Synthesis of polypyrrole nano-fibers with hierarchical structure and its adsorption property of Acid Red G from aqueous solution

The polypyrrole nano-fibers with hierarchical structure were synthesized in α-CD/I₂ inclusion compound solution via chemical oxidation by using FeCl₃ as the oxidant. The formation of the hierarchical structured PPy was certified by Field Emission Scanning Electronic Microscope (SEM). Fourier transform infrared spectroscopy (FT-IR) results showed that the molecular structure of the prepared PPy backbone is same as the conventional PPy. From the results of X-ray fluorescence spectrometer (XRF) and X-ray diffraction (XRD) measurements, the α-CD/I₂-Fe²⁺ is as the soft-template during the synthesis process of PPy with hierarchical structure. Some I^- ions retained in the backbone of the prepared PPy were as the counter ion after rinse. PPy with hierarchical structure shows very good adsorption performance for the Acid Red G (azo dye). The adsorption equilibrium time was very short (within 30 min) and the maximum adsorption capacity (Q_max) was 121.95 mg/g, which is better than that of some other adsorbents reported in literatures. The hierarchical structured PPy that we prepared can be considered as a potential adsorbent for the removal of organic dyes from wastewater.