부산대학교 도서관

Self-organized and vertically oriented TiO2nanotubes (TNTs) were synthesized via anodization of Ti sheet in a glycerolbasedused electrolyte. Graphite (Gt) is doped in TNTs by physical vapor deposition (PVD) under Ar-atmosphere at 700 °Cusing polyvinyl alcohol (PVA) as a precursor. The samples were characterized using FESEM, HRTEM, XRD, Raman,XPS, and UV–vis diffuse reflectance spectroscopy. HRTEM, XRD, and Raman analysis confirm the suppression of phasetransformation from anatase to rutile due to Gt doping. The UV–vis absorption properties and photocatalytic activity of thepristine and Gt-doped TNTs have been investigated. The bandgap absorption edge of Gt-doped TNTs shifts towards a higherwavelength (~ 550 nm) compared to the pristine TNTs (~ 390 nm). Moreover, the Gt-doped TNTs show strong absorptionin the visible region. This makes it a good candidate for energy-storing applications. It has been found that Gt-doped TNTsdisplay two-fold enhanced photocatalytic activity for methyl orange (MO) degradation compared to pristine. The enhancedphoto-degradation of Gt-doped TNTs is ascribed to the higher absorptivity, better crystallinity, and lower bandgap of TNTsdue to Gt doping. The enhanced photo-degradation ability of Gt-doped TNTs can be used to clean industrial wastewater.