Material design is one of the major driving forces to enhance the intrinsic light harvesting ability of a photocatalyst. Herein, the design of black TiO 2− x /Cu x O with chiral‐like structures where Pt single atom (SA) is successfully deposited on both black TiO 2− x and Cu x O for visible‐light H 2 generation is reported. Pt is well dispersed not only in the TiO 2− x surface but also at the surface of Cu x O, forming single‐atom alloys. Oxygen defects stabilize the Pt SAs deposition, which significantly enlarge the space charge layer, facilitating both the separation and transfer of photogenerated charge carriers. This structural optimization endows the black TiO 2− x /Cu x O/Pt film excellent light harvesting ability in the visible region, making it a promising visible‐light‐responsive photocatalyst. This work is expected to provide insights into the rational construction of nanostructured materials with chiral nematic structure exhibiting improved light harvesting ability.