First-principles investigations of the structural, optoelectronic, magnetic and thermodynamic properties of hydride perovskites XCuH3 (X = Co, Ni, Zn) for hydrogen storage applications

Abstract

Hydrogen storage in current years has become significant and momentous for researcher’s interest because hydrogen as an energy source can be utilized. In the current study, the structural, optoelectronic, magnetic, and thermodynamic properties along with bader charge density parameters of novel combinations of hydride perovskites such as CoCuH3, NiCuH3 and ZnCuH3 are investigated by first principles method in the frame work of density functional theory (DFT). The comprehensive investigations have been made while using three cations (Co, Ni and Zn) in ABH3 cubical order of symmetry phases. The band structures are plotted along with partial density of states, which manifestly predict that XCuH3 (X = Co, Ni and Zn) hydrides possess metallic behavior due to overlapping of conduction and valence bands. The lattice parameters of XCuH3 (X = Co, Ni, Zn) are calculated on the basis of Generalized Gradient Approximations (GGA), which are indexed as 3.3287 Å, 3.3245 Å and 3.6129 Å for XCuH3 (X = Co, Ni, Zn), respectively. However, to dominate the limitations of GGA functional, LDA + U (an effective Hubbard parameter) has been utilized and calculated improved lattice parameters are 3.4815 Å, 3.2838 Å and 3.4867 Å for XCuH3 (X = Co, Ni, Zn), respectively. The dielectric function, refractive index, extinction coefficient, optical conductivity are calculated on the basis of Kramer-Kroing principle and their results show that NiCuH3 is more appropriate material for hydrogen storage applications. The gravimetric ratio of hydrogen storage capacities are determined as 2.8 wt.%, 3.0 wt.%, and 2.7 wt.% for CoCuH3, NiCuH3 and ZnCuH3, respectively. Antiferomagnetism is reported for NiCuH3 and ZnCuH3, while magnetism has been observed for CoCuH3 in line with the results calculated through DOS and PDOS for studied materials. The current study is the first computational attempt of XCuH3, which may contribute outstanding amelioration for future investigations in hydrogen storage applications.