  The present work reports on the enhancement of TiO2 nanotubes
photoelectrochemical water splitting rate by decorating the nanostructure with
an amine layer in a hydrothermal process using diethylenetriamine (DETA). The
aminate coated TiO2 tubes show a stable improvement of the photoresponse in
both UV and visible light spectrum and under hydrothermal conditions, 4-fold
increase of the photoelectrochemical water splitting rate is observed. From
intensity modulated photocurrent spectroscopy (IMPS) measurements significantly
faster electron transport times are observed indicating a surface passivating
effect of the N-decoration.
