Effect of surface overlayer in enhancing the photoelectrochemical water oxidation of in situ grown one-dimensional spinel zinc ferrite nanorods directly onto the substrate.

Overlayer passivation minimizes surface defects and arrests the back transfer of electrons for an enhanced charge extraction. Surface passivation of ZnFe2O4 using alumina yields enhanced charge carrier density from 8.43 × 1020 cm-3 to 18.83 × 1020 cm-3 giving a record efficiency in this class of compounds.