Selective Adsorption and Photocatalytic Clean‐Up of Oil by TiO₂ Thin Film Decorated with p‐V₃D₃ Modified Flowerlike Ag Nanoplates

Abstract Various methods are developed and used to treat oil‐contaminated water, including mechanical separation, chemical treatment, biological treatment, membrane filtration, and sorption. Oil clean‐up via selective sorption of the oil by an engineered surface is the most accepted technique due to its high removal efficiency and low cost. Here, a multifunctional surface providing highly selective oil sorption and clean‐up capability via the photocatalytic decomposition is proposed. This novel surface is named as the “three‐in‐one (3‐in‐1) surface” since it is composed of 1) a highly photocatalytic layer, 2) micro‐ and nanostructures, and 3) a low surface energy layer. First, the TiO₂ photocatalytic layer is prepared by magnetron sputtering. Then flowerlike Ag nanoplates are photocatalytically deposited on the sputtered TiO₂ layer. Afterward, a low surface energy layer, poly‐1,3,5‐trivinyl‐1,3,5‐trimethylcyclotrisiloxane (p‐V₃D₃), is over‐coated on Ag/TiO₂ surface by initiated chemical vapor deposition (iCVD) while retaining the topographical features of the surface (micro‐ and nanoscale surface structures). The p‐V₃D₃/Ag/TiO₂ surface demonstrates a high selective adsorption to oil whereas simultaneously it shows extreme repellency to water. The p‐V₃D₃/Ag/TiO₂ surface can also be photocatalytically cleaned up and this may find applications in various technology fields including water treatment, microfluidics, self‐cleaning, and water harvesting.