  Formaldehyde is a ubiquitous and high toxicity gas. It is an essential task
to efficient detect owing to their toxicity and diffusion. In this work, we
studied on the detection of trace amount of formaldehyde based on hollow Co3O4
nanostructure. It is found that Co3O4 hollow spheres with different structures
shows distinct sensing performance towards formaldehyde at room temperature,
the response value of nanosheet modified Co3O4 towards 100 ppm formaldehyde
will reach 35 in 18 second, and the nanoparticle modified Co3O4 hollow sphere
will reach 2.1 in 18 second, 17 in 300 second. The nanosheet modified and
nanoparticle modified Co3O4 hollow sphere will reach 4 and 20 in 10 second
towards 100 ppm formaldehyde at room temperature. As room temperature, the
sensors do not response towards NH3, CO, etc. The sensing mechanism was
proposed based on the theoretical and experimental results. The Co3O4 sensor
shows that potential utility in CH2O quick sensing at room temperature.
