A method is provided for forming iridium oxide (IrOx) nanotubes. The method comprises: providing a substrate; introducing a (methylcyclopentadienyl)(1,5-cyclooctadiene)iridium(I) precursor; introducing oxygen as a precursor reaction gas; establishing a final pressure in the range of 1 to 50 Torr; establishing a substrate, or chamber temperature in the range of 200 to 500 degrees C.; and using a metalorganic chemical vapor deposition (MOCVD) process, growing IrOx hollow nanotubes from the substrate surface. Typically, the (methylcyclopentadienyl)(1,5-cyclooctadiene)iridium(I) precursor is initially heated in an ampule to a first temperature in the range of 60 to 90 degrees C., and the first temperature is maintained in the transport line introducing the precursor. The precursor may be mixed with an inert carrier gas such as Ar, or the oxygen precursor reaction gas may be used as the carrier.