文摘
Highly sensitive and selective toluene sensors based on ordered mesoporous Co3O4 have been successfully developed. The combined characterizations of X-ray diffraction (XRD) patterns, nitrogen adsorption-desorption isothermal, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicate that mesoporous Co3O4 with ordered mesoporous structure and high surface area has been successfully prepared by the nanocasting method using mesoporous silica (SBA-15) as hard template and Co(NO3)2路6H2O as cobalt source. It is also found that mesoporous Co3O4 thus obtained shows good response toward toluene with the concentrations ranging from 1 ppm to 1000 ppm. Furthermore, mesoporous Co3O4 also exhibits high selectivity for detection of toluene, compared to other interferences, such as ethanol, formaldehyde, ethanol, acetone, methanol and ammonia. Most importantly, mesoporous Co3O4 exhibits better sensing performance than that of non-porous Co3O4 obtained by direct calcination of Co(NO3)2路6H2O in the absence of any templates, which can be attributed to unique properties of mesopotous Co3O4, such as high surface area, open mesoporous structure as well as relatively small crystal size.
