Study of double perovskite materials RbX2Y3O10 (X Mg, Ca, Y Ti, Zr) for photocatalytic applications: A DFT insights

The double perovskites have excellent photocatalytic capabilities and could be used for water splitting purposes. Herein, we used density functional theory (DFT) computations to inspect the compound's characteristics. Generalized gradient approximation (GGA)-Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional with compounds space group 123 (p4/mmm) are used for investigations. According to the findings, The structural characteristics show that these compounds have a tetragonal nature (a = b≠c) with 16 atoms. The electronic band structures indicate that all compounds have a semiconductor nature with an indirect energy bandgap Eg of 2.25 eV, 2.92 eV, and 2.31 eV for RbCa2Ti3O10, RbMg2Zr3O10, and RbMg2Ti3O10, respectively. According to analyses of the Mulliken atomic (MA) populations, every chemical has complex bonding with both covalent and ionic characteristics. The elastic characteristics of the perovskite revealed that it is elastically anisotropic and mechanically stable. The calculated values of Pugh's (1.48, 1.91, 4.42) and Poisson's (0.22, 0.28, 0.39) ratios indicate that the substances RbCa2Ti3O10 and RbMg2(Zr/Ti)3O10 under study are brittle and ductile by nature. As a result, we anticipate that these compounds are valuable in the growth of high-performance photocatalytic devices for water splitting for various applications like producing hydrogen and oxygen.