Developing the amazing photocatalyst of ZnAg2GeSe4, ZnAg2Ge0.93Fe0.07Se4 and ZnAg2Ge0.86Fe0.14Se4 through the computational explorations by four DFT functionals

Abstract

For developing the stannite type quarterly crystal photocatalyst, the electronic structure and optical properties of ZnAg 2 GeSe 4 , ZnAg 2 Ge 0.93 Fe 0.07 Se 4 and ZnAg 2 Ge 0.86 Fe 0.14 Se 4 were calculated and compared with the parent stannite type quarterly crystal, ZnAg 2 GeS 4 . First of all, the four functionals, such as GGA with PBE, GGA with RPBE, GGA with WC and LDA with CA-PZ functionals were used for primary screening of electronic band structure and structural geometry for ZnAg 2 GeS 4 while the band gap was in 0.93, 0.97, 0.77 and 0.67 eV, respectively. It must be mentioned that the experimental value of ZnAg 2 GeS 4 was 0.94 eV so that the GGA with PBE showed the overlapping value of band gap. The main focus of this paper is to evaluate the band structure of newly predicted the stannite type quarterly crystal, ZnAg 2 GeSe 4 using four methods replacing the Sulfur atom by Serium atom on ZnAg 2 GeS 4 . The band gap for four methods, such as GGA with PBE, GGA with RPBE, GGA with WC and LDA with CA-PZ functionals, were calculated in 0.84 eV, 0.92 eV, 0.68 eV and 0.58 eV. Afterward, Fe atom was doped by two portions, like 7% and 14%, to make the empirical formula, ZnAg 2 Ge 0.93 Fe 0.07 Se 4 and ZnAg 2 Ge 0.86 Fe 0.14 Se 4 . The numerical values of band gaps for ZnAg 2 Ge 0.93 Fe 0.07 Se 4 and ZnAg 2 Ge 0.86 Fe 0.14 Se 4 were 0.43 eV, 0.53 eV, 0.35 eV and 0.18 eV and 0.24 eV, 0.31 eV, 0.18 eV and 0.08 eV, respectively, using the four respected DFT methods. For their contributed orbitals of each atom on crystal, the density of state and the partial density of state for ZnAg 2 GeSe 4 , ZnAg 2 Ge 0.93 Fe 0.07 Se 4 and ZnAg 2 Ge 0.86 Fe 0.14 Se 4 crystals were simulated through the GGA with PBE method as standard regarding the calculation of band gap study comparison with experimental magnitude. For giving the further information about the nature in case of optical evidence, the six optical properties, such as absorption, reflection, refractive index, conductivity, dielectric function and loss function were calculated, and make a comparative study. In case of UV light absorption in lighten to optical parameters, the ZnAg 2 Ge 0.86 Fe 0.14 Se 4 can show the highest absorption up to convenience energy region as photocatalyst.

Structural Insights into In Situ Disulfide Bond Formation for Enhancing Schottky Diode Behavior of a Paddle-Wheel Zn-Based Coordination Polymer

“…Further, it is noteworthy that the electrical conductivity of a material arises owing to the flow of electrons from the conduction band or holes to the valence bands. The transfer of electron density from one group to another group indicates the separation of charge during electronic transition. − To elucidate the role of component MOs and their related energy values, density of states (DOS) plots are solved. From DOS diagram (Figure ), the difference between band edges are well documented.…”

Comparative studies of Ag3PO4, Ag2CO3, and Ag3VO4 as photocatalyst for wastewater treatment: A first-principles calculation

“…The real part (σ r ) and imaginary part (σ i ) of the dielectric function ε (ω) are linked through the following expressions in equation (3) and equation (4) : here, the conductivity, as described by σ i = ωε 2 (ω), is directly proportional to the real and imaginary components of the dielectric constant. In the context of active photocatalysts, it's imperative that the band gap between the valence and conduction bands remains less than 1.8 eV [ 45 ]. As depicted in Fig.…”

“…Thus, this research endeavors to conduct a comparative computational analysis, focusing on to dissect Ag 3 VO 4, Ag 2 CO 3, tetragonal Ag 3 VO 4 , and Ag 3 VO 4 as potential photocatalysts for wastewater treatment. To achieve this goal, computational tools were employed to design these crystals and conduct a comprehensive evaluation using five Density Functional Theory (DFT) functionals: Generalized Gradient Approximation (GGA) with Perdew Burke Ernzerhof (PBE), Generalized Gradient Approximation (GGA) with Revised Perdew Burke Ernzerhof functional (RPBE), Generalized Gradient Approximation (GGA) with Perdew-Berke-Ernzerhof for solids (PBEsol), Perdew-Wang-91 (PW 91 ), and Wu-Cohen (WC) [ [43] , [44] , [45] ], chosen for their effectiveness and accuracy compared to other DFT functionals [ 46 ]. The selection of the band gap concept as the focal point of this study is rooted in the profound correlation observed between a reduced band gap and the heightened photocatalytic activity.…”

Investigation of Structural, Electronic and Optical Properties of Na2InAgCl6, K2InAgCl6, and Rb2InAgCl6 Lead-Free Halide Double Perovskites Regarding with Cs2InAgCl6 Perovskites Cell and a Comparative Study by DFT Functionals

“…Withal, it must be noted for optimization structure showing in Figures 1a to 1d which were taken after simulation GGA with RPBE which has been considered as the standard functional of DFT having heavy metal atoms in crystal. But the GGA with PBE, which has estimated the most accurate and acceptable DFT functional for calculating the electronic structure of heavy metals containing crystals [30][31][32][33][34] shows very close magnitude of band gap.…”