Selective acetone gas sensing of Cu2(OH)3F/CuO enhanced by hydroxy bonds and fluorine substitution

Acetone gas in human breath could be examined in terms of biomarker applications for diagnosis of diabetes and detection of body fat decomposition. In this work, Cu2(OH)3F is hydrothermally synthesized and then pre-annealed in the interest of low ppm acetone gas-sensing. Cu2(OH)3F/CuO hierarchical structures were built after pre-annealing, and 250°C-annealed samples show the highest response of 23.6 toward 10 ppm acetone gas and 2.1 toward 400 ppb at operating temperature 200 ℃. Upon characterization for Cu2(OH)3F/CuO material properties, 250 ℃-annealed nanobranches show fluent hydroxy bonds, fluorine ion substitutions, and wide bandgap which could enhance the gas-sensing characteristics. The pre-annealing of Cu2(OH)3F between 200 ℃ and 350 ℃ was thoroughly characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), elemental analysis (EA) and thermal gravitational analysis (TGA) to analyze mechanism of the acetone gas-sensing behaviors.