First-principles screening of structural, electronic, optical and elastic properties of Cu-based hydrides-perovskites XCuH3 (X=Ca and Sr) for hydrogen storage applications

Abstract

In the present study, density functional theory is used to conduct an in-depth investigation of the physicochemical features of the perovskite XCuH3 (X = Ca and Sr). The CaCuH3 and SrCuH3, with lattice parameters of 3.66 Å and 3.77 Å, are synthesizable and thermodynamically stable, according to structural simulations. Analysis of the electronic band structure (0 eV) and density of states (DOS) shows that XCuH3 (X = Ca and Sr) perovskites exhibit metallic behaviour. For novel polycrystalline materials, the shear and Young's moduli as well as the Poisson's ratio are computed and the findings suggested that compounds with the formula XCuH3 (X = Ca and Sr) are ductile. Hydrogen storage qualities have been analyzed and it has been shown that the CaCuH3 and SrCuH3 have gravimetric hydrogen storage capacities of 2.85 wt% and 1.97 wt%, respectively. The SrCuH3 has the highest Debye temperature (θD) 344.41 K. The findings, taken as a whole, provide a practical strategy for developing innovative, potentially useful perovskite-type hydrides for hydrogen storage.