Improved thermodynamic stability and visible light absorption in Zr+X codoped (X = S, Se and Te) BaTiO3 photocatalysts: A first-principles study. (August 2022)

• Record Type: Journal Article
• Authors: Zulfiqar, Waqas; Alay-e-Abbas, Syed Muhammad
• Is Part Of: Materials today communications. Volume 32(2022)
• Publication Date: 2022-08
• Subjects: Perovskite oxide -- Hydrogen production -- Photocatalytic water splitting -- Solar energy -- Isovalent doping; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2022.103867
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: Band gap tuning of titanium based perovskite oxides through chalcogen doping is an attractive avenue for realizing visible light driven photocatalysis for hydrogen production. Unfortunately, accommodating a chalcogen atom at an O-site of BaTiO3 is thermodynamically challenging owing to large differences in the atomic radii and electronegativities of oxygen and chalcogen atoms. In the present study we employ first-principles density functional theory calculations to examine the influence of Zr codoping on the structural, thermodynamic, opto-electronic properties and photocatalytic performance of X-doped (X = S, Se and Te) BaTiO3 systems. The atomic structure and energetic properties are computed using SCAN meta-GGA functional of density functional theory, while the electronic and optical properties are computed using the TB-mBJ meta-GGA potential functional. Within the valid limits of the atomic chemical potentials, we find that chalcogen doping in BaTiO3 lattice would be experimentally difficult despite a clear reduction in the electronic band gap of this system useful for application in visible light driven photocatalysis. In order to improve the synthesis feasibility of X-doped BaTiO3 under oxygen-rich as well as oxygen-poor chemical environments, we propose Zr as a codopant at a Ti-site in X-doped BaTiO3 which improves the thermodynamic stability and also retains the reduction in the electronic band gap of cubic BaTiO3 caused by the presence of chalcogen atom. Our results suggest that Zr+X (X = S, Se and Te) codoped BaTiO3 offer great opportunities as practical photocatalysts for hydrogen production through overall splitting of the water molecule. Graphical Abstract: ga1 Highlights: Photocatalytic performance of zirconium and chalcogen doped BaTiO3 perovskites are examined using DFT. SCAN and TB-mBJ meta-GGAs are employed to accurately predict thermodynamic and photocatalytic properties. Band gaps, band edge potentials, optical abosrtion and effective masses are reported. Photocatalytic performance of Zr+S and Zr+Se codoped BaTiO3 are found to be better under visible light.