Functional Photocatalytic Surfaces for Selective Adsorption and Detection of Organic Pollutants

The dissertation focuses on using unique surface wettability properties to remove oil contamination from water. Three main ideas are explored. In Publication 1, a two-step photocatalytic reduction process creates hierarchical Au nanostructures on a TiO2 film, resulting in a stable surface with superhydrophobic properties. This surface is useful for self-cleaning and anti-icing technologies, as well as applications in cell growth and fluid microchips. Publication 2 introduces a "3-in-1" concept, combining a photocatalytic thin film, micro/nanostructuring, and a low surface energy coating. The resulting surface exhibits superhydrophobicity and photocatalytic activity, suitable for oil-water separation, self-cleaning, and water harvesting. The p-V3D3 coating's stability under UV irradiation and atomic oxygen exposure is advantageous. Publication 3 presents a 4N-in-1 hybrid substrate (AgTiO2) for enhanced Raman spectroscopy. This hybrid substrate achieves significant enhancement, high detection sensitivity, superior photocatalytic degradation performance, and long-term reusability.In summary, this dissertation explores the development of surfaces with unique wettability properties for oil-water separation, self-cleaning, water harvesting, and ultrasensitive Raman spectroscopy. The fabricated surfaces demonstrate improved hydrophilicity, superhydrophobicity, and photocatalytic activity, leading to enhanced performance in various applications

Nanoscale Synergetic Effects on Ag-TiO2 Hybrid Substrate for Photoinduced Enhanced Raman Spectroscopy (PIERS) with Ultra-Sensitivity and Reusability

Here, a 4N-in-1 hybrid substrate concept (nanocolumnar structures, nanocrack network, nanoscale mixed oxide phases, and nanometallic structures) for ultra-sensitive and reliable photo-induced-enhanced Raman spectroscopy (PIERS), is proposed. The use of the 4N-in-1 hybrid substrate leads to an ≈50-fold enhancement over the normal surface-enhanced Raman spectroscopy, which is recorded as the highest PIERS enhancement to date. In addition to an improved Raman signal, the 4N-in-1 hybrid substrate provides a high detection sensitivity which may be attributed to the activation possibility at extremely low UV irradiation dosage and prolonged relaxation time (long measurement time). Moreover, the 4N-in-1 hybrid substrate exhibits a superior photocatalytic degradation performance of analytes, allowing its reuse at least 18 times without any loss of PIERS activity. The use of the 4N-in-1 concept can be adapted to biomedicine, forensic, and security fields easily