Study of pH sensors based on TiO2 nanotubes

TiO
₂
nanotube arrays obtained by Ti foil anodization are tested as pH electrodes, showing performance close to standard glass electrodes. The TiO
₂
nanotube arrays were obtained by Ti foil anodization in a NH
₄
F 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 TiO
₂
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).