Photoelectrochemical Behavior of Nanoporous Oxide of FeNdB Alloy

Oxide nanoporous layer was synthesized by electrochemical anodization of commercially available sintered Fe14Nd2B permanent magnets. The anodized oxide layer consisted of predominantly alpha-Fe2O3 alloyed with Nd and B ions. The photoelectrochemical behavior of the anodic oxide was compared with thermally oxidized counterpart and the iron oxides obtained by anodization and thermal oxidation of pure iron foil. The oxide of FeNdB showed higher electron density of states, charge carrier density, and lower bandgap than the un-alloyed iron oxide. The catalytic activity of FeNdB oxide for the oxygen evolution reaction was slightly higher than that of the un-alloyed iron oxide. However, the photocatalytic behavior of the FeNdB oxide was inferior to the iron oxide, which could be attributed to the increased charge recombination and hole accumulation occurring at the FeNdB oxide surface. (C) 2015 The Electrochemical Society. All rights reserved.