LbL Fabricated PU/PSS/{201}TiO 2 Multilayer Thin Films with Exposed High-Index {201} Facet for Environmental Applications

Titanium dioxide (TiO 2 ), as the most widely used semiconductor photocatalyst, still suffers from low quantum efficiency, easy agglomeration, and difficult separation, which limits the practical application. In this study, high-index {201}TiO 2 was prepared with a dandelion-like lamellar structure through the control of hydrofluoric acid (HF), and then, the (PU/PSS/TiO 2 ), (PU/PSS/{201}TiO 2 ) hybrid films were prepared by layer-by-layer (LbL) self-assembly technique. Polyurethane (PU) and sodium polystyrene sulfonate (PSS) were used as a substrate for the immobilization of TiO 2 . The photocatalytic activity and reusability of the hybrid films were investigated with experiments of photocatalytic degradation of methyl blue (MB). These results indicate that the (PU/PSS/{201}TiO 2 ) n hybrid films had superior photocatalytic degradation performance relative to (PU/PSS/TiO 2 ) n and TiO 2 , and the photocatalytic activity of the film could be repeatedly used for up to six times reuse. In addition, the corresponding mechanism of enhanced photocatalytic activity was proposed on the basis of the investigated results from reactive species scavenging of (PU/PSS/{201}TiO 2 ) 10 . The active species h + played the most important role in the photocatalytic reaction. This work may develop one kind of high-index {201}TiO 2 thin by LbL self-assembly, making the photocatalyst a promising candidate in wastewater treatment application. Graphical Abstract