Catalytic graphitization of polyacrylonitrile （PAN）-based carbon fibers with Fe-Cr2O3 composite coating

摘要

The process of electrodepositing Fe-Cr2O3 composite coating on polyacrylonitrile(PAN)-based carbon fibers and its catalytic graphitization were studied.Carbon fibers with and without electrodeposited Fe-Cr2O3 composite coating were heat treated at different temperatures and the structural changes were characterized by XRD,Raman spectroscopy and SEM.The results indicate that Fe-Cr2O3 composite coating exhibits a significant catalytic effect on graphitization of carbon fibers at low temperatures.When the Fe-Cr2O3-coated carbon fibers were heat treated at 1 300°C,the interlayer spacing(d002) and ratio of relative peak area(AD/AG) reach 3.364-and 0.34,respectively.Whereas,the extent of graphitization of pristine carbon fibers is comparatively low even after heat treatment at 2 800°C and the values of d002 and AD/AG are 3.414  and 0.68,respectively.The extent of graphitization of carbon fibers increases not only with the increase of the catalyst gross but also the Cr2O3 content in Fe-Cr2O3 coating.The catalytic effect of Fe-Cr2O3 composite coating accords with the dissolution  precipitation mechanism.