Abstract
This review provides a systematic analysis of the hydrogen storage methods, classifying them into three main categories: physical, chemical, and materials-based approaches. Physical methods include compressed gas and cryogenic liquid storage, offering mature yet infrastructure-intensive solutions. Chemical methods involve metal hydrides and liquid organic hydrogen carriers (LOHCs), which enable high volumetric densities and stable, long-term storage through reversible reactions. Materials-based strategies including carbon nanomaterials, metal–organic frameworks (MOFs), and doped graphene derivatives offer advanced pathways for hydrogen adsorption through physisorption and chemisorption, with promising gravimetric and volumetric capacities. Special attention is given to the influence of physical and chemical activation on carbon-based materials, as well as the role of doping, structural modification, and functionalization in enhancing hydrogen uptake. Emerging technologies such as nitrogen- and boron-doped carbon nanotubes and LOHC systems are discussed in terms of their advantages, limitations, and potential for integration into future hydrogen infrastructure. Through critical evaluation of current materials, performance metrics, and engineering challenges, this review highlights the importance of interdisciplinary innovation in storage technologies. The findings underscore the urgent need for continued research and investment to overcome thermodynamic limitations, improve kinetics, and reduce system costs. Ultimately, advanced hydrogen storage solutions are essential for achieving global net-zero targets and mitigating the environmental and health crises linked to conventional energy systems.