Controlled growth of vertically oriented hematite/Pt composite nanorod arrays: use for photoelectrochemical water splitting

Highly ordered and vertically grown Pt-doped alpha-Fe2O3 nanorod arrays on a gold substrate were successfully prepared by the electrochemical co-deposition method using an anodized aluminum oxide template. The effect of the Pt doping in alpha-Fe2O3 nanorod arrays on their water splitting ability was investigated for the first time. The elemental maps obtained by energy dispersive spectroscopy showed that the Pt was uniformly dispersed in the alpha-Fe2O3 nanorod arrays. The photoelectrochemical properties of the alpha-Fe2O3/Pt composite nanorod arrays as a function of the Pt content were studied by measuring their photocurrent-potential behavior in 1 M NaOH electrolyte under AM 1.5 100 mW cm(-2) illumination. The Pt-doped a-Fe2O3 nanorod arrays show an improvement in solar-to-hydrogen conversion efficiency (similar to 5%) for photoelectrochemical water splitting compared to undoped samples. To the best of our knowledge, it is the highest value yet obtained from alpha-Fe2O3.