Facile wet chemical synthesis of Al doped CuO nanoleaves for carbon monoxide gas sensor applications

Abstract

pure and Al doped CuO nanostructures were synthesized by a facile co-precipitation method and used for fabrication of highly sensitive, low cost and low temperature carbon monoxide (CO) gas sensors. Gas responses of the fabricated sensors were measured for different CO concentrations (35−12500ppm) and at different temperatures(70°−230°C). The crystalline structure, morphology, surface area and elemental composition of the prepared nanostructures were characterized by XRD, FE-SEM, TEM, BET, EDX and Mapping analyses. Our results indicated that Al doping has increased the response of CuO nanostructures to CO. The improving effect of Al dopant for CuO nanostructures was discussed through the morphological change and increase of the surface area of CuO nanostructures. FESEM analysis has shown that Al dopant has restricted growth of CuO nanostructure in three dimensions and led to formation of two dimensional nanoleaves with larger effective surface area for adsorption of gas molecules and therefore higher response to CO. At the optimum operating temperature, the maximum response to 800 ppm CO for Al doped CuO nanoleaves is within 20% larger than the maximum response for pure CuO nanostructures.