A comprehensive bibliometric review and analysis on the evolution of nanotube-based hydrogen storage materials via DFT simulations

Abstract

Hydrogen’s promise as a clean energy carrier is tempered by the challenges of efficient storage and safety concerns. While it offers an alternative to finite fossil fuel resources, current hydrogen storage methods, like cryo-compression and liquefaction, are often economically impractical. To tackle these issues, researchers are turning to nanotube materials (NTMs), crystalline substances with unique attributes ideal for hydrogen storage. Structural adaptability - NTMs can be precisely engineered for optimized hydrogen adsorption. These materials boast significant porosity, providing ample room for hydrogen molecules. NTMs offer a large surface area, enhancing their hydrogen adsorption capacity. NTMs employ weak van der Waals forces for hydrogen adsorption, enabling easy release via heat or pressure. Efforts are underway to enhance NTMs’ surface area and hydrogen uptake capabilities, along with a focus on mechanisms like the hydrogen spill-over for achieving high-density storage. NTMs go beyond storage; they can act as proton exchange membranes and fuel cell electrodes, making them versatile components in hydrogen-based energy systems. One strategy for improving NTM hydrogen storage involves introducing dopants or defects. Transition metals, due to their ability to attract and store hydrogen molecules in NTMs, are commonly explored. However, this addition may reduce the material’s gravimetric density, a critical practical consideration. In summary, research into NTMs and their potential for hydrogen storage via density functional theory is ongoing. This work explores strategies to enhance hydrogen storage, especially through transition metal doped NTMs. While these metals can improve hydrogen adsorption, the trade- offs in gravimetric density must be carefully weighed. Overall, this research contributes to the broader goal of harnessing hydrogen’s potential as a clean energy carrier, addressing the world’s growing energy needs.