Preparation of porous flower-like CuO/ZnO nanostructures and analysis of their gas-sensing property

Porous flower-like CuO/ZnO nanostructures were obtained using a facile chemical solution method combined with subsequent calcination. The calcination of the precursors produced flower-like CuO/ZnO nanostructures, which is comprised of interconnected highly porous CuO/ZnO nanosheets that resulted from the thermal decomposition of the as-prepared precursors, i.e., flower-like zinc copper hydroxide carbonate. Moreover, the nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, thermogravimetric-differential thermal analysis, and Brunauer-Emmett-Teller N2 adsorption-desorption analyses, among others. The BET surface area of the hierarchically porous CuO/ZnO nanostructures was calculated at 17.1 m2 g−1. Furthermore, the gas sensing properties of the as-prepared porous flower-like CuO/ZnO nanostructures were investigated using volatile organic compounds. Compared with the porous flower-like ZnO nanostructures, the porous flower-like CuO/ZnO nanostructures exhibited a higher response and lower working temperature with certain organic vapors, such as ethanol, acetone, and formaldehyde. The responses to 100 ppm ethanol and formaldehyde were 25.5 and 28.9, respectively, at a working temperature of 220 °C. These results showed that the porous flower-like CuO/ZnO nanostructures are highly promising candidates gas sensing applications.