Electronic and optical properties of nitrogen and sulfur doped strontium titanate as efficient photocatalyst for water splitting: A DFT study. (8th January 2022)

• Record Type: Journal Article
• Authors: Rehman, Jalil Ur; Rehman, M. Awais; Tahir, M. Bilal; Hussain, Abid; Iqbal, Tahir; Sagir, Muhammad; Usman, Muhammad; Kebaili, Imen; Alrobei, Hussein; Alzaid, Meshal
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 3(2022)
• Page Start: 1605
• Page End: 1612
• Publication Date: 2022-01-08
• Subjects: Photocatalysts -- DFT -- N-doped SrTiO3 -- S-doped SrTiO3 -- Optical properties; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.10.133
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: One of the most effective option of photocatalysts for water splitting is doped strontium titanate, SrTiO3 . It has a high rate of photo-generated charge transfer and limited photocatalytic activity for water splitting. The search of an appropriate photocatalyst having a high visible light absorption as well as fast charge transportation is extremely needed, however it is a difficult task. The structural, electronic and optical properties of sulfur-doped SrTiO3 and nitrogen-doped SrTiO3 are investigated using calculations based on density functional theory (DFT). According to the band structure calculations, the O-2p states represented the higher levels of the valence band of pure SrTiO3 . When S and N atoms are introduced into the SrTiO3 structure on the O site, electronic structure findings indicate that doping the Sulfur (S) atoms reduced the band gap significantly, whereas doping of N atoms increased the bandgap of SrTiO3 . According to our results, the N-doped SrTiO3 has a sufficient band gap of 2.03 eV, as well as suitable high visible light absorption and charge carrier transportation. The optical properties showed that N-doped SrTiO3 has good photosensitivity for visible light. In addition, we have found a significant impurity state that differs from O 2p-states, which can increase photocatalytic efficiency. The results of studies of electronic band structure showed that electron-hole transportation was well consistent with the experimental data. Thus, the N-doped SrTiO3 in this study is indeed an attractive candidate for hydrogen evolution throughout the visible light range, providing a logical base for the establishment of innovative photocatalysts. Highlights: The sulfur and nitrogen doping in SrTiO3 improved the electronic, optical, and structural properties. Synergistic effect of (S and N) codoping enhances a visible-light absorption of SrTiO3 . The low recombination rate and charge carrier transportation supported to improve the hydrogen efficiency.