Hierarchical Fe2O3 nanorods/TiO2 nanosheets heterostructure: Growth mechanism, enhanced visible-light photocatalytic and photoelectrochemical performances

A novel three-dimensional (3D) Fe2O3 nanorods (NRs)/TiO2 nanosheets (NSs) heterostructure is fabricated by employing the TiO2 NSs with dominant high-energy {0 0 1} facets as synthetic template via the facile hydrothermal and chemical bath deposition methods. The structure, morphology and optical property of 3D Fe2O3/TiO2 composites are examined, and the results demonstrate that these samples have pure phase, high crystallinity and good visible-light response. Furthermore, all Fe2O3/TiO2 composites exhibit the superior photocatalytic and photoelectrochemical (PEC) performances compared to pure TiO2 NSs, which should be ascribed to the larger surface area, better optical absorption and efficient electron-hole separation of 3D Fe2O3/TiO2 heterostructure. Among Fe2O3/TiO2 composites, the sample T3 obtained by using 0.05 M iron nitrate at 90 °C for 100 min exhibited the best visible-light photocatalytic activity and PEC performance, which achieves 89.3% photodegradation of Methyl Blue within 120 min and 2.39 mA cm−2 photocurrent density at a potential of 0 V, respectively. The photocatalytic degradation efficiency and photocurrent density of T3 are 1.83 and 11.95 times higher than that of pure TiO2 NSs. In addition, the detailed growth mechanism of Fe2O3 nanomaterials onto TiO2 NSs and the optimization mechanism of photocatalytic and PEC performances are also discussed in present paper.