Synthesis of polypyrrole/Fe-kanemite nanocomposite through in situ polymerization: effect of iron exchange, acid treatment, and CO2 adsorption properties
文摘
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 °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 °C, while the PPy/Fe-kan (5%) nanocomposite presented the best CO2 adsorption capacity around 1.7 mmol g−1 at 0 °C under low pressure that is mainly attributable to physical adsorption.