EXPLORATION OF NICKEL (NI) DEOCRATED, GERMANIUM (GE) AND INDIUM (IN) DOPED HETEROSTRUCTURES AS A MEANS TO ENHANCE HYDROGEN STORAGE CAPABILITIES. INSIGHT FROM DENSITY FUNCTIONAL THEORY (DFT)

This study investigates the potential of Nickel (Ni) decorated, Germanium (Ge) and Indium (In) doped heterostructures for hydrogen storage, utilizing a comprehensive computational approach. The research employs the M062x/def2svp level of theory and various computational tools to assess the stability, reactivity, and performance of these materials in hydrogen storage applications. The analysis encompasses Koopman's approximation to determine the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO), thereby establishing the critical energy gap (Eg) parameter. Additionally, the study includes the analysis of second-order perturbation energy using Natural Bond Orbitals (NBO) to investigate donor-acceptor interactions, providing insights into the systems' stabilization and charge transfer phenomena. Reduced Density Gradient (RDG) was employed to visualize weak interactions, highlighting the role of hydrogen bonding and weak van der Waals contacts in gas molecule adsorption. Our findings indicate that the GeNi@GP_BN heterostructure is more stable and less reactive (2.132 eV) than the InNi@GP_BN (1.916 eV) counterpart, particularly in the presence of hydrogen molecules. The calculations also support the feasibility of gas molecule/heterostructure complex formation, with GeNi@GP_BN (-1.547 eV) demonstrating a favorable adsorption capacity than the InNi@GP_BN with an Eads of (-0.684 eV).