Gas Sensing Properties of Co₃O₄-Doped Bismuth Oxychloride Nanowires and Nanoribbons

Abstract

Co 3 O 4 -doped bismuth oxychloride (BiOCl) nanowires and nanoribbons were prepared by a surfactant-assisted method. Bismuth trichloride, cobalt nitrate and polyvinyl pyrrolidone were used as reagents. The calcination of the precursor material at 600ºC produced a Co 3 O 4 -BiOCl composite, which was characterized by X-ray powder diffraction. Nanowires and nanoribbons were identified by scanning and transmission electron microscopies. The length of them was in the range of 50 to 600 μm, with a cross section size between 50 nm and 15 μm. Thick-films of the asprepared powders were tested as CO 2 gas sensors. The Co 3 O 4 -BiOCl composite sensor device behaves as a p-type semiconductor material, having variations of |Z| of ~2.2 MΩ, at 200ºC. A uniform and reproducible CO 2 gas response pattern was obtained, suggesting this material as an alternative gas sensor.