  In this work we introduce the use of TiN/Ti2 N layers as a back contact for
lifted-off membranes of anodic Ta3N5 nanotube layers. In photoelectrochemical
H2 generation experiments under simulated AM 1.5G light, shift of the onset
potential for anodic photocurrents to lower potentials is observed, as well as
a higher magnitude of the photocurrents compared to conventional Ta3N5
nanotubes (~ 0.5 V RHE ). We ascribe this beneficial effect to the improved
conductive properties of the TiNx -based back contact layer that enables a
facilitated electron-transport for tantalum-nitride based materials to the
conductive substrate.
