Patent ID: 8148188

Claim:
A method for manufacturing a stable electrode for a photoelectrochemical cell, the method comprising: providing a semiconductor layer, wherein the semiconductor layer is configured to function as an electrode of a photoelectrochemical cell, wherein the semiconductor layer comprises an unstable semiconductor material subject to at least one of oxidation, passivation, or decomposition when exposed to a wet environment; providing catalyst particles on a surface of the semiconductor layer that is free from oxidation, passivation, and decomposition; and thereafter using the catalyst particles to grow a dense mat of carbon nanotubes directly on the surface, wherein the dense mat of carbon nanotubes forms a hydrophobic protection barrier on the surface, wherein the hydrophobic protection barrier is configured to keep electrolyte and water away from the surface so as to avoid oxidation, passivation or decomposition of the semiconductor layer beneath the carbon nanotubes of the dense mat, whereby a stable electrode for a photoelectrochemical cell is obtained, wherein the stable electrode comprises the semiconductor layer and the dense mat of carbon nanotubes, and wherein the dense mat of carbon nanotubes is selected from the group consisting of a dense mat of straight and aligned carbon nanotubes having a density on the surface of from about 10 10 tubes per cm 2 to about 10 13 tubes per cm 2 and a dense mat of curled and twisted carbon nanotubes having a density on the surface of from about 10 8 tubes per cm 2 to about 10 11 tubes per cm 2 .