CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

2016 ◽  
Vol 858 ◽  
pp. 1125-1128
Author(s):  
Ioannis Deretzis ◽  
Filippo Giannazzo ◽  
Antonino La Magna

Notwithstanding the graphitization of SiC under high thermal treatment can take place for all SiC surfaces, the quality of the resulting graphene as well as its structural and electrical characteristics strongly depend on the SiC face where growth has taken place. In this paper we use the density functional theory to analyze the structural and electronic properties of epitaxial graphene grown on three different SiC planes. Calculations are presented for the (6√3×6√3)R30°-reconstructed SiC(0001) surface (Si face) as well as the nonpolar SiC(11-20) and SiC(1-100) planes. We argue that the formation of a strongly-bound interface buffer layer is an exclusive property of the SiC(0001) surface. Moreover, our results indicate that nonpolar planes give rise to graphene with a nearly ideal low-energy spectrum.


2012 ◽  
Vol 548 ◽  
pp. 281-285 ◽  
Author(s):  
Cheng Gen Zhang ◽  
Ze Min Chen ◽  
Shu Yuan Yu ◽  
Hong Chao Wei

Density functional theory (DFT) calculations are performed to investigate the structures of small silsesquioxanes (Si2nO3nX2n) (n=1-5 and X=H, F, Me). The large HOMO–LUMO gaps, which range from 5.41 to 9.17 eV, imply optimal electronic structures for these molecules. Furthermore, the substituent effect analysis indicate that the electron donating methyl group substituents lengthen the Si-O bond and largen the SiOSi bond angle, the electron withdrawing F atom substituents shorten the Si-O bond and lessen the SiOSi bond angle.


2012 ◽  
Vol 588-589 ◽  
pp. 51-54
Author(s):  
Lin Xu ◽  
Zong Lin Liu ◽  
Hong Kuan Yuan

The geometries, stabilities, electronic and magnetic properties of small GdnO3(n=1-5) clusters have been systematically studied by using density functional theory with the generalized gradient approximation. We found that the Gd atoms and O atoms in GdnO3clusters prefer three and two coordination, respectively, which origin from the electronic configurations of Gd and O atoms. The results show that Gd2O3cluster is more stable than its respective neighbors, which is reflected from its high average binding energy and high HOMO-LUMO gap. In addition, we calculate the magnetic properties of GdnO3clusters. The local magnetic moments of the Gd atom in the GdnO3clusters exhibit a weak dependence on the O atoms, which are slightly enhanced with the increasing of the number of Gd atom.


2016 ◽  
Vol 30 (25) ◽  
pp. 1650176 ◽  
Author(s):  
Shuying Zhong ◽  
Fanghua Ning ◽  
Fengya Rao ◽  
Xueling Lei ◽  
Musheng Wu ◽  
...  

Atomic adsorptions of N, C and O on silicene and molecular adsorptions of N2 and CO on silicene have been investigated using the density functional theory (DFT) calculations. For the atomic adsorptions, we find that the N atom has the most stable adsorption with a higher adsorption energy of 8.207 eV. For the molecular adsorptions, we find that the N2 molecule undergoes physisorption while the CO molecule undergoes chemisorption, the corresponding adsorption energies for N2 and CO are 0.085 and 0.255 eV, respectively. Therefore, silicene exhibits more reactivity towards the CO adsorption than the N2 adsorption. The differences of charge density and the integrated charge calculations suggest that the charge transfer for CO adsorption ([Formula: see text]0.015[Formula: see text]) is larger than that for N2 adsorption ([Formula: see text]0.005[Formula: see text]). This again supports that CO molecule is more active than N2 molecule when they are adsorbed onto silicene.


2018 ◽  
Vol 32 (15) ◽  
pp. 1850187 ◽  
Author(s):  
Zhi Li ◽  
Zhonghao Zhou ◽  
Zhen Zhao ◽  
Qi Wang

The configurations, stability, electronic properties and CO adsorption of the ground state Pd[Formula: see text]Al (n = 1–5) clusters are calculated by the density functional theory (DFT). The results reveal that the lowest-energy configurations of Pd[Formula: see text]Al clusters inherit the geometries of the host Pd[Formula: see text] clusters to a larger extent. The C atom in CO molecule prefers to approach more Pd atoms rather than Al atoms in small Pd[Formula: see text]Al clusters. Pd[Formula: see text]AlCO clusters have higher average binding energies than the corresponding small Pd[Formula: see text]CO clusters except for PdCO. AlCO and Pd3AlCO clusters possess better kinetic stability than their neighbors by the HOMO–LUMO gaps. Except for Pd6 clusters, CO molecule prefers to adsorb on small Pd[Formula: see text] clusters rather than Pd[Formula: see text]Al clusters. Both the Al–Pd bonding in Pd[Formula: see text]Al clusters and C–Pd bonding in Pd[Formula: see text]AlCO clusters have certain covalent characters.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
A. Z. AlZahrani

First-principles total energy calculations of the structural and electronic properties of Ce-doped fullerene have been performed within the framework of the density functional theory at the generalized gradient approximation level. Among various locations, Ce atom was found to engage with the six-fold carbon ring. The total energy is found to significantly change as the Ce atom being shifted from the center of the cage toward the edge close to the six-membered ring where the total energy reaches its local minimum. Moreover, repulsive interaction between Ce atom and the cage components turns as the adatom directly interacts with the six C atoms of the ring. The lowest-energy CeC60 geometry is found to have a binding energy of approximately 5.34 eV, suggesting strong interaction of the dopant with the cage members. Furthermore, fundamental key structural parameters and the total density of states of the optimized structure have been determined and compared with the available data.


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