Gas sensing properties of nanostructured bismuth oxychloride

In this work, nanostructured bismuth oxychloride (BiOCl) was prepared by a surfactant-assisted method. Bismuth trichloride and dioctyl sulfosuccinate (AOT) were dissolved in non-aqueous media, producing a fine precipitate. The calcination of the precipitated particles at 180 degrees C produced 3D hierarchical BiOCl semi-spherical architectures, assembled by microplates. The increase of the calcination temperature to 600 degrees C produced nanostructured ribbons, which are formed by the stacking of several BiOCl layers. Other microstructures can be formed at different calcination temperatures or by using other surfactants. Thick-films of the as-prepared BiOCl ribbons were made by its direct deposition on alumina substrates. The gas sensing characterization was performed at 300 and 400 degrees C using alternating current (AC). The tests gases were compressed air, CO, CO(2) and O(2). Humidity effects were discarded by using the extra dry version of these gases. At 300 degrees C. reproducible CO gas sensing patterns were obtained: however, the detection of CO(2) and O(2) produced unreliable results. At 400 degrees C, reliable gas sensing patterns were obtained in CO, CO(2) and O(2). According to its gas response, BiOCl behaved as a p-type seminconductor material. (C) 2011 Elsevier B.V. All rights reserved.