The Ti wire functionalized with inherent TiO2 nanotubes by anodization as one-electrode gas sensor: A proof-of-concept study

Abstract

We propose a Ti wire functionalized with inherent anatase TiO2 nanotubes by an anodization process to serve as a one-electrode gas sensor. The design is similar to other known one-electrode gas sensors when the wire is employed both as a heater and measuring resistive element. We discuss the low-cost fabrication protocol, the structure of the sensor characterized by Raman spectroscopy and electron microscopy, and show the proof-of-concept sensor responses to a few organic vapors, acetone and alcohols, in mixture with air. We have found the response-to-concentration curves to follow a linear fit with a detection limit below 1000 ppm. These findings enlarge the range of possible gas sensor architectures based on nanostructured material for research and practical applications.