Structural characterization and gas sensing property of Cd-doped SnO2 nanocrystallites synthesized by mechanochemical reaction

A series of Cd-doped SnO2 nanocrystallites have been successfully synthesized by mechanochemical reaction. The as-synthesized samples were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The effect of Cd-doped amount on the crystalline structure, crystallite sizes, lattice parameter, surface morphology and elements chemical state of the SnO2 nanocrystallites has been discussed. The sensing property of the Cd-doped SnO2 nanocrystallites have enhanced evidently compared with that of the SnO2. The 10 wt% Cd-doped SnO2 based sensor shows an excellent sensing performance, such as high response (276.9 for 1000 ppm C2H5OH), a rapid response time (within 5 s for 90% response and recovery times) and high selectivity to ethanol (the selective coefficient Kethanol/butane achieves 37).