Study on the sensing characteristics and hysteresis effect of the tin oxide pH electrode

Tin oxide thin films prepared by the radio frequency sputtering method were used as pH sensors based on the structure of the metal oxide electrode. The sensing characteristics and the hysteresis effect of the tin oxide pH electrode were studied. The hysteresis experiments were carried out under short- and long-loop circles, pH 7–4–7–10–7 and pH 7–2–7–12–6, respectively. Moreover, the hysteresis value was less than 7 mV in short-loop circle and the hysteresis value of pH 7 was 9 mV in acid side (HA) and 11 mV in alkali side (HB). The sensitivity of the tin oxide pH electrode was investigated between pH 2 and 12, whose pH sensitivity was about 59 mV/pH.