Tantalum oxide thin films for electrochemical pH sensor

Abstract

Present work demonstrates the fabrication and utilization of tantalum oxide (Ta _2 O _5 ) thin films as prominent pH sensing electrode material. Ta _2 O _5 film of 1 μ m thickness was deposited on glass substrates using physical vapor deposition technique. Structural and morphological studies were performed on these thin films. Electrochemical studies were carried out on these films using amperometry, linear sweep voltammetry and cyclic voltammetry techniques. These Ta _2 O _5 coated substrates were found to be sensitive to various assorted pH solutions and hence were used as pH sensing electrode. The performance of the electrode was studied in terms of stability, reusability and selectivity. Results reveal that the films were found to be suitable pH sensing material in 1.0–12.0 pH range. The sensing electrodes were found to be reliable and reusable with less than 5 s response time.

Keywords

• metal oxide
• physical vapor deposition
• pH sensing
• amperometry
• linear sweep voltammetry