ABSTRACT
Carbon is one of the most common elements owing to its unique electronic configuration that allows it to achieve various hybridizations. The different types of hybridization in fact allow carbon to exist in different structural configurations while retaining the purity of the carbon atom. Such structural configurations are known as allotropes. In general, carbon mostly exists in three well-known allotropic forms, like diamond, graphite, and fullerenes. Diamond is an sp3 hybridized tetrahedral structure, whereas graphite has sp2 hybridized planar hexagonal structure stacked together by van der Waals forces. Recently, the invention of monolayer of graphene has revolutionized the field of research because of its unique semimetal characteristics. While zero-dimensional sp2 hybridized fullerene demonstrated a cage like spherical structure, cylindrical carbon nanotubes (CNT) presented a one-dimensional structure. CNT has generated immense interest in researchers due to its exceptional multifunctional properties applicable in various interdisciplinary fields, which will be discussed in the later sections.
