Black hollow TiO2 nanocubes: Advanced nanoarchitectures for efficient visible light photocatalytic applications

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 (⁓206 m2g−1), ultrathin shell (⁓50 nm), hydrogenated visible active structure and void nanoreactor-like space in the cubic structure. © 2018 Elsevier B.V.