Titania nanotube arrays for light sensor and UV photometer

Titania nanotube arrays were fabricated by anodic oxidation of titanium foil. The speed of electron transfer between the titania arrays and solution was measured by electrochemical impedance spectroscopy. High conductivity has been achieved by annealing the TNT arrays in air, much better than previously reported. The photocurrent performances in exposure to a simulated sunlight, tungsten lamp and fluorescent lamp have been investigated under 0 bias, indicating ∼ms response with advantages of high sensitivity and excellent heat stability. The device can effectively detect a trace UV light change and prevent from infrared/thermal influence in exposure to any light source containing UV, which promises a new type light sensor/switch for common light source including sunlight. In addition, the linear plot of photocurrent versus the incident light intensity (UV and simulated sunlight) indicates that the nanotube arrays can be used as a sensitive and stable UV photometer.