Development of Photocatalytic Self-cleaning 316 Stainless Steel Surface

Surfaces that can keep themselves clean are described as self-cleaning surfaces. Such surfaces have drawn a lot of attention due to their numerous applications in food, aerospace, manufacturing and other industries. Self-cleaning for metals and alloys is usually achieved by creating hydrophobic textured surfaces. However, such surfaces obtained by texturing are unstable as their wettability changes over time. An alternative to creating self-cleaning surfaces is through the photocatalytic effect where a semiconductor material can generate radicals to remove organic contaminants upon the illumination of UV light. We studied the photocatalytic efficiency of TiO₂ coating deposited on smooth and textured 316 stainless steel surfaces. Thermal oxidation at different temperatures was explored to study how it affects the photocatalytic efficiency of TiO₂ coating. The results showed that the textured surfaces achieved a good bonding of TiO₂ coating and a better self-cleaning effect as compared to the smooth samples. Generally, a better self-cleaning effect could be observed for TiO₂ films that were obtained by thermally oxidising Ti films at around 500 °C.