Effect of iron catalyst on the microstructure and electrochemical properties of vanadium carbide-derived carbons

Carbide-derived carbons (CDCs) are obtained from vanadium carbide powders in the presence or absence of iron catalyst at chlorination temperatures of 400, 600, 800 and 1000 °C. The structural differences of the resulting carbons are characterized by low-temperature nitrogen sorption, Raman spectroscopy, X-ray diffraction, and transmission electron microscope techniques. Unlike monotonous increase in the degree of order for the CDC synthesized without addition of iron catalyst, a various decrease for the CDC synthesized with the catalyst is observed. This difference is due to the formation of many nano-diamonds during the CDC processing in the presence of iron catalyst. Variation in the specific surface area is associated with the degree of order in the CDC. CDC synthesized with iron catalyst at chlorination temperature of 800 °C shows the highest specific surface area, as well as the best electrochemical performance.