Abstract: The present invention generally relates to materials that may be used to construct photoelectrodes. It more specifically relates to nanostructured metal oxide materials that may be used in photoelectrodes. In a composition aspect, the present invention provides a metal oxide film. The film ranges in thickness from 20 nm to 200 nm. There are at least 10 individual structures on the film surface within a 0.25 ?m2 area.

Abstract: The present invention provides a method for forming nano-structured iron oxide coatings on a substrate. The method includes the steps of: (a) subjecting a chamber containing a plasma source to vacuum; (b) feeding iron pentacarbonyl and O2 into a chamber containing a plasma source, wherein the O2 is fed into the chamber at a rate greater than that of the iron pentacarbonyl; (c) subjecting the substrate to the chamber, wherein the substrate is at a temperature less than 250° C., thereby forming an iron oxide coating on the substrate, wherein the iron oxide is greater than 90 percent in the ?-hematite form.

Abstract: The present invention generally relates to materials that may be used to construct photoelectrodes. It more specifically relates to nanostructured indium-doped iron oxide materials that may be used as photoanodes in photoelectrochemical cells which catalyze the splitting of water into its component gasses using sunlight as the energy source. In a composition aspect, the present invention provides an indium-doped iron oxide film. The film ranges in thickness from 20 nm to 200 nm, and has less than 10% indium by weight, less than 10% Fe2O3 and In2O3 by weight and less than 10% indium ferrate by weight. There are at least 10 disc-like structures on the film surface within a 0.25 ?m2 area, and the disc-like structures are roughly spherical in shape with a ratio of long dimension to short being at least 2:1. The radius of the disc-like structures ranges from 0.25 nm to 6 nm, and the disc-like structures are oriented at an angle between 20° and 160° relative to the film surface plane.

Abstract: The present invention provides a method for forming metal oxide coatings on a substrate. The method includes the steps of: (a) subjecting a chamber containing a plasma source to vacuum; (b) feeding metal oxide precursor and O2 into a chamber containing a plasma source, wherein the O2 is fed into the chamber at a rate greater than that of the metal oxide precursor; (c) subjecting the substrate to the chamber, wherein the substrate is at a temperature less than 250° C., thereby forming a metal oxide coating on the substrate.