This review discusses the application of density functional theory (DFT) to improve hydrogen storage in graphene-based materials. The study highlights various modifications of graphene structures, including decoration, doping, and the introduction of vacancies, to enhance hydrogen storage properties. These modifications aim to increase the reactivity of pristine graphene, making it a more effective material for hydrogen storage. The review covers different types of modified graphene, such as decorated graphene, doped graphene, graphene with vacancies, and decorated-doped graphene. It also examines the effects of different doping elements and the impact of vacancy-doping on hydrogen storage capacity. The study emphasizes the importance of DFT-based calculations in predicting the performance of these materials and suggests that experimental validation of these theoretical findings is necessary. The review concludes that modified graphene structures, particularly those with single-atom or cluster decorations, doping, and vacancies, are promising candidates for hydrogen storage, meeting the requirements set by the U.S. Department of Energy. The results indicate that these materials can store hydrogen efficiently through physisorption, making them viable options for future hydrogen storage technologies.This review discusses the application of density functional theory (DFT) to improve hydrogen storage in graphene-based materials. The study highlights various modifications of graphene structures, including decoration, doping, and the introduction of vacancies, to enhance hydrogen storage properties. These modifications aim to increase the reactivity of pristine graphene, making it a more effective material for hydrogen storage. The review covers different types of modified graphene, such as decorated graphene, doped graphene, graphene with vacancies, and decorated-doped graphene. It also examines the effects of different doping elements and the impact of vacancy-doping on hydrogen storage capacity. The study emphasizes the importance of DFT-based calculations in predicting the performance of these materials and suggests that experimental validation of these theoretical findings is necessary. The review concludes that modified graphene structures, particularly those with single-atom or cluster decorations, doping, and vacancies, are promising candidates for hydrogen storage, meeting the requirements set by the U.S. Department of Energy. The results indicate that these materials can store hydrogen efficiently through physisorption, making them viable options for future hydrogen storage technologies.