3-D nanostructured tungsten-oxide gas-sensing film via anodizing sputter-deposited Al/W metal layers

The making of 3-D nanostructured metal oxide films is an active and competitive area of research, aiming at novel materials with enhanced properties and sensing devices with improved performances. Here we present the preparation procedure and gas sensing behavior of a novel self-assembled 3-D WO3 nanofilm that effectively combines the advantages of inorganic materials with the simplicity and universality offered by electrochemistry-based formation techniques. The film is formed mainly by electrochemical anodizing and is composed of an array of spatially-ordered upright-standing WO3 nanorods, assembled between the two noble metal patterned electrodes, which serve as direct semiconducting pathways for chemisorption reactions in a gas atmosphere. A test microsensor employing the nanofilm and assembled on a standard TO-8 Metal Can Package showed the fast and intensive response to H2, leaving more opportunities for further improvement of the active film configuration and sensor performance based on the computer-aided modelling and simulation results.