聚丙烯腈基炭纤维表面电沉积 Ni-Fe合金的催化石墨化性能

摘要

在聚丙烯氰基炭纤维上电沉积Ni-Fe合金催化剂,并采用x-射线衍射和拉曼光谱方法考察其对热处理炭纤维石墨化的催化性能.结果表明:Ni-Fe合金在低温条件下对炭纤维石墨化有着优异的催化性能.附有Ni-Fe合金(铁的质量分数为57.91%)的聚丙烯腈基炭纤维经过1250℃热处理后其石墨化度为69.0%,而空白样炭纤维经过2800℃热处理后其石墨化度仅为30.1%.在相同温度下,Ni-Fe合金对碳纤维石墨化的催化性能优于纯铁和纯镍的,这表明Ni和Fe元素之间存在协同催化作用.同时,研究表明Ni-Fe合金对石墨化的催化遵循溶解再析出机理.%Ni-Fe alloy was electrodeposited on the surface of polyacrylonitrile (PAN)-based carbon fibers,and catalytic graphitization effect of the heat-treated carbon fibers was investigated by X-ray diffractometry and Raman spectra. It is found that Ni-Fe alloy exhibits significant catalytic effect on the graphitization of the carbon fibers at low temperatures. The degree of graphitization of the carbon fibers coated with Ni-Fe alloy (57.91% Fe,mass fraction) reaches 69.0% through heat treatment at 1 250℃. However,the degree of graphitization of the carbon fibers without Ni-Fe alloy is only 30.1% after being heat-treated at 2 800 ℃.The catalytic effect of Ni-Fe alloy on graphitization of carbon fibers is better than that of Ni or Fe at the same temperature,indicating that Ni and Fe elements have synergic catalytic function. Furthermore,Fe content in the Ni-Fe alloy also influences catalytic effect.The catalytic graphitization of Ni-Fe alloy follows the dissolution-precipitation mechanism.