Chapter 6 - Intercalation Compounds

Abstract

Graphite can accept various atoms, ions, and even molecules between its interlayer space of hexagonal layers of carbon atoms. This phenomenon is called intercalation. Characteristic of intercalation compounds (ICs) is the charge transfer between intercalates and carbon layers. This charge transfer can occur both ways, from carbon layers to intercalate and vice versa, as carbon, particularly graphite, has two kinds of carriers, negative electrons and positive holes, in its band structure. The high electrical conductivity of some ICs originates from the electronic structure change due to charge transfer between host carbon and intercalate, and therefore depends strongly on the combination between hosts and intercalates. Electrochemical and catalytic functions come from the intercalates themselves by enhancing their functions through intercalation into the carbon gallery. The synthesis of formic acid–GICs through electrochemical oxidation and their exfoliation by rapid heating is a topic under development, which calls for more research.