Two-dimensional (2D) ultrathin MoS2-modified black Ti3+-TiO2 nanotubes were fabricated using an electrospinning-hydrothermal treatment-reduction method.Bare TiO2 nanotubes were fabricated via electrospinning.Then,2D MoS2 lamellae were grown on the surface of the nanotubes and Ti3+/Ov ions were introduced by reduction.The photocatalytic performance of the 2D MoS2/Ti3+-TiO2 nanotubes was ～15 times better than that of TiO2.The HER enhancement of the MoS2/Ti3+-TiO2 nanotubes can be attributed to the Pt-like behavior of 2D MoS2 and the presence of Ti3+ ions,which facilitated the quick diffusion of the photogenerated electrons to water,reducing the H2 activation barrier.The presence of Ov ions in the nanotubes and their hollow structure increased their solar utilization.