The Effect of a Metallic Ni Core on Charge Dynamics in CdS-Sensitized p-Type NiO Nanowire Mesh Photocathodes

We report on the synthesis and photoelectrochemical characterization of photocathodes based on CdS-sensitized Ni-NiO core-shell nanowire mesh inverse opals (IOs). Compared to the NiO-CdS nanowire mesh IO electrode, the hole diffusion coefficient of the CdS-sensitized Ni-NiO core-shell nanowire mesh IO photocathode was one order of magnitude larger, indicating that the Ni core facilitated hole transfer in nanostructured p-type electrodes. As a result, the charge-collection efficiency of the Ni-NiO core-shell nanowire mesh IO electrode was shown to be essentially 100%.