Optimized FTO seeding enables the growth of high efficient Ta-doped TiO$_2$ nanorod photoanodes

Tantalum doped rutile nanorods were hydrothermally grown on FTO substrates using a new seeding approach. This approach allows the incorporation of high concentrations of up to 4.8 at% tantalum as active doping and results in a significant enhancement of photoelectrochemical water splitting rate (1.8 mA/cm2 at a potential of +1.5 V vs RHE) which corresponds to ca. 1% photocurrent conversion efficiency under AM 1.5, 100 mW/cm2 simulated sunlight irradiation.