Study of pH sensors based on TiO2 nanotubes

Abstract

TiO2 nanotube arrays obtained by Ti foil anodization are tested as pH electrodes, showing performance close to standard glass electrodes. The TiO2 nanotube arrays were obtained by Ti foil anodization in a NH4F organic solution with 20, 40 and 60 V and different anodization times. The obtained nanotubes samples were characterized by Scanning Electron Microscopy (SEM). Electrode modified by TiO2 nanotubes were characterized in pH buffer solution (pH of 4.0, 7.0 and 10.0) and the obtained results show that electrode modified by NTs obtained with anodization voltage of 40 V with 45 minutes presents an almost linear response close to Nernst equation (59 mV/pH).