Fundamental Insights Toward Efficient Hydrogen Storage: Materials Design Considerations in Nanostructured and Polymer–Hybrid Systems

Hydrogen is a promising alternative energy source as the world moves toward decarbonization by reducing reliance on traditional fossil fuels. This review encompasses a comprehensive study of emerging materials for hydrogen storage, beginning with the physical and thermodynamic properties of hydrogen and the need for effective hydrogen storage solutions. Solid-state storage has attracted considerable attention because of its greater capacity and improved safety. Advancements in materials design have yielded many hydrogen storage candidates, including nanostructured materials, carbon-based nanostructures, metal–organic frameworks, porous carbon, MXenes, metal halides, functional polymers, and porous organic polymers. These materials offer many advantages but also pose important concerns, such as limited storage capacity, slow response, and ongoing structural deterioration. Moreover, the combination of polymers and nanostructured materials has emerged as an attractive solution to address these concerns. This type of hybrid material improves surface chemistry, pore architecture, stability, and enhances hydrogen uptake and kinetics. The potential implementation of hydrogen storage and its associated limitations have been thoroughly discussed.