Photoelectrochemistry of Pure and Core/Sheath Nanowire Arrays of Cu[sub 2]S Directly Grown on Copper Electrodes

Photoelectrochemistry (PEC) of straight and isolated nanowires arrayed on a copper foil is studied. A cathodic photocurrent is observed, which increases with the increasing negative bias of the film electrode, conforming to the p-type semiconducting nature of PEC studies on the core/sheath nanowires of nanowires coated with other nanoparticles such as CdS, polypyrrole, and Au) have revealed distinctly different characteristics. nanowires exhibit a slightly higher photocurrent response due to the charge transfer between the p-type core and n-type CdS sheath, whereas the photocurrent response obtained for nanowires is generally an order of magnitude smaller than that for pure nanowires under the same bias voltage. For nanowires, however, Au nanoparticles can readily accept the photogenerated electrons from the conduction band of this redirects the electron transfer pathway and results in the anodic photocurrent response. On the basis of these findings, different photocurrent generation mechanisms are proposed. © 2005 The Electrochemical Society. All rights reserved.