γ-Graphdiyne decorated with Y and Zr: A DFT study on hydrogen storage and material properties

Abstract

The development of efficient hydrogen storage materials is crucial for the widespread adoption of hydrogen fuel cell technology. In this study, we explore the hydrogen storage properties of Y and Zr-decorated γ-Graphdiyne (GDY) using Density Functional Theory calculations. Our results show that both Y and Zr-decorated GDY exhibit promising hydrogen storage capacities, with average binding energies of −0.36 eV and − 0.49 eV, respectively, meeting the DOE standards. Both Y and Zr can hold seven H₂ molecules by Kubas interaction, which is examined using density of states and charge transfer calculations. The gravimetric capacities for hydrogen with eight Y and Zr atoms on both sides of a supercell of GDY are 6.64 and 6.57 wt%, respectively. The desorption temperatures of the Y and Zr-decorated GDY are 265 K and 361 K respectively at ambient pressure. The diffusion energy barriers of 2.78 eV and 3.23 eV verify that both systems hinder any possibilities of metal clustering and are compatible for practical applications. Additionally, the thermal and dynamic stability of both systems are checked using AIMD and phonopy calculations. This study provides valuable insights into the design of metal-decorated carbon-based hydrogen storage materials and highlights their potential for future energy applications.