pH sensors based in TiO2 NTs arrays

pH sensor fabricated with TiO
₂
nanotube arrays with diameter and length controlled by the anodization voltage and time were obtained and characterized. The TiO
₂
nanotube arrays were obtained by Ti foil anodization in a NH4F organic solution with 20 and 40 V for 5, 15 and 25 min. pH sensors based on Ti
₂
NTs electrodes presented linear response respect to the pH value in the 4-10 pH range. The pH sensor with nanotubes obtained with 20V / 25 min presents a reproducible response and the best sensitivity value, 45.8 mV/pH. This TiO
₂
NTs pH sensor irradiated by UV shows a very stable response and a sensitivity value of 50.9 mV/pH close to Nernst equation (59 mV/pH).