Cerium-Doped Iron Oxide Nanorod Arrays for Photoelectrochemical Water Splitting.

In this work, a simple one-step hydrothermal method was employed to prepare the Ce-doped FeO ordered nanorod arrays (CFT). The Ce doping successfully narrowed the band gap of FeO, which improved the visible light absorption performance. In addition, with the help of Ce doping, the recombination of electron/hole pairs was significantly inhibited. The external voltage will make the performance of the Ce-doped sample better. Therefore, the Ce-doped FeO has reached superior photoelectrochemical (PEC) performance with a high photocurrent density of 1.47 mA/cm at 1.6 V vs. RHE (Reversible Hydrogen Electrode), which is 7.3 times higher than that of pristine FeO nanorod arrays (FT). The Hydrogen (H) production from PEC water splitting of FeO was highly improved by Ce doping to achieve an evolution rate of 21 μmol/cm/h.