is crucial to maintain clean surfaces in public transport, shopping malls, parks, and hospitals. Megacities produce large amounts of pollutants in water and air, making it necessary to develop strategies to prevent diseases caused by accumulation of organic compounds, bacteria, viruses, and other harmful microorganisms on surfaces. This concise review analyzes the fundamental deposition techniques based on the sol–gel process for the preparation of TiO 2 films and coatings. In this regard, methodologies such as dip-coating, spin coating, spray pyrolysis, and electrophoretic sol–gel deposition are reviewed in detail. Outstanding properties such as chemical stability, reusability, hydrophilicity, and activation by sunlight or simulated solar radiation position these TiO 2 thin films and coatings as a suitable technology for commercial devices that keep public surfaces clean. Environmental and energy applications including water and air purification, gas sensing, production of renewable fuels from water splitting and CO 2 photoreduction, as well as antimicrobial features of the sol–gel-based TiO 2 coatings can be considered as potential and valuable strategies to control pollution in the actual worldwide societies. Highlights Sol–gel methodologies are essential techniques for preparation of TiO 2 thin films and coatings. Dip/spin coating, spray pyrolysis and electrophoretic sol–gel deposition are reviewed in detail. Physical and chemical properties of TiO 2 films are modified according to the sol–gel methodology. Several photocatalytic applications of TiO 2 films derived from sol–gel techniques are discussed.