Abstract <p>Hydrogen is a viable clean energy carrier for the upcoming time frame. Sustainable and renewable energy sources are now essential for tackling the world’s climate issues. In the energy sector, hydrogen storage technology is a crucial frontier, especially as countries throughout the world quicken their shift away from fossil fuels. With its environmental advantages and increased energy security, hydrogen is now a more attractive alternative to traditional fossil fuels thanks to recent developments in nano-based materials. With a focus on recent developments in material science and storage efficiency, this paper provides a thorough review of Density Functional Theory (DFT) studies of functionalized nanomaterials for hydrogen storage in nano-based systems. Our review precisely looks at several changes made to nano-based structures to maximize their capacity to store hydrogen. Numerous DFT-based theoretically investigated nanomaterials have shown amazing potential for effective hydrogen storage and will serve as a basis for experimental confirmation. A thorough review is conducted of the many alterations made to nano-based structures to enhance their hydrogen-storing capabilities. The DFT-based theoretical studies examined in this review should encourage experimental teams to verify the theoretical predictions through experimentation since numerous modified nano-based systems have been demonstrated to be promising options for storing hydrogen.</p>