摘要： Owing to their unique properties, nanocomposites, nanostructures, and nanomaterials are playing a key role in energy conversion and in energy storage applications. In recent years, carbon-based nanostructures are used to meet the future energy demands. Nanostructured carbon nitrides (C3N4) are very attractive candidates for energy-based devices due to its high hardness, low friction coefficient, and steadfast chemical inertness. It has a great potential in solving the issues related to energy and environmental applications. Graphitic carbon nitride (g-C3N4) is one among the carbon-based nanostructures which has attracted enormous attention in green technologies for arresting solar energy, energy storage, supercapacitor, fuel cells, electrocatalysis, and environmental remediation as well as for electronic and composite industry. g-C3N4 is a well-known polymeric materials mainly consisting of carbon, nitrogen, and is also one of the oldest material discovered in 1843. It is considered as an artificial polymer in the scientific literature [1]. Its structure is shown in Figure 12.1.