PMID- 38468939
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20240313
IS  - 2405-8440 (Print)
IS  - 2405-8440 (Electronic)
IS  - 2405-8440 (Linking)
VI  - 10
IP  - 5
DP  - 2024 Mar 15
TI  - New photocatalytic materials based on alumina with reduced band gap: A DFT 
      approach to study the band structure and optical properties.
PG  - e27029
LID - 10.1016/j.heliyon.2024.e27029 [doi]
LID - e27029
AB  - In this study, first-principles calculations using Density Functional Theory 
      (DFT) have been conducted, which were carried out using the Vienna Ab initio 
      Simulation Package (VASP) to examine the effect of Tl insertion on electronic and 
      optical properties of the alpha-Al(2)O(3). Alumina materials are abundant and the 
      main shortcoming of alumina for photocatalyst applications is their large energy 
      band gap and little absorption in the visible region of electromagnetic (EM) 
      radiation. Insertion of transition metals (TM) into semiconductor or insulating 
      materials is a hot approach to improve the absorption behavior of these materials 
      using DFT assessment. In the current work an analysis of the band structure (BS) 
      and the density of states (DOS); comprising both the total density of states 
      (TDOS) as well as the partial density of states (PDOS) were carried out. The BS 
      diagram revealed that various concentrations of Tl insertion into the alpha-Al(2)O(3) 
      reduced the band gap to 2.38 eV. In the density of state diagram, the band gap 
      energy shifted to lower photon energies with increasing Tl concentrations which 
      supports the BS results. The band gap obtained from the first peak in the 
      imaginary part of dielectric function is close enough to those established from 
      the BS diagram. Distinguished shifting of absorption coefficient to lower photon 
      energy (2.27 eV) reveals the suitability of the doped alpha-Al(2)O(3) for various 
      applications. The increase of refractive index (n) with increasing of Tl into the 
      alpha-Al(2)O(3) structure is evidence for the increase of charge, which is a source 
      for polarization and attenuates the velocity of light in a medium. The increase 
      of optical conductivity with photon energy started after band gap values. The 
      reflectance, absorbance and transmittance results indicate that the doped 
      alpha-Al(2)O(3) is responsive to the visible region of EM radiation while in pure 
      state almost transparent.
CI  - (c) 2024 The Authors.
FAU - Yasin Ahmed, Taha
AU  - Yasin Ahmed T
AD  - Physics Department, College of Science, University of Sulaimani, Kurdistan 
      Regional Government, Qlyasan Street, Sulaymaniyah 46001, Iraq.
FAU - Aziz, Shujahadeen B
AU  - Aziz SB
AD  - Research and Development Center, University of Sulaimani, Kurdistan Regional 
      Government, Sulaimani 46001, Iraq.
AD  - Department of Physics, College of Science, Charmo University, Chamchamal, 46023, 
      Sulaymaniyah, Iraq.
FAU - M A Dannoun, Elham
AU  - M A Dannoun E
AD  - Department of Mathematics and Sciences, Woman Campus, Prince Sultan University, 
      P.O. Box 66833, Riyadh 11586, Saudi Arabia.
LA  - eng
PT  - Journal Article
DEP - 20240228
PL  - England
TA  - Heliyon
JT  - Heliyon
JID - 101672560
PMC - PMC10926069
OTO - NOTNLM
OT  - Band structure & density of states
OT  - DFT
OT  - Optical properties
OT  - alpha-Al2O3
COIS- The authors declare that they have no known competing financial interests or 
      personal relationships that could have appeared to influence the work reported in 
      this paper.
EDAT- 2024/03/12 06:42
MHDA- 2024/03/12 06:43
PMCR- 2024/02/28
CRDT- 2024/03/12 03:47
PHST- 2023/10/18 00:00 [received]
PHST- 2024/02/22 00:00 [revised]
PHST- 2024/02/22 00:00 [accepted]
PHST- 2024/03/12 06:43 [medline]
PHST- 2024/03/12 06:42 [pubmed]
PHST- 2024/03/12 03:47 [entrez]
PHST- 2024/02/28 00:00 [pmc-release]
AID - S2405-8440(24)03060-3 [pii]
AID - e27029 [pii]
AID - 10.1016/j.heliyon.2024.e27029 [doi]
PST - epublish
SO  - Heliyon. 2024 Feb 28;10(5):e27029. doi: 10.1016/j.heliyon.2024.e27029. 
      eCollection 2024 Mar 15.