A simple route for the preparation of nanostructured GdCoO3 via the solution method, as well as its characterization and its response to certain gases

This work presents the synthesis of perovskite GdCoO3 by a microwave-assisted solution method in order to test its possible application as a gas sensor. The crystal evolution, structure, composition, texture, morphology, and particle size were analyzed by X-ray diffraction, scanning and transmission electron microscopies, and nitrogen physisorption. Our synthesis route allowed to obtain GdCoO3 at lower temperatures and shorter reaction times than conventional methods. Measurements confirmed the formation of porous GdCoO3 microbases with a thickness of 7-13 mu m. The GdCoO3 microbases were constituted by nanoparticles of size 10-20 nm. Additionally, crystallites of size 85-130 nm were observed distributed on the surface of the microbases, covering a surface area of around 19 m(2)/g. Pellets elaborated from GdCoO3 powders were tested as sensors in carbon monoxide and propane gaseous atmospheres at different temperatures and gas concentrations. The GdCoO3 showed a good performance as a gas sensor compared to other similar oxides. The oxide was clearly sensitive to the studied gases even at concentrations as low as 5 ppm at a temperature of 100 degrees C. The response of the material was homogeneous and increased with both the increase in temperature and gas concentration.