A adsorção de H2 em estruturas de γ-grafidino decoradas com metais alcalinos sob temperatura: uma abordagem computacional

Abstract

This work aims to investigate, through computational simulations, the study of H2 adsorption on γ–graphidine structures decorated with alkaline metals. Therefore, simulations based on Density Functional Tight-Binding Theory (DFTB) were performed to understand the adsorption mechanisms, thermal stability, and desorption, including molecular dynamics. The analyses included evaluating the adsorption energy and desorption temperature. Low-temperature molecular dynamics was used as a method for refining the optimization, and a heating method was used to estimate the desorption temperature. The results indicated that functionalization with alkaline metals, although reducing the gravimetric capacity for the adsorption of H2, maintains structural stability. However, it significantly increases the desorption temperature, which represents an important improvement for practical application, as greater temperature stability ensures safer and more efficient control over the release of stored hydrogen. Additionally, significant changes in the adsorption profile were observed, suggesting potential for applications in energy storage systems. It is concluded that the studied structures present promising characteristics for hydrogen storage technologies, notably improved desorption temperature stability. Future work may explore the graphdiyne functionalized with other decorative elements and the adsorption of different molecules, aiming to expand the material’s applicability.