The Design And Application About Reactive Formaldehyde Sensor Based On Carbon Nanotubes

A reactive formaldehyde sensor based on carbon nanotubes has been designed and prepared first in this paper. Carbon nanotubes were modified with amino group by the reaction which produced Schiff base between amine and aldehyde, then they were used to prepare sensitive film electrodes combined with Nafion to detect low concentration of formaldehyde. Two kinds of amino groups (the length of carbon chain is 2 and 6) were respectively grafted onto carbon nanotubes with different extent of grafting. And the technological conditions of sensitive film electrodes combined with Nafion was studied. Compared to physical adsorption materials, the results showed that the aforementioned material behaved higher sensitivity and selectivity to formaldehyde, and the more grafted ratio, the better response. The minimum detectable concentration of formaldehyde liquid and formaldehyde gas were lppm and 20ppb, respectively. It has been proved that this kind of sensor can detect microscale formaldehyde and has significant practical value.