Advancements in Ti₃C₂ MXene-Integrated Various Metal Hydrides for Hydrogen Energy Storage: A Review

The current world is increasingly focusing on renewable energy sources with strong emphasis on the economically viable use of renewable energy to reduce carbon emissions and safeguard human health. Solid-state hydrogen (H₂) storage materials offer a higher density compared to traditional gaseous and liquid storage methods. In this context, this review evaluates recent advancements in binary, ternary, and complex metal hydrides integrated with 2D Ti₃C₂ MXene for enhancing H₂ storage performance. This perspective highlights the progress made in H₂ storage through the development of active sites, created by interactions between multilayers, few-layers, and internal edge sites of Ti₃C₂ MXene with metal hydrides. Specifically, the selective incorporation of Ti₃C₂ MXene content has significantly contributed to improvements in the H₂ storage performance of various metal hydrides. Key benefits include low operating temperatures and enhanced H₂ storage capacity observed in Ti₃C₂ MXene/metal hydride composites. The versatility of titanium multiple valence states (Ti⁰, Ti²⁺, Ti³⁺, and Ti⁴⁺) and Ti-C bonding in Ti₃C₂ plays a crucial role in optimizing the H₂ absorption and desorption processes. Based on these promising developments, we emphasize the potential of solid-state Ti₃C₂ MXene interfaces with various metal hydrides for fuel cell applications. Overall, 2D Ti₃C₂ MXenes represent a significant advancement in realizing efficient H₂ storage. Finally, we discuss the challenges and future directions for advancing 2D Ti₃C₂ MXenes toward commercial-scale H₂ storage solutions.