Sandwich‐Nanostructured NiO–ZnO Nanowires@α‐Fe2O3 Film Photoanode with a Synergistic Effect and p–n Junction for Efficient Photoelectrochemical Water Splitting

Abstract

AbstractA new sandwich‐nanostructured film photoanode with synergistic effect and a p–n junction based on NiOZnO nanowires (NWs)@α‐Fe2O3 are synthesized for photoelectrochemical (PEC) water splitting. The sandwich‐nanostructured film photoanode is systematically characterized by scanning electron microscopy, X‐ray diffraction, transmission electron microscopy (TEM), and high‐resolution TEM. The PEC performances are characterized by the photocurrent densities versus potential curves, photocurrent densities versus time curves, and the incident photon to current efficiency curves. In addition, the sandwich‐nanostructured NiOZnO NWs@α‐Fe2O3 film photoanode shows significantly enhanced PEC performance compared with α‐Fe2O3 and ZnO NWs@α‐Fe2O3; this is mainly due to the synergistic effect and the construction of a p–n junction in NiOZnO NWs@α‐Fe2O3. Furthermore, the photoanode exhibits optimal PEC performance when the reacting concentration of nickel nitrate hexahydrate is 2.0 M.