Hydrothermal growth of highly oriented single crystalline Ta2O5 nanorod arrays and their conversion to Ta3N5 for efficient solar driven water splitting.

We grow vertically aligned single crystalline Ta2O5 nanorod arrays that can be converted to Ta3N5 nanorod arrays by nitridation. Combined with cobalt phosphate (Co-Pi) as a co-catalyst, such Ta3N5 nanorod photoanodes can yield photocurrent densities of ∼3.6 mA cm(-2) at 1.23 VRHE and ∼8.2 mA cm(-2) at 1.59 VRHE under AM 1.5G (100 mW cm(-2)) irradiation.