Carbon-based nanocompositesNanocomposites haveCarbon-based nanocomposites become powerful materials with unique properties when used as catalysts. This chapter delves into the structural features, chemical attributes, and numerous catalytic utilizations of a range of carbon-based nanocomposites, encompassing grapheneGraphene, carbon nanotubesCarbon Nanotube (CNT), fullerenes, graphitic carbon-nitride (g-CN), and their hybrid structures. The combined effects of carbon support and active catalytic sites improve the reaction speed, selectivity, and lifespan in processes like energy-related applications (including photocatalysisPhotocatalysis andElectrocatalysis electrocatalysis)Photocatalysis and electrocatalysis, pollutant removalPollutant removal, and chemical synthesis (such as heterocatalysis and biomass conversion). These hybrid carbon-based nanocomposite structures held significant value across numerous fields. Therefore, the demand forCarbon nanocomposites carbon nanocomposites is growing at a rapid pace, and the creation of innovative preparation methods wants particular attention. This chapter focuses on the key developments in the field over the past few years, examining innovative methods of preparingCarbon-based nanocomposites carbon-based nanocompositesNanocomposites and their uses in different catalytic reactions.