Black hollow nanocubic TiO2 (BHC-TiO2) architectures have been synthesized via multi-step approach comprising co-precipitation to prepare hematite nanocubes; titania covering of hematite towards Fe2O3/TiO2 core/shell nanocubes and hydrothermal hematite etching process to yield hollow cubic TiO2 structures with Ti3+ species after high temperature hydrogen treatment. The resultant BHC-TiO2 nanoarchitectures exhibited excelling photocatalytic performance under visible light in the preparation of benzimidazole derivatives. This superior activity can be attributed to the design of BHC-TiO2 with high surface area (similar to 206 m(2)g(-1)), ultrathin shell (similar to 50 nm), hydrogenated visible active structure and void nanoreactor-like space in the cubic structure.