Arrayed porous iron-doped TiO2 as photoelectrocatalyst with controllable pore size

Arrayed porous iron-doped TiO2 with controllable pore size was prepared by using polystyrene spheres and its structure, morphology, composition and photoelectrochemical properties were characterized with X-ray diffraction, scanning electron microscope, inductively coupled plasma-atomic emission spectrometer and electrochemical methods. It is found that the photoelectrochemical properties of the arrayed porous TiO2 can be improved by doping adequate amount of iron in the lattice of TiO2 and the sample doped with 0.01 wt% Fe (based on Ti) exhibits the best photoelectrochemical performance. With doping 0.01 wt% Fe in TiO2, the photocurrent density of the sample is improved from 2.0 μA cm−2 to 10.0 μA cm−2 and its flat-band potential shifts from −0.38 V to −0.55 V (vs. SCE).

► Arrayed porous iron-doped TiO2.
► Photoelectrocatalyst for hydrogen generation.
► Pore size and iron content affect the photocatalytic activity.
► Smaller pore size is preferable for the activity improvement.
► Adequate content of iron is needed to reach a high activity.