Synthesis of chemically bound conjugated polymer on TiO2 for a visible-light-driven photocatalyst: Changeable surface wettability

Abstract

To overcome one of the disadvantages of ultraviolet absorbance of the wide-bandgap semiconductor TiO2, visible-light-driven composite photocatalysts were fabricated through chemically bound conjugated polymers (CPs) on a TiO2 surface. The interfacial chemical bonding between TiO2 and the CP could act as a linker for close proximity of two species for easy transfer of the excited electrons from the CP to the conduction band of TiO2, which significantly enhanced the photocatalytic efficiency in the visible range. The robust covalent bond between the CP and TiO2 led to increased stability during photocatalysis, enabling repeated use after simple washing. Moreover, the hydrophilic surface of the photocatalyst could be fabricated by modifying the CP on the photocatalyst's surface. Such a wettability change of the photocatalyst's surface allowed the photocatalyst to be used in reduction and oxidation reactions with high efficiency in both water and organic solvents. The combination of the visible light-harvesting capacity of the CP and the photocatalytic activity of TiO2 enabled versatile uses of the composite photocatalysts.

Keywords

• Conjugated polymers
• TiO2
• Heterojunction
• Photocatalysis
• Surface wettability