Templated synthesis of polyaniline nanotubes with Pd nanoparticles attached onto their inner walls and its catalytic activity on the reduction of p-nitroanilinum

In this paper, polyaniline (PANI) nanotubes with palladium nanoparticles (NPs) attached onto their inner walls were synthesized via a templating method which contains three steps. First, electrospun polystyrene (PS) nanofibers were coated with nearly monodispersed Pd NPs (d = 3.411 nm, σ = 0.687 nm, d is the average diameter of Pd NPs and σ is the standard deviation of their diameters) through in situ reduction of Pd²⁺ ions on the surface of sulfonated PS nanofibers. Then we used a self-assembly method to coat the composite with a PANI layer. The final product was obtained after the removal of PS nanofibers by diluting them in tetrahydrofuran. The morphology of samples was analyzed by scanning electron microscopy and transmission electron microscopy and the structure was characterized by Fourier transform infrared, ultraviolet–visible spectra, X-ray diffraction patterns and X-ray photoelectron spectroscopic patterns. Inductively coupled plasma atomic spectra were used to show the weight percentage of Pd nanoparticles. Its catalytic activity on the reduction of p-nitroanilinum was also investigated and compared to Pd/C catalyst and Pd/MWNTs.