A novel Au@TNT catalyst, with gold nano-particles (NPs) entrapped in TiO2 nanotube (TNT), was prepared by a vacuum assisted-impregnation route. For the photocatalytic water splitting under visible light, the Au@TNT catalyst presented 2 times higher activity than the Au/TNT with most part of gold NPs on the outer surface of TNT. The enhanced activity can be ascribed to the confinement of TNT which can effectively decreases the particle size and modulates the electronic state of gold catalyst. [GRAPHICS] .