Renewable antimony-based pH sensor

Metal-based pH sensor has wide applications in industrial monitoring, soil environment, marine safety, and other fields. In this study, we proposed to renew the antimony-based sensor by physical polishing and electrochemical cathode reduction. Compared with before polishing, the pH response sensitivity after polishing increased from 0.034 V/pH to 0.042 V/pH, electrochemical cathode reduction renewed the pH response sensitivity improved from 0.018 V/pH to 0.032 V/pH (10 min) and 0.043 V/pH (30 min). The reasons for the deterioration of the pH response performance of the antimony-based sensor were analyzed by SEM, EDS, and XRD, and the renewable mechanisms of the sensor were proposed. The renewable effect of electrochemical cathode reduction on the degradation of sensor accuracy was evaluated for long-term monitoring. It is expected to realize remote online renewal of sensors under on-site unattended conditions, to reduce operation and maintenance costs of the sensor. These results provide solutions for the repeated regeneration of metal-based pH sensors which were degraded in performance and have significance for promoting the development and wide applications of renewable pH sensors.