Synthesis of polypyrrole/Fe-kanemite nanocomposite through in situ polymerization: effect of iron exchange, acid treatment, and CO2 adsorption properties

This paper focuses on the synthesis of polypyrrole/Fe-kanemite nanocomposites by in situ polymerization of pyrrole. Different percentages of PPy/Fe-kan have been prepared and tested for the CO2 adsorption. Fe-exchanged kanemite was prepared using various iron contents and used as an oxidant for the preparation of PPy/Fe-kan nanocomposite. The obtained materials were characterized using various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy, ultraviolet-visible (UV-vis), thermogravimetric analysis TGA, energy dispersive X-ray analysis, scanning and transmission electronic microscopy (SEM, TEM). Based on the XRD and UV-vis analysis, the exchange process leads to the formation of various iron species on the external and internal surface. The thermal stability of PPy/Fe-kan was improved and increased in the following order PPy/Fe-kan (1%) > PPy/Fe-kan (3%) > PPy/Fe-kan (5%) > PPy/Fe-kan (10%) > PPy. SEM and TEM analysis show that the nanocomposite particles have spherical morphology with a high dispersion of the Fe-kanemite in the polymer matrix. CO2 adsorption at 0 and 15 A degrees C was carried using a volumetric method, and the recorded isotherm indicated that the CO2 adsorption capacity of PPy/Fe-kan can be enhanced through modification by polypyrrole. The unmodified Na-kanemite has low CO2 adsorption capacity around 0.05 mmol g(-1) at 15 A degrees C, while the PPy/Fe-kan (5%) nanocomposite presented the best CO2 adsorption capacity around 1.7 mmol g(-1) at 0 A degrees C under low pressure that is mainly attributable to physical adsorption.