Developing advanced hydrogen storage materials with high capacity and efficient reversibility is a crucial aspect for utilizing hydrogen source as a promising alternate to fossil fuels. In this paper, we have systematically investigated the hydrogen storage properties of neutral and negatively charged C₉N₄ monolayer based on density functional theory (DFT). Our foundings indicate that injecting additional electrons into the adsorbent significantly boosts the adsorption capacity of C₉N₄ monolayer to H₂ molecules. The gravimetric density of negatively charged C₉N₄ monolayer can reach up to 10.80 wt% when fully covered with hydrogen. Unlike other hydrogen storage methods, the storage and release processes happen automatically upon introducing or removing extra electrons. Moreover, these operations can be easily adjusted through activating or deactivating the charging voltage. As a result, the method is easily reversible and has tunable kinetics without requiring particular activators. Significantly, C₉N₄ is proved to be a suitable candidate for efficient electron injection/release due to its well electrical conductivity. Our work can serve as a valuable guide in the quest for a novel category of materials for hydrogen storage with high capacity.

开发具有高容量和高效可逆性的先进储氢材料是利用氢源作为化石燃料有前景的替代品的一个关键方面。在本文中，我们基于密度泛函理论（DFT）系统地研究了中性和带负电的C ₉ N ₄单分子层的储氢特性。我们的研究结果表明，向吸附剂中注入额外的电子可显着提高 C ₉ N ₄单层对 H ₂分子的吸附能力。当完全被氢气覆盖时，带负电的C ₉ N ₄单层的重量密度可以达到10.80wt%。与其他储氢方法不同，存储和释放过程在引入或去除额外电子时自动发生。此外，这些操作可以通过激活或停用充电电压来轻松调整。因此，该方法很容易可逆，并且具有可调的动力学，无需特定的激活剂。值得注意的是，C ₉ N ₄由于其良好的导电性而被证明是有效电子注入/释放的合适候选者。我们的工作可以为寻找新型高容量储氢材料提供有价值的指导。