The increasing concentration of carbon dioxide in the atmosphere has intensified the need for advanced carbon capture and utilization (CCU) technologies. Nanomaterial-based CCUs offer a promising approach to achieving efficient and sustainable CO2 capture, conversion, and reuse in a closed-loop system. This chapter explores the potential of carbon-based nanomaterials (such as carbon nanotubes, graphitic carbon nitride, graphene oxides, metal-organic frameworks) to enhance CO2 adsorption and catalytic conversion. The advantage of nanomaterials, which include large surface area, tunable porosity, and selective adsorption capabilities, is that they enable effective carbon capture from industrial emissions and direct air sources. Also, integrated nanomaterial catalysts facilitate the conversion of captured CO2 into valuable chemicals and fuels, such as methanol and synthetic hydrocarbons, creating a sustainable carbon cycle. Developing closed-loop systems at the nanoscale offers a pathway to carbon neutrality by minimizing emissions and producing economically valuable products. However, scalability, energy efficiency, and material stability have been addressed to enable widespread industrial adoption. This chapter highlights recent advances, potential applications, and future directions of nanomaterial-based CCU technologies to achieve sustainable carbon management.