Electronic and optical properties of nickel-doped ceria: A computational modelling study

Abstract

Cerium oxide $\text{CeO}_2$, or ceria, has gained increasing interest owing to its excellent catalytic applications. Under the framework of density functional theory (DFT), this contribution demonstrates the effect that introducing the element nickel (Ni) into the ceria lattice has on its electronic, structural, and optical characteristics. Electronic density of states (DOSs) analysis shows that Ni integration leads to a shrinkage of Ce 4$f$ states and improvement of Ni 3$d$ states in the bottom of the conduction band. Furthermore, the calculated optical absorption spectra of an Ni-doped $\text{CeO}_2$ system shifts towards longer visible light and infrared regions. Results indicate that Ni-doping a $\text{CeO}_2$ system would result in a decrease of the band gap. Finally, Mulliken's charge transfer of the $\text{Ce}_{1-x}\text{Ni}_x\text{O}_2$ system exhibits an ionic bond between Ce or Ni and O, and covalent bonds between Ce and Ni atoms. The analysis of absorption spectra demonstrates that Ni-doped $\text{CeO}_2$ is a material with potential use in photocatalytic, photovoltaic, and solar panels.

Ternary Ni-Ce-Mg-O Composites: In-Depth Optical Spectroscopy Study and Catalytic Performance in CO Oxidation

“…This can be interpreted as the appearance of a new band at 306 nm (4.06 eV and HWHM ∼ 0.65 eV) when the intensity of the initial band at 320 nm (3.87 eV and HWHM ∼ 0.85 eV) decreased. This finding correlated well with the electronic density of states (DOSs) analysis carried out by Miran and Jaf [78], which showed that Ni integration led to some shrinkage of Ce4f states.…”

Exploring structural, electronic, magnetic, and optical properties of CeO2-X (X = Pt/Ni) doped and Pt-Ni co-doped CeO2 for optoelectronic applications

“…On the other side, adding cations (Pt/Ni) with different ionic radii (1.35 Å) have caused a substantial decrease in lattice constants of Pt:CeO 2 , Ni:CeO 2 , and Pt-Ni:CeO 2 . Lattice constants of Pt doped CeO 2 were obtained to be 5.14 Å which resemble with experimental work of P Panagiotopoulou et al [54] and calculated lattice constant (5.39 Å) of Ni doped CeO 2 may be compared with experimental findings of [35,36,38]. Lattice constant of Pt:CeO 2 and Ni:CeO 2 may have good comparison with experimental findings of Asha Gupta et al [55].…”

“…Band gap of pure CeO 2 has good agreement with experimental work of I N Bazhukova et al [63], S Guo et al [64] and with theoretical findings of R Rami et al [61]. However, band gap of Ni doped CeO 2 may be compared with experimental study of Fazal Abbas et al [42], Z K Sani et al [41], J Zimou et al [38] and with theoretical results of Hussein A Miran and Zainab N Jaf [36]. Hence, band gap values as obtained in our computational study have great association with already reported works which validate our findings.…”

“…On the other side, nickel is an important dopant and is widely used for doping purposes in tuning physical properties of semiconductors. Hussein A. Miran and Zainab N Jaf [36] have theoretically calculated (using CASTEP) optical and electronic properties of CeO 2 . They found decrease in band gap and absorption is red shifted.…”

Tunability of bandgap from UV to visible region by transition metal ion implantation in CeO2 and their electronic structures

“…Various theoretical and experimental approaches are reported in the literature to modify the band gap of ceria to enhance its visible light photocatalytic activities and energy storage applications. In this context, Miran et al studied the Ni-doped ceria under the framework of density functional theory (DFT) and the doped system demonstrated a decrement in band gap [58]. However, Khan et al reported the electron beam irradiated ceria thin films approached to narrow the optical band gap from 3.36 eV to 3.12 eV through defect engineering [59].…”