The present work reports on the enhancement of TiO2 nanotubes photoelectrochemical water splitting rate by decorating the nanostructure with amino groups in a hydrothermal process using diethylenetriamine (DETA). The aminated TiO2 tubes show a stable improvement of the photoresponse in both UV and visible light spectrum and under optimized hydrothermal conditions, 4-fold increase of the photoelectrochemical water splitting rate is observed. From intensity modulated photocurrent spectroscopy (IMPS) and electrochemical impedance spectroscopy measurements (EIS), enhanced charge transfer is observed indicating a higher charge carrier density effect of the aminated nanotubes.