Fabrication and enhanced visible-light photoelectrochemical performance of periodic hierarchical 3D Ti-Fe-O structure

A novel hierarchical 3D Ti-Fe-O nanorings/nanotube structure (H-Ti-Fe-O NN) has been fabricated by in situ multi-stepped anodization, which exhibited obviously enhanced visible-light photoelectrochemical (PEC) activity. This performance was benefited from the unique 3D structure that the upper nanoring layer provided visible-light trapping capability by multiple light reflection/scattering and bottom nanotube array provided the improved carrier mobility. In addition, the heterojunction of Fe2O3 and TiO2 further contributed to the effective charge separation.