Preparation of one-dimensional (1D) polyaniline–polypyrrole coaxial nanofibers and their application in gas sensor

A facile and low-cost method has been developed to prepare one-dimensional (1D) polyaniline–polypyrrole (PANI–PPy) coaxial nanofibers (PPCF). The morphology and molecular structure of PPCF were proved by scanning electron microscopy, transmission electron microscopy, EDX, UV–vis, FTIR and Raman spectroscopy. A possible synthetic scheme for the synthesis of PPCF has been proposed. The electrical responses of PPCF to triethylamine (TEA) vapor were measured at room temperature. It was found that PPCF showed a rapid, sensitive and reversible conductance change upon exposure to TEA vapor at concentrations ranging from 1 to 1000 ppm. The results suggested that the comprehensive performance of the gas sensor using PPCF was better than the results obtained using PANI nanofibers and PPy separately. In addition, a sensing mechanism was proposed.