Templated Electrodeposition and Photocatalytic Activity of Cuprous Oxide Nanorod Arrays

Cuprous
oxide (Cu2O) nanorod arrays have been prepared via a novel
templated electrodeposition process and were characterized for their
photocatalytic behavior in nonaqueous photoelectrochemical cells.
Zinc oxide (ZnO) nanorod films serve as sacrificial templates for
the in situ formation of polymer nanopore membranes on transparent
conductive oxide substrates. Nitrocellulose and poly­(lactic acid)
are effective membrane-forming polymers that exhibit different modes
of template formation, with nitrocellulose forming conformal coatings
on the ZnO surface while poly­(lactic acid) acts as an amorphous pore-filling
material. Robust template formation is sensitive to the seeding method
used to prepare the precursor ZnO nanorod films. Photoelectrochemical
cells prepared from electrodeposited Cu2O films using
methyl viologen as a redox shuttle in acetonitrile electrolyte exhibit
significant charge recombination that can be partially suppressed
by a combination of surface passivation methods. Surface-passivated
nanostructured Cu2O films show enhanced photocurrent relative
to planar electrodeposited Cu2O films of similar thickness.
We have obtained the highest photocurrent ever reported for electrodeposited
Cu2O in a nonaqueous photoelectrochemical cell.