Titania-based photocatalytic coatings on stainless steel hospital fixtures

A scaled-up pulsed-pressure MOCVD system was used to deposit TiO₂ coatings from tetra-isopropoxide precursor solution on stainless steel substrates and on 3-D objects. The objective of the work is the production of antimicrobial coatings for handles in health care facilities. Antimicrobial coatings are sought to manage the transmission of hospital acquired infections (HAI's), which are reported to cost around one million pounds per annum in the UK alone. Titania is a promising material for this application due to the photocatalytic production of reactive oxygen species that are crucial for the destruction of organic pathogens. TiO₂ coatings of 0.2 to 13 μm thickness were deposited at temperatures between 375 °C and 475 °C. The crystallite size and photocatalytic activity are influenced by deposition temperature. No dependence of stoichiometry on the deposition temperature has been observed. The films on stainless steel exhibit reasonably good photocatalytic performance. The photocatalytic performance and the stoichiometry improve with the film thickness. A three dimensional object (door handle) was coated with good conformity. The reactor scale-up for coating production on door handles is proposed for future wear and hygiene performance testing.