PbS-modified TiO 2 heterostructure nanotube arrays (NAs) were synthesised by successive ionic layer adsorption and the reaction method. Ultrasound (PbS(u)/TiO 2 NAs) has an important function in the formation of PbS nanoparticles. Compared with non-ultrasound PbS/TiO 2 NAs, PbS(u)/TiO 2 NAs have small PbS nanoparticles uniformly distributed on both the outside and inside rather than the top surface of TiO 2 NAs. The average size of the PbS nanoparticles in PbS(u)/TiO 2 NAs ranges from 10 to 15nm. PbS/TiO 2 NAs and PbS(u)/TiO 2 NAs both exhibit high absorption in the 300–1000nm region. Moreover, a stronger separate efficiency of photogenerated charge carriers is found in PbS(u)/TiO 2 NAs than that in PbS/TiO 2 NAs.