Review of recent nano TiO ₂ film coating methods, assessment techniques, and key problems for scaleup

Abstract The growing demand for green and sustainable development positions TiO 2 film coatings at the forefront of novel technologies. Applications of TiO 2 -based materials in photocatalytic, optic, energy, electronic, aerospace, automotive, decorative, and other fields have accelerated on a large scale. Various coating processes are widely used in order to prepare nano TiO 2 filmcoated supports for different purposes. Each technique offers numerous advantages, such as the potential to be produced in large quantities and surface areas, acceptable adherence and reactivity of the resulting product, cost-effectiveness, simplicity, etc. This work provides a comprehensive overview of the most recent as well as commonly applied wet and dry TiO 2 deposition methods in terms of principals, advantages, applications, coating assessment techniques, required equipment, and key technical problems for mass production and commercialization such as coating durability, fouling, cost-effectiveness, environmental impacts, etc. This information provides a basis to better understand the new and conventional coating processes and the relative contribution rate of the influencing factors that are necessary to control the physicochemical properties of resulting coated substances for the applications aimed.