Improvement of structure and electrical conductivity of activated carbon by catalytic graphitization using N2 plasma pretreatment and iron(iii) loading

Abstract

In order to improve the amorphous structure of commercially activated carbon (AC) for enhancing its electron transport, nitrogen radio-frequency plasma was firstly used to pretreat AC, followed by impregnation with FeCl₃·6H₂O solutions to prepare graphitic carbon under the pyrolysis temperature of 1000 °C. Emphasis was put on investigating the structure and electrical conductivity of post-calcination samples by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) characterization, as well as measuring its powder resistivity. The results show that the structure of annealed composite samples is more ordered as the pretreatment time increased, and the maximum value of electrical conductivity is higher than that of the un-pretreated AC by 20%. Furthermore, by exploring the effect on the reaction of plasma treatment on iron loading by means of X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX), a plausible explanation can be proposed that the content and distribution of iron loaded on the raw AC play a decisive role in the later iron-catalyzed graphitization.