Surface modification of α-Fe ₂O ₃ nanorod array photoanodes for improved light-induced water splitting

α-Fe ₂O ₃ nanorod arrays were fabricated by a low-temperature aqueous chemical growth (ACG) technique and followed by an annealing process. For the surface doping of α-Fe ₂O ₃ nanorods, β-FeOOH nanorods obtained via ACG were coated with a thin layer of Cr ³⁺ precursor solution by spin coating, and then underwent the annealing treatment in air. Conducting polymer polypyrrole (PPy) decorated α-Fe ₂O ₃ nanorods were prepared by electrodeposition method using malic acid contained pyrrole aqueous solution. Primary results showed that the photocurrents of α-Fe ₂O ₃ nanorod array photoanodes were greatly enhanced by surface doping of Cr ³⁺, as well as PPy decoration. This might be due to the retarded charge recombination and promoted surface reaction rate of photogenerated holes with water. Further investigation on surface modification of α-Fe ₂O ₃ nanorod array photoanodes is currently conducted in our group.