Carbon is one of the few elements known since ancient time.It exists as diamond and graphite in nature.Since synthetic carbon became available almost a century ago,it has been widely used in many fields and the best known applications are adsorbents and catalyst supports.Development of material science and nanotechnologies has allowed tailored design and synthesis of carbon allotropes with markedly different properties by combining the basic building blocks in different configurations.This has led to the discovery of Buckminsterfullerene or buckyball (C60),carbon nanotubes (CNTs),and graphene,and their derivatives within last 30 years highlighted by several Nobel Prize awards.Their superior properties of chemical stability,rich surface chemistry and fast electron mobility with rather well defined structure in contrast to classical carbon materials based on graphite and carbon black have aroused worldwide enthusiasm in many scientific and technological areas.On top of that,careful modification and decoration of these carbon allotropes with functional groups make it possible to further fine tune their properties.This has invoked significant interest in assembling them into functionalized materials for applications in energy-related processes e.g.catalytic processes,fuel cells,batteries and supercapacitors.