A selective room temperature formaldehyde gas sensor using TiO2 nanotube arrays

A new gas sensor using TiO2 nanotube arrays was fabricated and explored for formaldehyde detection at room temperature. Highly ordered vertically grown TiO2 nanotube arrays were synthesized by using the conventional electrochemical anodization process. The sensor using the fabricated nanotube arrays as the sensing elements demonstrated a good response to different concentrations of formaldehyde from 10 to 50 ppm and a very good selectivity over other reducing gas species such as ethanol and ammonia at room temperature. While the exact sensing mechanism is unclear, some possibilities are briefly discussed.