The TiO2 NTs were first treated with bi-functional mercaptoacetic acid linkers (HOOC–R–S). The –OH group on the surface of TiO2 NT provides a strong affinity with the carboxylate group in the linker molecules. The thiol functional group in the linker molecules facilitates the binding with Ag from AgNO3 solution. After Ag+ ions were reduced by NaBH4, Ag nanoparticles formed by nucleation and growth. Display omitted ► Ag nanoparticles with an average diameter of 9.2nm were filled in the TiO2 nanotubes by a successive ionic layer adsorption and reaction (SILAR) technique. ► Bi-functional mercaptoacetic acid linkers were used to bind TiO2 nanotubes with Ag nanoparticles. ► Ag nanoparticles modification of TiO2 NTs largely enhanced the photocatalytic degradation of methyl orange under ultraviolet light irradiation. Ordered anatase TiO2 nanotubes (TiO2 NTs) on Ti substrate were synthesized by electrochemical anodization and subsequently vapor-thermal treatment. Ag nanoparticles were decorated on TiO2 NTs by successive ionic layer adsorption and reaction (SILAR) technique. Raman spectroscopy, X-ray absorption near edge spectroscopy (XANES), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for the characterization of surface morphology, phase composition, and microstructure of the original TiO2 NTs, the vapor-thermally treated TiO2 NTs and the Ag nanoparticles decorated TiO2 NTs. The results indicate that vapor-thermal treatment favors to the transformation of amorphous TiO2 into anatase phase. Increasing the SILAR cycle times favors to increase the loaded amounts of Ag nanoparticles in TiO2 NTs. Ag nanoparticles are uniformly distributed in the TiO2 NTs, and the SILAR process does not damage the ordered tubular structure. A possible formation mechanism of Ag/TiO2 NTs has also been proposed. The photocatalytic results showed that the Ag nanoparticle modified TiO2 NTs largely enhanced the photocatalytic degradation of methyl orange under ultraviolet light irradiation.